On Elephants and Listening Trials...

By Bryan Geyer

On Elephants in the Room...
Two of the most notable absurdities in home audio share a common fault: They’re grossly oversized and/or overweight for any normally dimensioned residential living room. You’d really have to live in Hearst Castle in order to claim that the use of these components is sensible or appropriate. I’m talking about (a) those monster (100 pounds apiece) power amplifiers that cost $5k-$10k ea., and (b) those towering pairs of planar electrostatic loudspeakers that cost a bundle—despite their poor efficiency, inconsistent performance (always subject to numerous ambient variables), and comparatively (to dynamic/magnetic drivers) crummy reliability.

It’s very likely that the era of the 100 pound power amplifiers is now ending, and that all such boat anchors will eventually become obscure relics. Future hi-end speaker systems just won’t be built that way. The old concept wherein one big power amplifier is used to feed a passive crossover network that’s in series with all drivers is truly archaic. The modern trend is to use active line-level crossovers that feed multiple power amplifiers. Those bandpass amplifiers can then directly drive the separate segments of a multi-driver speaker system, and do so with precise accuracy, better damping, and fully independent gain control. This method presents vital convenience and flexibility advantages, since each amplifier’s response can then be optimized as needed to assist in attaining a desired room response (EQ) profile. The use of one big power amplifier/channel was a natural and practical solution that fit the past, but new size and integration breakthroughs have now made it preferable to consider this multi-amplifier alternative. Top quality hi-end systems will embrace this concept. In many cases, it’s likely that some of these bandpass power amplifiers will be fully integrated with their designated driver, and buried inside the speaker enclosure. In those instances, compact class D power amplifiers will become the preferred tool, just as with the self-powered subwoofers that are so popular today.

Big planar panel electrostatic loudspeakers (see photo) will soon become extinct unless there’s substantial design improvement. In general, the existing electrostatic means for implementing planar propagation is just too “buggy” to sustain consistent, reliable performance. Such speakers are sensitive to variations in ambient temperature, humidity, and altitude (moon phase too?). They’re  easily damaged, inefficient, and vulnerable when pushed to sustain high sound pressure levels. They’re also costly to make, ship, and sell. Robust redesign seems essential. It’s possible that new materials (such as graphene) might spur this progression. Regardless, dynamic/magnetic loudspeaker design has steadily evolved, and the focused propagation advantage that’s attributed to planar speakers seems less distinctive now than in prior decades. Barring a dramatic upgrade, I see a dim future for those big electrostatic panels that resemble room divider screens; they’re looking obsolescent. That said, the large planar model 10e ESL from Sanders Sound Systems looks exceptional. It’s an elegant “no compromise” product (price with designated Magtech Stereo amp ~ $22.5k) that’s aimed to satisfy the pride of its creator and the respect of the ultra-niche market that it serves. This looks to be a fine example at what’s possible when good engineering meets a targeted (lots of listening space + gobs of money) consumer. That’s a convergence that I’ve never experienced, but maybe it fits your profile.

And On Listening Trials…
If you want to conduct a listening trial face-off between your regular power amplifier and another amp that’s on loan from a friend or dealer, do make certain that you compare the two amplifiers fairly, under identical test conditions. Of course, that means using the same cable connections, same loudspeakers, same room setup, and the same listening seat, but don’t automatically use the same position on your master volume attenuator. Be aware that the internal voltage gain of various power amplifiers will routinely vary by design; they commonly range between ~ +23dB and +29dB. You can research differences in gain by checking the respective amplifiers’ specifications; they’re generally printed on the last page of the related instruction booklet, as well as appearing on makers’ websites. One can easily compensate for a gain difference by adjusting the main volume attenuator to assure that the sound pressure level (SPL) at the listening position is precisely equal for all amplifiers under test.* The incoming source signal’s amplitude range is normally sufficient to accommodate any adjustment of the attenuator that might be needed to set an accurate SPL match at any desired listening level.

To accurately monitor the SPL matching, use a basic SPL meter (https://www.bhphotovideo.com/c/product/1149079-REG/nady_dsm_1x_digital_spl_meter.html), and position it (mounted on a tripod, or on a lighting or microphone stand) at the listening site. Use a fixed frequency sine wave source as the test signal; something between ~ 400 Hz and ~ 800 Hz is generally best. Match carefully! A difference of as little as ± 0.5 dB in SPL could unfairly bias your judgment, and the loudest output will always win, regardless of any other aural distinction that might seem evident.

Given modern solid-state power amplifier design, and assuming that such amplifiers are not driven into clipping, and that their sound pressure levels are accurately matched, you will probably conclude that there’s zero audible difference between the contending products. This expectation does not apply if the on-loan amplifier is an appealing new component that you’ve recently considered buying. In that instance, the on-loan amplifier will always sound spectacularly superior; it will “blow away” the old amp.

BG (September 2019)

*If your master stereo volume attenuator has calibrated stepped detents you might find it difficult to achieve a setting that yields a precise SPL match. In that event, check the rear panel of both power amplifiers. Many amps include a pair of rotary potentiometers, installed at the input stage, to facilitate balance adjustment of the incoming left/right stereo source signals. You can use these pots as supplementary volume controls to trim the SPL output in small increments that are finer than a stepped attenuator might resolve. Just remember to return these pots to their previous positions (generally full up) when your testing trial is finished.

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Meet the Staff

Meet the Staff
John J. Puccio, Editor, Publisher, Reviewer

Understand, I'm just an everyday guy reacting to something I love. And I've been doing it for a very long time, my appreciation for classical music starting with the musical excerpts on The Big John and Sparkie radio show in the early Fifties and the purchase of my first recording, The 101 Strings Play the Classics, around 1956. In the late Sixties I began teaching high school English and Film Studies as well as becoming interested in hi-fi, my audio ambitions graduating me from a pair of AR-3 speakers to the Fulton J's recommended by The Stereophile's J. Gordon Holt. In the early Seventies, I began writing for a number of audio magazines, including Audio Excellence, Audio Forum, The Boston Audio Society Speaker, The American Record Guide, and from 1976 until 2008, The $ensible Sound, for which I served as Classical Music Editor.

Today, I'm retired from teaching and use a pair of bi-amped VMPS RM40s loudspeakers for my listening. In addition to writing the Classical Candor blog, I served as the Movie Review Editor for the Web site Movie Metropolis (formerly DVDTown) from 1997-2013. Music and movies. Life couldn't be better.
Karl W. Nehring, Contributing Reviewer

For more than 20 years I was the editor of The $ensible Sound magazine and a regular contributor to its classical review pages. I would not presume to present myself as some sort of expert on music, but I have a deep love for and appreciation of many types of music, "classical" especially, and have listened to thousands of recordings over the years, many of which still line the walls of my listening room (and occasionally spill onto the furniture and floor, much to the chagrin of my long-suffering wife). I have always taken the approach as a reviewer that what I am trying to do is simply to point out to readers that I have come across a recording that I have found of interest, a recording that I think they might appreciate my having pointed out to them. I suppose that sounds a bit simple-minded, but I know I appreciate reading reviews by others that do the same for me -- point out recordings that I think I might enjoy.

For readers who might be wondering about what kind of system I am using to do my listening, I should probably point out that I do a LOT of music listening and employ a variety of means to do so in a variety of environments, as I would imagine many music lovers also do. Starting at the more grandiose end of the scale, the system in which I do my most serious listening comprises an Onkyo C-7030 CD player, Legacy Audio StreamLine preamplifier, Legacy Audio PowerBloc2 amplifier, and a pair of Legacy Audio Focus SE speakers augmented by a Legacy Point One subwoofer. I also do a lot of listening while driving in my 2016 Acura RDX with its nice-sounding ELS Studio sound system through which I play CDs (the ones I especially like I rip to the Acura's hard drive so that I can listen to them whenever I want) or stream music through the system using my LG G7 ThinQ cell phone, which features surprisingly sophisticated audio circuitry. For more casual listening at home when I am not in my listening room, I often stream music through the phone into a Vizio soundbar system that has remarkably nice sound for such a diminutive physical presence. And finally, at the least grandiose end of the scale, I have an Ultimate Ears Wonderboom Bluetooth speaker for those occasions where I am somewhere by myself without a sound system but in desperate need of a musical fix. I just can't imagine life without music and I am humbly grateful for the technology that enables us to enjoy it in so many wonderful ways.
Bryan Geyer, Technical Analyst

I initially embraced classical music in 1954 when I mistuned my car radio and heard the Heifetz recording of Mendelssohn's Violin Concerto. That inspired me to board the new "hi-fi" DIY bandwagon. In 1957 I joined one of the pioneer semiconductor makers and spent the next 32 years marketing transistors and microcircuits to military contractors. Home audio DIY projects remained a personal passion until 1989 when we created our own new photography equipment company. I later (2012) revived my interest in two channel audio when we "downsized" our life and determined that mini-monitors + paired subwoofers were a great way to mate fine music with the space constraints of condo living.

Visitors that view my technical papers on this site may wonder why they appear here, rather than on a site that features audio equipment reviews. My reason is that I tried the latter, and prefer to publish for people who actually want to listen to music; not to equipment. My focus is in describing what's technically beneficial to assure that the sound of the system will accurately replicate the source input signal (i. e. exhibit high accuracy) without inordinate cost and complexity. Conversely, most of the audiophiles of today strive to achieve sound that's euphonic, i.e. be personally satisfying. In essence, audiophiles seek sound that's consistent with their desire; the music is simply a test signal.

Mission Statement

It is the goal of Classical Candor to promote the enjoyment of classical music. Other forms of music come and go--minuets, waltzes, ragtime, blues, jazz, bebop, country-western, rock-'n'-roll, heavy metal, rap, and the rest--but classical music has been around for hundreds of years and will continue to be around for hundreds more. It's no accident that every major city in the world has one or more symphony orchestras.

When I was young, I heard it said that only intellectuals could appreciate classical music, that it required dedicated concentration to appreciate. Nonsense. I'm no intellectual, and I've always loved classical music. Anyone who's ever seen and enjoyed Disney's Fantasia or a Looney Tunes cartoon playing Rossini's William Tell Overture or Liszt's Hungarian Rhapsody No. 2 can attest to the power and joy of classical music, and that's just about everybody.

So, if Classical Candor can expand one's awareness of classical music and bring more joy to one's life, more power to it. It's done its job. --John J. Puccio

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"Their Master's Voice" by Michael Sowa

"Their Master's Voice" by Michael Sowa