Disclaimer: I first met Roger many years ago, when he was still in Georgia. He now lives a couple of hours away but I have never been to visit, alas. I have long respected he and his speakers though he has his share of detractors. Note the interview itself is several years old and was discussed at length on various fora at the time.
I'll paste my comments into the text FWIWFM.
Challenge to y'all: I will list what I think are the most interesting claims he makes in the interview. Then I will ask you to indicate whether you agree or not - yes (Y), no (N), don't know (DK). And possibly motivate why. I will start myself to get the discussion going. Please read the interview first though!
1) "Roger Sanders makes the best loudspeakers in the world".
Doesn't every designer feel they make the best? ESLs in general are a special breed; you like them or not, ditto most planar dipoles. So I'd agree for some, disagree for others, but in general would not personally claim "best" at anything.
2) "A S.O.T.A. speaker must use an electrostatic midrange".
The reason he provides: "The reason that electrostatic speakers are so good is that they are the only type of midrange driver that has essentially no moving mass. Magnetic speakers simply cannot match the performance of electrostatics in the midrange because they are heavy so cannot be accelerated quickly and accurately at treble frequencies"
Well, there is mass, but it is driven across the diaphragm so creates a much different wavefront than conventional speaker drivers. Conventional speakers are sized and designed for the frequency ranges they cover. I personally tend to think the lack of multiple drivers and crossover issues in the midrange is part of the ESL magic. Some conventional speakers do very well at that as well; to my ears, my Revels are among the best I have heard. Some others, even high-priced models, seem to have hiccups in the midrange
to me.
3) "Magnetic woofers have many problems with their enclosures that cause them to produce with a lot of overshoot and ringing that makes it impossible for them to integrate well with a massless electrostatic speaker".
The enclosure argument has been around a long time, but he does in fact use a magnetic woofer (transmission line) but with a lower crossover than most other ESLs. I think that is part of the reason I have preferred Sanders over
some other ESLs. But, I have noticed that woofer integration has gotten a lot better over the years for things like Martin Logan ESL hybrids. The overshoot and ringing has to do with more than just the cabinet, of course, and overshoot and ringing in any design is undesirable for accuracy.
4) "The solution is to use a transmission line enclosure system to virtually eliminate overshoot and ringing in the woofer".
Along with other design features, natch, like proper enclosure/driver/amplifier integration.
5) "No speaker can be considered S.O.T.A. if it uses a passive crossover. All speakers will perform better when driven by active crossovers and individual amplifiers for each of their drivers".
Toughie. Some speaker do very well with passive crossovers, and a poorly-implemented active crossover can be a Bad Thing. The passive crossover in some designs improves matching to the amplifier, but the complexity and losses in a passive design means a good active design should work better most of the time IMO.
6) "Loudspeakers are the most important component in your system. All are seriously flawed. You should put most of your money and effort into getting the best ones you can".
Although we could debate the word "seriously" I tend to agree with this.
7) "Rooms interact with loudspeakers to seriously degrade the sound. It is essential to deal with this problem using proper positioning, room treatment, and DSP".
Yes, room interaction is a pain, but DSP is not a complete panacea, treatments can be over- or under-done, and positioning is sometimes less than ideal due to other considerations. I suspect most of us live fine with less than ideal rooms. I do question the validity of some reviews after seeing pictures of the reviewer's room; the claim is they know what it sounds like so can render accurate judgement, but being from Missouri I always think "show me".
8) "The distortion from a Class A amplifier is no lower than in a Class AB amplifier. So there is absolutely no reason to use Class A anymore"
In fact many pure class-A amplifiers have higher distortion, higher noise, higher output impedance, and lower stability compared to class AB amplifiers. Trades always.
9) "I do not consider switch mode (Class D) amplifiers to be high fidelity devices". (for full bandwith)
Reason: "This is because they do not have linear frequency response. Their high frequency response depends on the character of the load (the loudspeaker). Therefore they must be specifically adjusted to your specific speaker to have linear frequency response. Because woofers do not reproduce high frequencies, switch mode amps are excellent for driving woofers (which require a lot of power)".
Largely superseded by advances in both circuit topology and better devices available these days IMO.
10) "Digital recording media [and digital playback] is flawless. By comparison, analog is very poor".
Again as an engineer I rarely if ever speak in absolutes. I do not think digital is flawless, but much of the problems are due to the recording and mastering process rather than fundamental digital flaws. OTOH read some of Amir's reviews and you can see that implementation matters. Technically analog is usually poorer but in some cases the added artifacts sound more pleasing to folk than absolute acccuracy to the source. A preference vs. reference debate.
11) "As long as you use a data rate of 192 KBPS or higher, you cannot hear any difference between an MP3 recording and the original source".
Not competent to say, not enough experience with MP3s.
12) "DSP systems are extremely powerful and effective tools. They can improve all audio systems and every audiophile should use them".
[Sanders uses it for crossover and speaker eq, and recommends room correction in the bass but not in higher frequencies]
And just as capable of creating a mess in the wrong hands. Again the absolute "all" is beyond what I would say, not having heard all systems.
13) "There is no such thing as too much power"
Reason: "It is easy to show that most speaker systems require about 500 watts to play musical peaks cleanly. Most audiophiles use amps with far less power. Therefore audiophiles are comparing clipping amps most of the time".
Many people jump on the amplifier bandwagon when they are only averaging a few watts if that. OTOH the dynamic range is huge and it may well be more power is useful. Clipping tends to happen only briefly so I wonder how real a problem it really is, and of course if the power exceeds the speaker's limits it does you no good. There have to be reasonable bounds.
14) "Components that meet the Basic Quality Criteria (BQC) for high fidelity sound always sound identical to each other".
He mentions this as the basic quality criteria: "1) Inaudible noise levels (a S/N of 86 dB or better is required), 2) Inaudible wow and flutter (less than 0.01%) 3) Linear frequency response across the audio bandwidth (20 Hz - 20 KHz +/- 0.1 dB), 4) Harmonic distortion of less than 1%"
Too many variables left out. What about jitter, output impedance, multitone and IMD distortion, response during clipping, etc.? Again with the "always".
15) "You must do ABX testing to obtain valid results from listening tests".
Some sort of blind testing is pretty much required; eyes are too easy to fool. But it's hard to do even when you have the skill to create a valid test, resources to implement it, and sufficient time and subjects for a credible result. It can be very revealing, and humbling, when something you "know" is proven wrong. I have had it happen both ways; when I knew I could tell a difference but could not in a DBT, and heard a difference when I was sure it would not be there. What I have found is that often enough when I hear something "new" due to some system change, going back to the old system revealed it was there all along, and I simply hadn't noticed or had forgotten.
