Category Archives: Loudspeakers

Why do power amps need to be matched to speakers?…

Even newcomers to the world of high end audio usually realize that when purchasing speakers, they need to find the right power amplifier to drive them.  But when listeners shop for power amplifiers their main criteria is typically “watts per channel” and “total harmonic distortion” (THD – The THD wars. Why lower distortion often doesn’t equal better sound quality) and when they shop for speakers they often look at their power handling ability and/or what their rating is in “Ohms”.  If speakers are rated for X watts/channel and they buy a power amplifier that is rated to produce X watts/channel than everything must be good in the world, right?…  As usual, the specifications that are thrown around the most don’t tell the whole story.

So what do you look for when shopping for a power amplifier to drive the speakers you’ve chosen for your listening room and musical tastes (Why do speakers need to be matched to room acoustics?…)?  Start by looking at the basic physics involved.  If you have very large planar panels such as ESLs (Electrostatic Loudspeakers) or “Maggies”  (In a nutshell, the big Maggies (3.7Rs) are a fantastic speaker, but are very dependent upon room acoustics) you are gonna need a massive, high-current power amplifier to move these panels.  Why?  Because these speaker designs do nothing to help with efficiency in creating sound waves, such as horn loading for mid and high frequencies and/or box enclosures with a tuned bass reflex port or transmission lines for mid to low frequencies.  They are engineered for complete, no-compromise accuracy and the room is the speaker enclosure (Planars… The room is the enclosure).  When you think of it in this context, the enormity of the task at hand becomes apparent, especially for larger rooms.  It’s no wonder you will need a colossal power amplifier (or two – Horizontal bi-amping with non-matching amplifiers and Why bi-amping isn’t always what you may think) to make your chosen speaker “sing”.  I’ve got modest sized Maggies (MG-12s) in a small and efficient listing room in Canada and still often drive my 70 pound, high current Nakamichi PA-7 (The Nakamichi PA-7 power amplifier) to the verge of clipping whenever I feel like “cranking it”.

Loudspeakers with a low “Ohm” rating are known to be difficult to drive, but how does this explain why the Rodger’s LS3/5As (What is it about the Roger’s LS3/5A?…) which are rated at 15 ohms and are very small “bookshelf” speakers will make a power amplifier sweat far more than a pair of 4 ohm large, floor standing Kef 104/2s (The Venerable Kef 104/2)?  The answer is it doesn’t, there is far more to the story.  In this case the 104/2s are a relatively efficient loudspeaker in spite of their large size and the LS3/5As are notoriously inefficient in spite of their small size.

Some speaker manufacturer’s have decided the power amplifier/speaker matching for you by including power amplifiers in their designs.  Meridian is well know for this, for example.  While this is a good approach in theory, it often falls short in execution and it limits the listener to their particular choice in speaker drivers.  As far as I know, there are no self-powered planar loudspeaker designs for example, perhaps because the high-current power amplifiers required to drive them are so massive and usually tip the scales at well over 50 pounds each.

While planar speaker designs require massive power amplifiers, large but efficient speakers such as the Kef 104/2 can be driven nicely by a 70 watt-per-channel, 40 year old, small and relatively light Audionics of Oregon CC-2 (The Audionics of Oregon CC-2. More distortion, more better.) with aplomb.  Why?…  In part due to the high slew rate of this little beauty but also a synergy of sorts.  Where specifications fail, listening tests come into play (listening tests vs. test measurements).  Being far more subjective, it is the only way to be certain you have a good match for your listening room and music tastes.  As such, demo your chosen power amplifier at home when ever possible.  Failing that, try to audition it powering exactly the same speakers you own in a listening room that matches those in your home as closely as possible.

More techy details can be found at: http://www.sengpielaudio.com/calculator-AmplifierLoudspeakerAndOhm.htm

The Venerable Kef 104/2

What can I say.  I purchased these speakers off Craig’s List on Maui and talk about a “gem in the rough”!  I am very, very happy with them, especially the more I play them.  So much so that I’m on the hunt for another pair for Canada.  They are something worthy of growing into.  I found them early on in my return to my love for high end music reproduction, so they started out playing SACDs coupled with a nice warm Marantz preamp and an utterly competent vintage SAE power amp.  They immediately started to reveal the weaknesses in my system in other areas, such as that of my SACD player’s DACs (Op Amps are holding back my digital quest).

But the real magic started to happen once I got my vinyl signal path going with the Denon 103R moving coil phono cartridge (The formidable Denon 103 vs. 103R low output moving coil phono cartridges – is there really a difference?…) , the right preamp for the job of handling said phono cartridge (The Nakamichi CA-5A preamplifier), and the perfect power amp to drive these amazing loudspeakers (The Audionics of Oregon CC-2. More distortion, more better.).

At the risk of using superlatives, the 104/2’s are visceral in the best sort of ways, vs. the analytical qualities of “Maggies” (In a nutshell, the big Maggies (3.7Rs) are a fantastic speaker, but are very dependent upon room acoustics).  It seems strange to call these seemingly mutual exclusive qualities both good, but they are!  All I can say if you seek perfection in the plucking of a string as part of an acoustic performance, go for the Maggies.  But if you want to rock your world like you are at a live show of your favourite classic rock band, the 104/2’s will absolutely steal the show every time.

When setting these up, it was immediately apparent that my room is by far my biggest limitation (Why do speakers need to be matched to room acoustics?…).  Very early on I discovered a dramatic improvement in imaging by not toeing them in (as you do most speakers) and much tighter bass just by moving the them about 6” further out from the rear wall.  My room is gonna resonate at around 75 Hz no matter what, since the “long” dimension is 15 feet long.  But there are still ways to work with that, especially with an acoustic suspension vs. bass reflex design.  Interestingly, the 104/2s are neither.  They are about the most clever design to get exemplary bass out of a relatively small cabinet I’ve ever seen.  The key to their success is two vertically firing woofers that combine their output to a port of exactly the same diameter as the B110 mid-range drivers, a design Kef calls “Coupled Cavity Bass Loading”.

The CC-2 powering the Kef’s is a marriage made in heaven (after all, the designer of the CC-2 was working alongside Lynn Olson who was designing speakers spec’d with Kef drivers).  As a side note, the CC-2 is also a perfect match for the 15 ohm LS3/5As I built in Canada (What is it about the Roger’s LS3/5A?…).  How do I know this?…  I listened to them together back when they came out in the 70s – another audiophile magic combination (Why do power amps need to be matched to speakers?…).

Trust your ears… (not the forums)

So shortly after I got my first pair of Kef 104/2s (The venerable Kef 104/2)  I did some tweeter surgery as all the forums say the ferro fluid in the T33s should be toast due to age.  Well, all I’ve gotta say is don’t believe everything (or much of anything) you read in the forums and trust your ears.  I thought they sounded fine but did it anyway and it made no difference what-so-ever.

Having said that, the Kef T33 tweeter is undoubtably the weak link of the 104/2s and I have no idea why Kef didn’t utilize the far better T27s of Rodgers LS3/5A fame (What is it about the Roger’s LS3/5A?…).  In any event, I subsequently upgraded to a new Vifa equivalent that upped the ante for the clarity of the high frequencies and mates perfectly to the obsolete T33’s specifications.  It also fits nicely in the 104/2’s cabinets without major modifications.

How to upgrade your existing system without spending a nickel.

If you walk into a high end audio dealer’s showroom, notice if they start asking you questions about your music tastes and listening room.  If given a chance to and they still just point you straight at their latest shiny new component and ask, “what’s your budget”, walk out.  Or… know that you are going to have to work with a very limited knowledge based and/or a profit motivated sales person.

This may sound harsh, but all the shiny objects in their listening room mean nothing as compared to the knowledge of how to set up the gear matched to your room and music preferences (Why do speakers need to be matched to room acoustics?…).  I went into a dealer of Martin Logan ESL’s in Calgary and they had a pair of their high end CLX’s (MSRP starts at $25k USD) just a few inches from the back wall in a large listening room, so I said, “let’s pull them out and give them a listen”.  The sales person gave me a blank stare in return then said, “why would we do that?”  By that time I had already noticed many unaddressed deficiencies in the entire set up, but was incredulous that they were honestly unaware that this fine set of planar speakers needed to be placed well into the room (at least two feet, probably more in this case) in order to image properly.  I glanced at the source components available, saw only a Redbook quality CD player, then replied, “never mind”, and walked out.  Granted, this particular dealer was more about Home Theatre installations.  But, still…

So here’s “the goods” on a few simple (and free) things you can do at home to get the most out of your system (if you have bookshelf speakers you will need floor stands):

  1. For most speakers, start out by setting up an equilateral triangle between your listening chair and your left and right speaker.
  2. Listen a bit, then start to experiment.  Look at your speaker manual and see what they recommend.  Most speakers like to be at least a couple feet off the rear wall.  Many planar speakers need more, some box speakers less.  Move your listening position if needed (and possible) to accommodate how far your particular speakers like to be out.  Also consider how far your listening position is from the wall behind it.  If it’s around five feet or more it can probably be ignored, but less than that and you will have significant room reflections reaching your ears from that wall.  If you’re in a rectangular room, be aware of the obvious room resonant frequencies based upon wave lengths that equal the dimensions of the room and therefore correspond to and reinforce specific bass frequencies.
  3. From there, start to experiment with how far the speakers like to be apart from each other.  You may be limited by side walls and/or furniture on the sides.  As a general rule, most speakers perform best when at least two feet from any side walls.  If this isn’t possible for your room, do your best then work on it some more in step six below.
  4. Play around with the toe-in.  This drastically effects high frequencies and the stereo image.  Most speakers like to be pointed directly at you, but some like to be pointed straight ahead.  I was amazed at the difference it made for my Kef 104/2’s (The venerable Kef 104/2) when I discovered they were of the latter variety.
  5. Next experiment with the height of your ears in the listening position.  You can do this by sitting up or slouching down.  This is one of the easiest ones to dial in because you don’t need to get out of your chair and move things around to do it.
  6. OK… so now that you’ve got your speaker placement as best as possible “as is”, it’s time to work with the room.  Consider the following diagram:
    Reflection, absorption, and diffusion in various materials.

    Your room is likely to be a combination of all three.  The first place to turn is any windows and/or mirrors in the room.  These are high acoustically reflective materials which will have a dramatic effect on sound quality.  If you have a huge glass window on the rear or side wall(s) for example, you will need to decide whether it is enhancing or detracting from sound quality (it’s almost never neutral, especially with planar speakers and a reflective surface on the rear wall).  If you have blinds, listen to one of your references (What is a “reference”?) with them both open and closed,  If you have no blinds or metal blinds, maybe temporarily hang a blanket and do the same thing.  If your system sounds better with the blanket there, you may be able to effect a more permanent solution with fabric blinds that accomplish much the same thing.  I’ve seen many, many home theatre installations with a huge flat screen located directly between the two front speakers.  Makes sense for HT?… sure.  But if you’re also listening to two channel audio on your system you will want to consider the effect this is having on your stereo imaging.  It’s almost certainly scattering and destroying it.  Solutions include in-wall screen installations with roller blinds or slides that offer a more suitable material for your music listening sessions.  It’s difficult (to say the least) to incorporate HT and 2 ch audio into a singular system, but that’s another topic (The most obvious difference between 2 channel audio and 5.1 home theatre.).  After working with all obviously highly reflective surfaces, turn to some of the more subtle room acoustics.  If you’ve got resonant bass frequencies, try to find ways to break up the wavelength.  This can be accomplished by moving furniture or even large plants around.  If you have disparate materials on your side walls you may want to find a way to address that with a bookcase to absorb side reflections or glass framed artwork or a mirror to enhance them.  Play around and have fun while thinking of all the money you are saving by working with what you’ve already got sitting around the house. However, it’s important to keep in mind the importance of sound proofing for moveable walls in order to minimize noise and disruptions between rooms. There is certainly a more acoustically engineered approach (using sound spectral analysis and expensive acoustic treatment panels), but it ultimately boils down to what sounds best to you anyway.  Unless you have a completely dedicated sound room you’re likely working with household furnishings that dramatically effect your sound quality anyway, so why not use them to your advantage?   If you’re finding very significant improvements to your sound quality based on this step, you may want to play around with steps one through five again.  This isn’t necessarily a linear process.  You may even find that after many hours in the listening chair you want to play around with all the above steps again.  I’m usually not completely satisfied until I’ve listened to references from all genres of my music collection.  That’s why it’s best to wait a while for steps seven and eight.  As a side note you may also want to wait to buy high end speaker cables (Speaker Cables) until you’ve got your speaker position nailed down.

  1. Now that you’ve got the optimal speaker positioning based upon all the variables, mark it somehow – perhaps blue tape under the speaker outline on a hardwood floor.  I line up mine with the grooves in the hardwood.  If you have carpet, get creative.
  2. Finally you will need to figure out the best way to couple the speakers to the floor.  For floor-standing models it’s simple, spikes for carpeted floors and rubber feet or spikes on small circular plates (about the size of a penny) for hardwood.  This is saved for last since moving heavy spiked speakers around on hardwood floors and protecting them at the same time is a real pain in the ass.  And… this only serves to tighten the bass frequencies and therefore has little to no effect on steps one through six above.  If you have bookshelf speakers on stands, they won’t have much bass to start with, and even less if they aren’t coupled to the floor somehow.  For my LS3/5As (What is it about the Roger’s LS3/5A?…), I found speaker stands with spiked feet that I could fill with sand for mass loading (Acoustic isolation for turntables – to couple or decouple?…).  Not as good as a well coupled floor standing speaker, but the LS3/5A was originally designed as a studio monitor.  It was only later discovered and adopted by audiophiles as a go-to speaker for high quality sit-down-and-listen music reproduction.

I find that it definitely takes a while to dial in the sweet spot of all the above, but it’s so, so worth it.  On Maui I need to move one of my speakers into place each time I sit down to listen to music.  Small price to pay (even though it weights 70 pounds).  In Canada I’ve been able to locate the Maggies in their “sweet spot” and leave them there without detracting from my living room view and esthetics, at least in my opinion.

Why do speakers need to be matched to room acoustics?…

So Magnepans (fondly know as “Maggies”) have been around for 47 years, and I was lucky enough to own a pair of their top of the line (TOTL) Tympani 1Ds 37 years ago now.

The original Mangepan Tympani 1D. A revolutionary loudspeaker to say the least.

I owned those Tympani 1Ds through a transition period in my life that saw them in many, many locales and many different listening rooms.  From my cramped teenage bedroom in Portland, Oregon to my even more cramped (and shared, I had an understanding roommate) dorm room at a Vermont ski racing academy to various other dorm rooms and apartment living rooms in Florida during university.  The Tympani 1Ds are a prodigious loudspeaker and, even with their three panels neatly folded up, they are over six feet high and weigh over 80 pounds each.  So I guess that speaks volumes for how much I loved them – since they travelled with me from Oregon to Vermont to Florida and I’d eat ramen noodles as my main meal of the day before I’d even considered selling them to pay rent.

They are often referred to as “the best Maggies ever made” and I wouldn’t be one to dispute that.  My Tympani 1Ds were my “keeper” speakers after years of trading audio gear to pay for university and I finally had to let them go back in 1984 for those last tuition payments.  They remain the best sounding speakers I’ve ever owned.  But the Martin Logan Sequel IIs I purchased shortly after graduating never had a fair chance since by that time I had sold my vinyl and had converted to CDs and my days as an audiophile looked doomed.  But that’s another story (The “Dark Ages” of High End Audio).

So why am I going on about my beloved Maggies when the topic of this post is matching loudspeakers to room acoustics?  Well…  Maggies send this point home like no other loudspeaker.  They are one inch thick panels and, as such, the room is their speaker enclosure (Planars… The room is the enclosure).  They require the same amount of care in size and placement in the room as the drivers of typical box speakers do in their cabinets.  In spite of this, their three hinged panels (one containing the tweeter, another the midrange, and the third the bass) allowed you to play around with the angles and room reflections and thereby custom configure them to any room like no other loudspeaker I’ve ever owned.  I could always make them “work” for the room they were in, albeit they worked better in some rooms than in others.

Magnepan’s newer loudspeakers lack this flexibility and the room can be a total deal-breaker for your chosen model (In a nutshell, the big Maggies (3.7Rs) are a fantastic speaker, but are very dependent upon room acoustics).  The first and foremost component in any high end audio system is the room.  This can be a good thing as long as you recognize it early on and work with it.  If your choice in room is already set, it will determine most of your other components (How do I choose a turntable?).  You start with your room acoustics and music tastes then go from there.  The rest becomes pretty easy.  It’s absolutely critical that you match your speakers to your room.   Let me say this again…  you must match your speakers to your room, otherwise you are wasting money and chasing your tail.

On Maui, my room was far more constricted than in Canada and was by far my biggest limitation.  I’ve shipped Maggies to Maui to try them and even their smallest model doesn’t work.

I tried to get Maggies to work in my Maui room to no avail

So instead I found a pair of “box speakers” that match it’s acoustics nicely (The venerable Kef 104/2).  Soon afterwards I discovered I could improve the bass quite dramatically by moving the 104/2s just a few inches further out from the wall.  My room on Maui is gonna resonate at around 75 Hz no matter what I do, since the “long” dimension is 15 feet.  But there are still ways to work with that, especially with an acoustic suspension vs. bass reflex design.  Interestingly, the 104/2s are neither.  The are about the most clever design to get exemplary bass out of a relatively small cabinet I’ve ever seen.

The Key 104/2s are the most speaker my room acoustics on Maui can handle.

Maggies on the other hand often love acoustically reflective surfaces behind them for imaging (careful with this though), so I have the perfect scenario for them in Canada – sitting out in front of a bay window where I can open or close the blinds to enhance or diminish this effect.

Comparing Magnepan MG-12s and MMGs in my listening room in Canmore.

Far too many listeners fall victim to loving a speaker when they listen to it in the high end dealer’s listening room, then are disappointed when they listen to the same speaker at home.  Sure, after a while a seasoned audiophile will get to know their room enough to know if a speaker they listen to at the dealer is likely to work at home, but even then it’s “shooting in the dark” until you are actually sitting in front of them in your listening chair at home.  To that end, most high end dealers will let you take a pair of speakers and demo them at home before you buy them.  Most will also help to set them up for the in-home demo, but I still recommend experimenting with various positions yourself.  Even fractions of inches in placement and/or orientation can make huge differences in stereo imaging and sound quality, especially for high end speakers and even more so for high end planar speakers such as Maggies.

It’s funny, but recognizing the importance of room acoustics usually saves you money on your audio system.  Why?…  Because you don’t waste money on speakers that are too big or otherwise mis-matched to your room – speakers that often cost more but sound worse than those that are properly matched to your room acoustics (How to upgrade your existing system without spending a nickel.).  I’ve gone so far as to email floor plans, room renderings, and room surface descriptions to speaker manufacturers for recommendations.  Be picky in your first and foremost high end audio purchase, the right speakers for your room and the types of music you enjoy listening to in it.

How do I choose a turntable?

I know this sounds complicated, but your turntable decision is ideally based on your choice of phono cartridge, which in turn is based on your speaker selection, which is completely based on your room acoustics.  At least this is the case when you start going for audiophile quality sound.  That’s why when I’m asked, “What’s the best turntable for my budget?” my answer is always, “That depends”.  It’s impossible to take any portion of a high-end audio system out of context and make recommendations.  Optimizing for many variables then matching components is the path to audio nirvana.  The most fixed variable is typically the room.  So that, along with musical taste, are  usually the starting points.

My room on Maui is a perfect example, where I have a very tight space combined with limited options for speaker/listener placement.  Therefore, room acoustics are my biggest limiting factor.  I’ve tried and simply can’t get planer loudspeakers like Maggie’s to work.  And I never will short of renovating to add more room and therefore more options, which I plan to do.

On the other hand, my Kef 104/2s (The Venerable Kef 104/2) are awesome for my room on Maui.  This is especially true once I figured out to pull them a few inches further into the room to avoid the reinforcement of the frequency associated with the depth of the room and not to toe them in… at all.  But my Kef 104/2s likely wouldn’t sound as good in my room in Canada, which has very different dimensions and surfaces.

My listening room in Canada is not only larger, but is also far more flexible in regard to speaker/listener positions.  After a great deal of positioning and experimentation, my Magnepan (Maggie) MG-12s perform all the magic they are supposed to, though they are the largest Maggies I can fit without room acoustics having a detrimental effect (In a nutshell, the big Maggies (3.7Rs) are a fantastic speaker, but are very dependent upon room acoustics).   So I know by now you’re probably thinking, “But I asked about turntables, why go on about speakers?”  I’m getting there.

So the reason you need to discover what speakers work best with your room acoustics and music tastes before you can choose a turntable is due to phono cartridge selection.  The loudspeakers and the phono cartridge are the two main transducers in an analog signal path (It’s all about reducing mass for the transducers) and as such, they need to be matched to each other as much as possible.

Moving coil phono cartridges, for example, have some inherent characteristics that will show themselves on nearly all loudspeakers, but they really shine when mated with similarly low-mass speaker designs such as planars.  Conversely, cone and/or box speakers might like a moving magnet phono cartridge better.  Or… a better way of thinking of it is the incredibly fast transient response offered by a high-end moving coil phono cartridge may be lost on a high-mass speaker design that simply can’t keep up, so why add the extra expense (especially when you factor in the cost of a pre-preamplifier or step up transformers).

So by now you probably figure I’ve moved on from describing loudspeakers to describing phono cartridges, but still not answering the question about turntables.  Here’s why.  Some phono cartridges are very picky about what kind of tonearm you run them in.  The Denon 103R is perhaps the most demanding phono cartridge in that regard and absolutely requires a very low compliance tonearm in order to perform properly.  So what’s tonearm compliance, you may ask?

Think of it like the chassis of a car.  If you have a very stiff suspension (and the cantilever of the Denon 103 is very stiff indeed) and a very light chassis the springs are going to push the chassis around when the wheels hit bumps and the car will get thrown all over the place.  That’s exactly what happens when you put a Denon 103R (or any other phono cartridge that requires a low compliance tonearm) into a low mass (i.e. high compliance) tonearm…  it throws it around, big time.  So much so you may be lucky if the needle even tracks the groove at all.  Even if it does it will sound terrible.  Conversely a low compliance tonearm will push a high compliance phono cartridge stylus around, having the same negative effect.

So I’m finally getting to turntable selection.  You want to determine what phono cartridge you are running before selecting a tonearm (and turntables typically come with tonearms) or risk a major compliance mis-match.  Of course, you could first select your tonearm from the high-end ones that are sold separately then choose your turntable based on your tonearm selection, which many audiophiles do.  But if you’re already that far down the rabbit hole I’m likely preaching to the choir.

Now that you know whether you are looking for a turntable with a high compliance or low compliance tonearm, how do you shop for what you’re after.  Unfortunately, even amongst the high end offerings, very few present day turntable manufactures specify it.  But here’s where common sense can prevail.  If it looks massive and therefore designed for low compliance phono cartridges, it probably is.  Conversely if it looks low mass and obviously designed for high compliance phono cartridges, it probably is.  And… if it looks light only because it is cheaply made with no consideration for phono cartridge compliance what-so-ever, it probably is.

Unfortunately. modern turntables with retail price tags under $1k mostly fall into this last category.  Don’t get me wrong, the vinyl revival is a beautiful, exciting movement.  But I’ve come to realize that it’s genesis is not due to a demand for quality, but rather due to far more insidious motivations on the part of the music industry (The new (old) gear coming out).  To that end, there will be a barrage of turntable offerings that have little to do with sound quality and far more to do with selling records again.

So what is one to do?…  Well, modern day, audiophile quality turntables start at around $5k and for that amount you can find several viable options.  Even in that arena many turntables are missing the essential tonearm compliance mark.  They build quality turntables that get bigger as they get more expensive.  To that end, one may pay far more for a bigger turntable that has a 12 inch tonearm vs. a 9 inch tonearm, only to have spent more for inferior performance with their selected phono cartridge.  I honestly don’t know how this can be lost on the modern day audiophile world, but it often is.

Or one can go vintage, back to a time when phono cartridge compliance was accounted for, resulting in several offerings, a good example is the Infinity Black Widow tonearm for high compliance.

The Infinity Black Widow. A good example of a low mass, high compliance tonearm.
The Infinity Black Widow. A good example of a low mass, high compliance tonearm.

Or if looking for a low compliance tonearm one could shop for the likes of a Fidelity Research FR-66S.

Fidelity Research FR-66S
The Fidelity Research FR-66S. A good example of a high mass, low compliance tonearm.

That said, it’s pretty easy to eye up the offerings of vintage turntables and judge by the design and size of the tonearm which camp it’s in.  Most turntable manufacturers of that era (The “golden age” (of vinyl)) went one direction or another and it’s immediately apparent.

Oh yeah… then there’s the question of direct drive or belt drive turntables.  That’s another can of worms, covered in this post:

Turntables – Direct Drive vs. Belt Drive

What is it about the Roger’s LS3/5A?…

I remember like it was yesterday the first time I heard a pair of Rogers LS3/5As, property set up on stands well away from all walls of a well dimensioned listening room.  Get in the sweet spot, close your eyes, and you simply won’t believe your ears.  Their imaging was so good that you will swear the speakers are far bigger than they are since the soundstage is so expansive.  It’s like a magic trick.  To this day if they were set up with a curtain hiding them, you could lift that curtain revealing these very small studio monitors to stares of disbelief and dropped jaws.  I guarantee it.

I first built a pair of the acoustic suspension design Rogers LS3/5A’s using  Kef T-27 and  Kef B-110 drivers back in 1978, which is 37 years ago as I write this.  I built those speakers for around $150, buying the drivers wholesale, rummaging around for top quality crossover components, and building the cabinets from scratch in a primitive home work-shop.  I paid very close attention to the quality of the crossover components, selecting mylar capacitors in matched pairs for tolerances and even had the inductors (coils) hand-wound.

Only the very finest components are selected for the crossovers
Only the very finest components are selected for the crossovers

The crossovers were assembled onto a “project” peg board since printed circuit boards for the LS3/5As weren’t available separately until much later.  It was an attempt at the time to upgrade and tweak the original design but I dropped the ball on building the cabinets strictly to the BBC’s specifications, an aspect of design that I underestimated at the time.  As such the final product ultimately fell short of the original LS3/5As made by Roger’s.

Back in 1978 the LS3/5As retailed for $400 a pair, which was top dollar for a small bookshelf speaker.  They are now collectable and I’ve seen them used on eBay from $4k to $6k, depending on their condition, serial numbers, and authenticity.  They were widely licensed with several variants subsequently released, the most prominent of which was from Falcon Acoustics.

So pretty early along my path back to high end audio I stumbled upon a pair of Kef T27 tweeters, scavenged from Kef speakers that were nearly 40 years old (An Edmonton audio-venture (names changed to protect the guilty)), grabbed them, and thereby committed to building a pair of LS3/5As again.

I brought those Kef T27s to Maui, thinking I’d build the LS3/5As there with some Kef B110 drivers I planned to scavenge from a salvage pair of Kef 104/2s that had been given to me.  When I went to remove those B110s from the cabinet it became immediately obvious there was something very wrong.  In fact, the B110’s Kef used in their 104/2s was integrated into the cabinet, rather than bolted onto the baffle.  I soon realized that it was impossible to remove the B110s from their integrated and filled cabinet without destroying them, so back to Canada my cherished T27s went.

Nearly a year passed, I found a good deal on a perfect pair of stands for my future LS3/5As, but still all I had were tweeters and stands.  Finally I got motivated, purchased a Falcon Acoustics (from England) kit for everything but the T27s, ordered a soldering iron and rosin core solder, and got started. I was further delayed by incorrect parts arriving, reordering… the usual DIY kind of stuff.

Then one day I was staring at everything I needed laid out on my kitchen table and thought, “today is the day, I’m gonna be listening to these tonight.”

All the parts (except the T27 tweeters) to build a pair of Rogers LS3/5As
All the parts (except the T27 tweeters) to build a pair of Rogers LS3/5As

There were a few puzzles along the way, per usual, but perseverance prevailed.  I checked and double checked everything. The first time I built a pair of these I fried my T27s by not properly stripping the insulation off the inductor wire prior to soldering.   I finished one and hooked it up and much to my delight everything seemed (and sounded) in order.  So I finished the other one and put them both on the stands I had already purchased and filled with sand for mass loading (sand is plentiful when you live on a golf course… sand traps ;-).  Then I tweaked positioning for my sweet spot and played some background music for a few hours to loosen them up.

The Rogers LS3/5As set up properly - on stands with plenty or room all around the to breathe.
The Rogers LS3/5As set up properly – on stands with plenty or room all around the to breathe.

Then, finally…  37 years after I built my first pair, I got to listen to the famous LS3/5A again.  I was afraid nostalgia might have gotten the better of me and my fond memories would be squashed by the “absence makes the heart grow fonder” syndrome.  Not so…  So not so.

Everything I remembered fondly about these babies came alive when I put on my reference recordings (What is a “reference recording”?).  First and foremost, figging unbelievable sound staging, that’s their strongest suit.  But soon thereafter I started to hear the subtleties in the high frequencies and the amazingly solid mid bass.  These are never gonna defy the laws of physics and produce low bass, but what’s there is so good that it doesn’t feel like you’re missing much.  And…  did I mention the sound staging?..   They definitely seem to defy the laws of physics in that department.

So my Kef 104/2 reference speakers (The venerable Kef 104/2) share the same B110’s (two per speaker in fact) but in those speakers their duty is regulated to mid frequencies and they perform flawlessly.  But the 104/2s have a seemingly inferior T33 (Trust your ears… (not the forums) handling the high frequencies.  I have to wonder why Kef would have sold their best T27 tweaters to Rogers for the LS3/5As then subsequently handicapped their own reference speakers with the T33s (the one’s in my 104/2s are now replaced with Vifa’s designed to the same specs)?

Are the T27s really that much better or did the Rogers engineers hit it out of the park with their crossover design?

The crossovers for the LS3/5As are a big part of what makes them so magic.
The crossovers for the LS3/5As are a big part of what makes them so magic.

Or did the BBC engineers somehow play a role in the magic of the LS3/5As?…  Or, as is so often the case, it’s not any one of these things but the synchronicity of all of them that culminated in the sublime?

I don’t think these questions have ever been answered, though they have certainly been voiced by audiophiles world wide.  That’s how good the LS3/5As are.  For my part I not only don’t know but, and this is one of the only times you will hear these three words from this curious audiophile, “I don’t care”.  What counts is that I now have a pair sitting on stands in my living room that will share time in Canada with my Maggies, depending on what flavor of greatness I’m in the mood for.

Headphones, Earspeakers, or whatever you want to call them…

So Stax has been making headphones, or earspeakers as they prefer to call them, since 1960.  That’s right…  55 years and counting as I write this.  They have been the de-facto standard ever since, and most still consider them to be the best you will find if you need to throw some “cans” on your head.  Interestingly, their technology has changed very little since their inception, which is why I’ve also included them in the “vintage” category, even though I purchased a pair that were manufactured in 2014.

They are still manufactured exclusively in Japan and if you want a pair you need to purchase from a dealer who imports them or import them yourself.  I purchased the 4170 system, which ships complete with a tube headphone amplifier and the SR-407 headphones.  But with Stax, nothing is as it seems and the headphones are actually mini electrostatic speaker panels (hence the terminology of “ear speaker”) and the headphone amplifier is not just an amplifier but also provides the high voltage these electrostatic panels need in order to produce music.

These ear speakers offer what is arguably the finest transient response, imaging (more on that later) and detailed frequency response available in a pair of “headphones”.  Interestingly but not surprising, they also lack emphasis in the bass department, just as similar planar loudspeakers also lack it.

I’ve never been a fan of listening to music on headphones and was hoping these “ear speakers” might change that.  I’ve always maintained that any high-end audio system starts with the room, and room acoustics are the single-most important “component” therein (Planars… The room is the enclosure and In a nutshell, the big Maggies (3.7Rs) are a fantastic speaker, but are very dependent upon room acoustics).   I’ve met many listeners who seem content to listen to audiophile quality music on headphones but, much to the chagrin of my neighbors, I’ve never been one of them.

Unfortunately these Stax didn’t change my mind.  No matter how you slice it there is absolutely no “sound stage” with headphones.  They simply can’t project a stereo image in front of the listener wearing them so all the “imaging” happens between your ears and it feels and sounds like that.  Not to mention that they are never gonna vibrate your listening chair.

Filling a room with music is a double-edged sword, in that room acoustics can very dramatically enhance or detract from the listening experience.  But when properly set up nothing beats it.  I can only speculate that those who prefer headphones likely have nearly impossible rooms to work with (which almost none are if loudspeakers are selected for the room – Why do speakers need to be matched to room acoustics?…) or their systems aren’t set up to take advantage of the room acoustics.

Another detracting factor of listening to music on headphones is the far greater potential for hearing damage, especially with an electrostatic version such as the Stax.  It’s far easier to exceed the threshold to try to get better quality out of them.  I noticed my ears ringing after a short session of listening to them at what I considered moderate listening levels by loudspeaker standards and haven’t worn them since.  Try as I may, since it would be far more convenient with headphones, I’d rather just wait for opportune times to sit down in front of my loudspeakers.

 

It’s all about reducing mass for the transducers

When you think about it, it’s just common sense.  A low mass phono cartridge is going to track the nuances and subtle but rapid transient changes of a record groove more nimbly and with greater aplomb than one that is burdened with the task of throwing extra weight around.  That’s the whole idea behind moving coil cartridges (which are universally recognized for their phenomenal transient response), reduce the moving weight by putting the coils rather than the magnets on the end of the stylus cantilever since their mass is so much lower (The formidable Denon 103 vs. 103R low output moving coil phono cartridges – is there really a difference?…).  It’s the same with almost any high performance gear that requires fast response, from race car suspensions to avionics – the objective is to lower moving mass.

But listening to music is far more subjective than checking lap times on a race track, so some will prefer the sound characteristics of slower moving traditional speaker drivers and/or phono cartridges, even though their “performance” is hindered by their (quite literally) massive designs.  I’ll say one thing though, the first time you hear familiar music reproduced with low mass transducers (i.e a moving coil phono cartridge well matched with a pair of planar loudspeakers) will be revelatory and you will likely fall completely in love or be utterly disappointed.  It’s one of those classic love/hate scenarios.  Why?  Because the very thing that makes these speaker drivers  perform so well at high frequencies is their achilles heel for low frequencies (a low mass phono cartridge is typically good for the full frequency range, however).  So let’s look at the physics involved in low-mass loudspeaker designs.

Ribbon tweeter transducers are the very lowest mass and their thickness is measured as low as 4 microns, but their implementation is limited to high frequencies.  Electrostatic membranes come in a close second and are typically 10 to 20 microns thick (those manufactured by Martin Logan are 12 microns), and quasi-ribbon membranes are a distant third at around 500 microns (or 0.5 mm).  To put these numbers in perspective, the thickness of a typical human hair varies from around 50 to 120 microns and averages in around 100 microns.  Let’s look at each type of transducer separately.

Ribbon tweeter transducers:
A ribbon tweeter uses a very thin membrane suspended in a powerful magnetic field to reproduce high frequencies.  In their purest form, the electrical properties of the membrane itself suffice, such as when aluminum is utilized.  Other forms use metalized plastic film, where a very thin deposition of conductive material is applied to create a planar voice coil (though it’s not a coil at all, but rather evenly deposited over the entire membrane).  Ribbon tweeters are extrodinarily accurate but also are very limited in frequency response.

Being so thin, they are also extremely fragile.  Not such an issue with the small and enclosed traditional ribbon tweeter.  But with the revolutionary 55″ long Magnepan ribbon tweeter, just dropping them flat on the floor will rupture the membrane, as will vacuuming the Maggies cloth cover, or even leaving a door to your listening room open on a windy day.  Fortunately, the membrane itself is user-replacable at nominal cost (although not covered under warranty).

Many speaker manufacturers have experimented with arrays of ribbon tweeters in an attempt to create a larger line source and therefore overcome their individual limitations.  The monsterous Infinity IRS (thankfully short for “Infinity Reference Standard”) with it’s elaborate arrays of EMITs (their marketing jargon for ribbon tweeters)  comes to mind as a good example, but at nearly eight feet tall and with two separate cabinets per channel they are far from practical for most homes (see photo below).

Infinity IRS

Electrostatic transducers:
Electrostatic loudspeakers (ESLs) use a transducer that consists of an utra-thin acoustic membranes charged to several thousand volts off wall current through a step-up transformer.  This membrane is suspended between two stators that are fed from the power amplifier output via another step-up transformer connected in the signal path.

The ESL design has been around for decades.  Anyone who has heard of (or heard) the Quad ESL that originated in the 1950s will also remember what a breakthrough that loudspeaker was.  It brought ESL technology into a workable, (almost) full range speaker for the first time.  Although it was severely handicapped in many respects, it offered up sonic goods that were unprecedented and put ESL technology firmly on the audiophile map.  Many companies followed suit, Apogee being one of the main early players, but most came and went.  When Martin Logan showed up on the scene they brought a combination of technical innovation and fiscal staying power that ensured the technology persevered.  In 1986 Martin Logan offered up the very well received CLS (Curvilinear Line Source) model.  Their large, curved panels effectively solved three issues with ESLs – beaming from a line source creating a very small “sweet spot” (i.e. listening position), dipolar radiation canceling out lower frequencies as they pass around the side edges of the panel, and limited frequency response (their specifications claim the CLS goes down to 45 Hz).

These design precepts continue unchanged in Martin Logan speakers to this day, but very early on they went the path of hybrid speakers to deliver the bass response most listeners demanded.  Perhaps the most successful ESLs of all time was the Martin Logan Sequel II, which was featured at the end of the movie “The Italian Job” and made frequent appearances in the popular TV shows “Sienfield”, “Friends”, and others.  I owned a pair of these for around six years from the late 1980s to the early 1990s and I can tell you from direct experience that it’s weak point was the crossover between the ESL panels and the traditional bass drivers (a weakness that Magnepans don’t suffer from since their quasi-ribbon drivers are full range – more on that later).  I tried everything including massive amounts of power bi-amping them and never got what I considered to be satisfactory results and ultimately sold them (with the power amplifiers).  Having said that, it was the late 1908s and unfortunately the era of CDs so they never had a fair chance given they were playing crappy 44.1k/16 bit music (The “Dark Ages” of High End Audio).  But, I’ve been recently helping a friend in San Francisco set up his system with a pair of Martin Logan Ascents and I’m still not impressed, even with high definition digital sources such as SACDs. No matter how much we tweak them, bi-amp them, reposition them (and he’s got a fantastic room), I am still left feeling something lacking when I sit down and listen.  And Matin Logan’s latest no-holds-barred $80k flagship Neolith model wins the ugly duckling award, at least to my taste, see photo below (the WAF must be off the charts on this one).

Neolith-I

Quasi-ribbon transducers:
The quasi-ribbon transducer is one in which the membrane is overlaid with wire and driven directly with the signal from the amplifier passing through the wire, rather than that membrane being suspended in a powerful magnetic field as with a traditional ribbon transducer.  As far as I know, Mangepan (formerly Mangeplanar) is the only one making these.  What they sacrifice in higher mass they more than compensate for in full range ability.  Magnepan loudspeakers (also know as “Maggies”) are never gonna fully satisfy rock fans, but for those who care for a wide range of music including acoustic, jazz and classical this design really delivers the goods.  Maggie’s don’t have conventional low frequency drivers (i.e. woofers) and therefore are not a hybrid design.  They are two-way or three-way speakers comprised of ribbon and quasi-ribbon transducers with very large surface areas to deliver full frequency response.  As one might expect, the bigger the panel, the lower the frequency response (i.e. more bass).  While Maggies are quite large panels, they remain relatively flat (about two inches thick) and therefore they appear more elegant to me.

irina-magneplanar-speakers

Ok… my bad, totally cheating, did you even notice the speakers?…  A more indicative photo here.

Maggie3.7R

And a photo of the Tympani ID that I owned in the late 1970s and well into the 1980s here.

Tympani1D

Maggies have been around for decades and have changed very little in their design over the years.  Original principles, refined.  They don’t suffer from the acoustic (and esthetic) limitations of hybrid designs and also don’t require step-up transformers in the signal path and/or wall current to operate.  They do have crossovers but in their higher end models these are external boxes that can be easily modified (or “hot rodded”) and they also offer true, active bi-amplification (Why bi-amping isn’t always what you may think) abilities as shipped, without modifications.  They are very dependent on room acoustics (Planars… The room is the enclosure) and fussy about positioning and require colossal amounts of quality, high current power to operate.  Even the relatively small Mangnepan MG-12 makes my high current Nak PA-7 (The Nakamichi PA-7 power amplifier) sweat, clip, and cry “uncle” in the form of thermal overload shutdown when I crank it for extended periods.  But to many audiophiles they are, and always have been, the holy grail.

In a nutshell, the big Maggies (3.7Rs) are a fantastic speaker, but are very dependent upon room acoustics

So I made a trip to Calgary to give the Mangepan 3.7Rs a listen.  The “R” stands for “ribbon tweeter panel”, indicative of high end Mangepans.  In a nutshell, the big maggies (3.7Rs) are a fantastic speaker, but wouldn’t be right for my room.

I had figured out a way to accommodate these gorgeous sounding speakers (and for some, gorgeous looking too but the WAF often factors in on these babies).  I had even 3D modeled my Canmore listening room with them in it with architecture software just to make sure they would fit.   As such, I was very excited to audition them at a high end dealer in Calgary.  But after listening to them in a room with almost exactly the same dimensions as mine in Canmore and playing around a great deal with positioning, even from what the very knowledgeable advisor thought was best, I continually felt like their performance was being compromised dramatically by being too close to the side walls of the room.  And… if you move them farther from the side walls then they are too close together, so it’s a no-win scenario.

I went in with great expectations.  Having owned a pair of Tympani 1Ds in the past, I couldn’t wait to hear the modern day equivalent, and the 3.7Rs simply fell flat on their face in those terms.  To be fair, I only ever listened to my 1Ds with a very high end vinyl front end, but none-the-less, these just didn’t make it worth compromising my room only to have my room compromise their sound quality.  As I’ve always said, the room is the most important component in any audio system, and this proved true once again.

The dealer had nothing but high end turntables in their main listening room (I counted a total of nine set up to demo), and he personally shared my love for the Denon 103R phono cartridge and it’s what he runs at home.  But ironically the room that I wanted to listen to the Maggies in, since it has very similar dimensions to mine, only had a SACD player.  So that’s what I brought with me for listening tests, three of my favorite reference SACDs.  I did a total of 4 listening sessions, as follows:

Listening Session Number One – Magnepan 1.7s.  I basically walked out right away and said, “this just isn’t doing it for me”.  Like i said, I went in with high expectations from past Magnaplanars owned.

Listening Session Number Two – 3.7Rs.  Those ribbons are simply amazing.  So accurate.  But, unforgiving almost to a fault.  You better up your game in all respects if you’re gonna own these babies otherwise they will be a constant reminder of what else is amiss in your signal path.  And  i suspect they would be far better paired with a tube pre-amp.  Overall, they are very impressive but not the speaker for me at this stage of the game and they never did their sound staging properly since the room was too small – so obviously not the right speaker for my listening room in Canmore.  While the bass isn’t pronounced I found it satisfying for my listening taste.  Though not as satisfying as my Kef 104/2s which are only rated to go down to 50 Hz (the 3.7Rs are rated to go down to 40 Hz), but sound much tighter due to the very well engineered cabinet resonance that obviously doesn’t exist with the 3.7Rs since there is no cabinet to resonate (Planars… The room is the enclosure).  Bass response has never been a strong suit of Maggies, but I do remember having more bass with my Tympani 1Ds from 35 years ago.  But that just makes sense, the 1Ds had more planar surface area dedicated to bass response (they had three panels in total vs. the two of the 3.7Rs).

The original Mangepan Tympani 1D.  A revolutionary loudspeaker to say the least.
The original Mangepan Tympani 1D. A revolutionary loudspeaker to say the least.

Listening Session Number Three –  A little disappointed, I suggested  we try the Magnepan MG-12’s.  These weren’t on my hit list, but I was 0 for 2 so far and figured, “you never know…”   Bingo!  All of a sudden I was immersed in all that famous sound staging and Maggie sound I was craving.  These were the right Maggie for the room dimensions, period.  Could I hear what the ribbon’s on the 3.7Rs were capable of?…  Sure!  Did it make for a better sounding experience overall with the room (relatively small) and source (SACD so digital) I was auditioning?  No, I’d venture to say just the opposite.

Listening Session Number Four – I gave the 3.7Rs one more listen just to be sure.  I really did want to love them and had high expectations, and I could tweak away to my hearts content with their external crossovers allowing me to passively or actively bi-amp their panels.  But the answer remained the same.  I think if I were a classical music buff the outcome very well may have been different due to their extraordinary dynamic range.  But, much as I like listening to classical music on occasion, I am not and likely never will be a classical music buff.  And no matter what music you listen to, I’d venture to say the 3.7s are too big for my Canmore listening room (and the room I auditioned them in).  Or perhaps better to say the room is too small for them to breathe.

So I walked in to that Calgary high end audio store wanting to love the $6K 3.7Rs and walked out loving the $1.3k MG-12s.  Sometimes less is more and it just goes to show, you’ve gotta audition gear live rather than trust what you read.  And when auditioning speakers you’ve gotta do so in a room very similar to the one at home you will be listening to them in.  Or better still, take them home on a trail basis.

Banana plugs or spades for speaker cables?

So I’m gonna come straight out the gate by saying that I’ve never done any listening tests on this one, and I probably never will.  Why?  Because I’ve used both for so many years and never noticed the slightest difference.  So my discussions herein are based upon theory rather than empirical discoveries.  And, to further cloud the discussion, manufacturers of both power amplifiers and speakers that are some of the best I’ve ever heard seem to differ on this subject, although most offer both options.  Magnepan would be the most notable exception, offering only banana plug connections for their planar speakers (in a nutshell, the big maggies (3.7Rs) are a fantastic speaker, but wouldn’t be right for my room.)  The folks at Zu Audio (The quest for some bang for the buck in interconnects and speaker cables) favor spade connections whenever possible, and I agree with them in theory.

This goes back to physics 101 in regard to contact resistance and it’s relation to the surface area as well as the pressure imparted upon the mechanical junction.  If you look at the photo of a banana plug termination you will notice that it likely offers less surface area than that of one made with a spade.  But more importantly, the pressure of the junction is limited to the amount of outward force created by the spring effect of the bent metal, whereas with spades one can impart far more pressure on the junction, which can offer higher conductance.  Also, many banana plugs are user-installed with some sort of a screw on system that is highly prone to error, meaning you could have 12 AWG wire with a weak link of just a few strands at the banana plug.  By contrast most spade terminations, even when user installed, are soldered.

In either case, the most important thing is full contact for the termination method used which is ideally made by cold forging, a method which pretty much rules out user installation.  Second best would be a high quality solder connection (just like inside the amplifiers themselves), and a distant third would be user-installed mechanical connection, such as spades with screws on them or banana plugs with screw down connections on the wire.  In fact, if it would be far better not to terminate your wire at all and properly connect the bare wire than to add an inferior user-installed banana or spade termination.

Some purists go so far as to eliminate the mechanical interface altogether by soldering their speaker wires directly to the amplifier outputs, but this is definitely on the extreme side and inconvenient to say the least.  I say any of the above methods can offer comparable sound quality, as long as care is taken to maximize contact area and pressure and all mechanical contacts are kept clean of course.

A free upgrade for your planar speakers

Planar speaker (these are Maggie’s but the same applies for Martin Logan’s and others) like to have lots of room around them and nothing in between to interfere with their soundstage.  If you have a big screen planted the same distance from the listening position as the speakers are, it’s over – for 2 channel audio sound staging any way, 5.1 music and home theatre is still cool (The most obvious difference between 2 channel audio and 5.1 home theatre).

For 2 channel sound staging, I suggest changing the location of the big screen from  front and centre in the middle of the speakers imaging plane (a very common mishap) in favour of a wall mounted one behind them that could also possibly be covered in fabrics curtains (or not, I’d try both ways).  With two mono block amplifiers, it’s possible to get your power amps out of the way as well.

I’ve applied these concepts with my room and Maggie’s in Canada to simply amazing effect.  The sound staging is out of this world.  it took a great deal of trial and error to get it there but so worth it!  No amount of $$$ spent on amps, sources, or other such things will make that happen without the room placement and treatments being dialed in first.

And…  The room doesn’t have to be dedicated and/or unfurnished to get there, it’s just easier that way.  Moving a little furniture around and speaker placement got the effect I was looking for in my very compact room in Canada. Ok… Moving a lot of furniture around!

But I already have in-wall speakers and a built in audio system, what do I do?

so your dilemma is exactly what i’m starting a consulting business to help people with.
the short answer to your question is yes, you need a dedicated system for quality 2 channel sound (i.e vinyl, though it’s not limited to just that)
in order to advise further, i’d need to see your room.  that’s where it all starts, with the room.  and that’s where i come into the picture.  i can’t name one high end audio dealer that approaches it that way, visit the customer’s room first.  they all just have their rooms and what the equipment can do in the showroom.  these are dealers who typically sell systems from $10K to $100k.
in all honesty, i don’t know how they can do it.  either they don’t know or don’t care but it’s simply impossible to advise someone on audio gear without starting with room acoustics and in order to do that you need to see and hear the room

Planars… The room is the enclosure

Maggies often love acoustically reflective surfaces behind them for imaging, so the glass might work to benefit them in your LR.  i have the perfect scenario for my rear wall for my Maggies in Canada, three acoustically reflective surfaces in an octagonal configuration (in other words a bay window).  see the rendering i sent previously.

My room acoustics here on Maui are my big limiting factor and I can’t get planers like Maggie’s to work here. They work in my room in Canada, but not the big Maggie’s.

On the other hand my Kefs are awesome here in Maui but likely wouldn’t sound nearly as good in my room in Canada that has very different dimensions and surfaces.  Very different indeed.

 

more later…

Why do my speakers have spiked feet?

Spikes are clearly acoustical couplers (that’s why you want them on the bottom of your speakers), so why would I want to couple the upper platform to my TT you may ask?…  Well, by doing so I effectively increase the mass of my TT plinth by 9 pounds whilst the entire thing is isolated.  And, by virtue of their design they act as mechanical diodes (one way valves) to remove any mechanical vibrations from my TT motor away from my stylus (page 406).

The acoustic adventures continue…

 

More later…

Self Powered Speakers

PurityToIPODwho better to design an amp perfectly to drive their speakers than the speaker manufacture themselves.  i had some self-powered bookshelf speakers back in the day that were simply amazing!  the beauty would be simplicity and cost savings, the down side if if the amp blows or the speaker element blows, you gotta fix it or you loose both your speakers and your amps at the same time.

More on self powered speakers later…

The most obvious difference between 2 channel audio and 5.1 home theatre.

My experience with surround sound (usually found in audio systems for home theatre) is that it relies greatly on the centre speaker to create the sound stage.  This is obvious for movie sound tracks, but also prevalent on surround sound music mixes, such as those found on SACDs and DVD-As.One of the real benefits of  digital surround sound is that it can combine both the highest digital quality available along with amazing 5.1 surround sound mixes.  A win/win for anyone who has longed for more than just two channels to present the music with.

But traditional ESLs (electrostatic loudspeakers), such as the venerable Martin Logan Sequels and the Sequel IIs, were a product  of 2 channel stereo sound reproduction.  They were never intended to be part of surround sound speaker set.  Not that they wouldn’t be great at it, just that the nuances of the sound stage they have been designed to create would certainly be lost once you throw the centre speaker into the mix, which pretty much destroys any intended 2 channel sound stage anyway.

This isn’t all cons, however.  In very difficult rooms or where the rooms esthetics trump the ideal speaker placement, a centre channel can serve to save the day.  But with good room acoustics and  a reasonable option of placements for ESLs, a pure two channel signal path will reproduce a more engaging and intimate soundstage every time.

Horizontal bi-amping with non-matching amplifiers

Wiring for horizontal bi-amplification
Wiring for horizontal bi-amplification

Horizontal Passive Bi-Amplification
Horizontal bi-amping allows you to use two different types,
models or brands of amplifiers (i.e. tubes on top, transistor
on the bottom). However, we recommend that you use
two identical amplifiers (i.e. same brand and model).
If you must use two different amplifiers, it is essential that
they have the same gain or that one of the two have adjustable
gain so that you can match their gain characteristics.
If the amplifiers of choice do not have the same gain
characteristics, then a sonic imbalance will occur.

For non-matching amplifiers:

since the loads your adcoms present to the Onkyo are 50K ohm and 100K ohm, which should present a load 33.333K ohm load to your pre-amp, which should be easily driven by it, assuming the output impedance of 470 ohms specified in the manual for your record outputs (rec out) on your Onkyo is also put out on your pre-outs.  It doesn’t specify for the pre-out, so fingers crossed that it’s about the same as your record outs.  the quality of tour interconnect cables and splitters will likely have a great effect on impedance than your mismatched amps.

see this link for how to calculate impudence for dissimilar loads wired in parallel (this is in a perfect world. it’s actually WAY more complicated than that, but this is good enough for what we are up to):

http://www.sengpielaudio.com/calculator-paralresist.htm

 

ohms and calculations aside.  think of it in these simple terms…

you will be splitting the signal from your Onkyo L and R front pre outputs and sending it to two amps instead of just one.  so think of it as now “driving” two amps instead of just one.  this puts a far greater load on your pre-amp.  most audiophile quality pre-amps are designed with this in mind.  but AVR receivers with pre-outs as an add-on or even an after-thought…  not so much.  don’t get me wrong, i think your Onkyo will drive your amps just fine.  but we want to do everything we can to make it easier.  this includes:

– high quality splitters
– high quality and as short as possible interconnects (that’s why i like the stubby splitters, why add more cable into the equation if you don’t need to)

to insure against any hum, you will want to place your pre-amp (Onkyo) at least 6” away from your adcoms, preferably on a different shelf.  if you can still get away with 3’ interconnects, that would be best.

More later…

Why bi-amping isn’t always what you may think

BiAmping

Bi-amping used to be the sole providence of high end audio.  I’m therefore suprized that many modern mid-fi speakers have the ability at all.  But, as long as it’s there why not play around with  and see if it makes any difference.  Most modern, higher end 7.1 AVRs also have the ability to utilize the “surround back” speakers to another zone or to bi-amping your front speakers if you like.

That said, we are still talking about a very different version of bi-amping from what i knew it to be in the 1970s, i.e. passive rather than active.  The good news is that passively bi-amping just requires removing jumpers (or “bridging plate”) and hooking up directly to the binding posts on the speakers and let’s the speaker manufacturer decide what happens from there.  Less control, but also less ways to screw it up if the listener doesn’t have knowledge of speaker crossover networks.

Active crossovers (XOs) require some basic knowledge of speaker design, crossover designs, and the limitations of the individual drivers.  I built up a small pair of speakers in the 70s with Kef B110 bass drivers and T27 tweeters.  I was building off a schematic but tweaked the parts of the passive crossover network with better quality than what the manufacturer (they were Rodger’s LS35A’s) provided and they sounded AMAZING and i saved a ton of $$$ by buying the drivers separately and building them myself.  As a side note, those 70s speakers (from the manufacturer, not my home-made version) have become highly collectable and I’ve seen them advertised for up to 10 times their original selling price of $400, which was high  at the time.

 

Subwoofers

SubwooferCutAway

Matching subs to speakers has a lot of chatter on the forums since it is requires the listener to get involved to get it to sound right.   Often subs are matched to front speakers of a different manufacture, which means the speaker designers aren’t in the loop as to how things go.

Ultimately, it is up to the listener to “tune” the sub which would be a difficult task if you try to do it technically, with cross-over curves and such.  but… it’s really easy to do for a trained ear when you know what to listen for.  I just set the phase correctly (immediately obvious when you toggle the switch) then play with the volume and low pass cross-over setting until it sounds right.  I often adjust it differently for different sources.

thought i’d elaborate on the “.1” of 5.1” sound.  (since it comes up so often by the techies).

firstly, it puts the speaker designer out of the loop, so the user needs to pay close attention to how they mix and match subs to the rest of the speaker system.

so…  when you are talking about digital audio outputs (HDMI, digi Coax, Optical), which almost everyone is these days, what happens to the .1 becomes a matter of great debate.  The techies love this kind of stuff, and spend more time dwelling on it than actually listening to music and/or watching movies.

but… when we are talking about analog audio 5.1 outputs, such as is the case with SACDs (some at least, see below), the decision as to what is going to your subwoofer has already been made when the audio was mixed.  the sound engineer doing the recording did it, and almost certainly did it far better than any of the digi techies could ever dream of.  of course, you still need to tune your subwoofer to your system, but what content it is getting is nice and clearly decided for you.

that’s why i suggested you try your ML’s both ways, with and w/o the sub.  To understand why, consider that there are three types of SACDs:
1. SHM Stereo only (like my Japanese imports)
2. Hybrids that have a “Redbook” CD layer (44.1 kHz sampling) and an 2 channel SACD layer (like all of the MFSL Original Master recordings)
3. Triple Layer that have a Redbook CD layer, 2 channel layer, and a 5.1 surround mix layer (these are the ones that tend to become collectable when they go OPP since the only version of that 5.1 mix that exists in this universe is on them)

I think when you play the 2 channel only versions, it’s quite possibly they will sound better by letting the MLs, bi-amped, handle the entire job by themselves.  Otherwise, you need to get in the middle and decide how you want the subwoofer to behave, crossover, etc for the 2 channel sound.

But.. when you play the 5.1 mixes, the sound engineer (but this is beyond engineering, and an art in of itself) in the mixing room will have decided what content goes to the sub already.  you just hook it up, tune it a bit according to the type of sub it is and personal tastes, and let the magic happen 🙂

having said all this.  i think it’s time to just have some fun listening to your music collection again.  you are already way ahead of the game just as things are now.  i just LOVE listening to music and the real pleasure that I get from adding of upgrading gear is not from the technical aspects, but from how i can rediscover my music collection when i do.  for example. i’ll try a different phono cartridge and… assuming i like it better than what i had, want to listen to most of my music again before i change a single other thing.

all your CDs are gonna be a fun experience in rediscovery just based on how things are now. enjoy getting to know your music again.  or for the first time.  you could spend months just rediscovering your existing music collection.  it’s really fun to pick up the differences and develop your personal tastes along the way.  then you will really pick up some of the other improvements when you add an Oppo (even just to your existing CD collection) or start picking up a few SACDs…