Revel Salon loudspeaker A Visit, Continued 2

Greenhill: How did you determine that off-axis response was so important in speaker design?

Voecks: The real breakthrough in the design of the Salon was getting a speaker measurement that correlated with double-blind listener preferences. We divided our measurements into three groups.

First was the direct sound. We measure direct sound at the listening window. This yields a curve that gives loudspeaker measurements a bad name, because it can look good with a lousy speaker. We do an average of seven measurements. That cancels out local interference that doesn't mean anything in itself. Other designers may smooth the curve so it can be legible, but that throws out important data. By taking the average over a small area, we end up with a smooth, interpretable curve. This is because the artifacts average out, without having to discard data that turn out to be important.

Second, the early reflections from nearby surfaces are measured after a slight delay—20ms. This is so early that the ear-brain system can't sort it out. The performance of the speaker 60-70 degrees off-axis needs to be included in this early-reflections measurement because it contributes to early reflections. The off-axis sounds are just as important as the on-axis. Two speakers that look the same when you measure the direct sound can look wildly different off-axis.

Third, the off-axis speaker performance contributes most to the reverberant sound. This correlates with speaker timbre, one of the most important factors in listener preferences during double-blind tests. We take 72 measurements in the "4Pi" anechoic chamber by rotating the loudspeaker on a table and varying microphone height. The listening tests conducted in the MLL enabled Floyd and the group to determine how to use these 72 measurements and weight them to generate a single curve. This generates the Calculated Perceived Response, which we call our "target." The ideal, as far as listeners go, is not a flat line. If [a loudspeaker is] set to be flat, it is perceived as overly bright. Listeners prefer the "target" to be sloping down, and report that as "neutral."

Greenhill: As the Salon's designer, you used the double-blind listening panel's preferences to confirm your design choices. Was this panel trained to a standard before these tests? If so, this would be the first use of a trained and "certified" double-blind listening panel to help a designer!

Voecks: Yes, all panel members are trained first using a computer-aided instruction course before they participate in listening tests in our MLL (footnote 2). Sean Olive, Harman's manager of subjective evaluation, explains that "the current threshold or criteria in selecting listeners on our 'expert' or 'trained' panel is that they must achieve at least 95% correct in the 6dB-resonance identification task and 85% correct in the 3dB task. Both tasks involve correctly identifying the center frequency of resonant peaks and dips of added resonances that are 2.5 octaves wide. Generally, members who meet these criteria do so after one to three training sessions that last about 30 minutes each. We have found that after five training sessions, about 20% of motivated people with normal hearing cannot meet this target and are not accepted on the panel. In addition, we do not select listeners with more than -15dB loss at any audiometric frequency, since Toole found that listeners ! with hearing losses greater than this are less consistent in their opinions compared to normal-hearing listeners."

Footnote 2: See S.E. Olive, "A Method for Training Listeners and Selecting Program Material for Listening Tests," presented at the 97th Convention of the Audio Engineering Society (November 1994). Preprint 3893 (H-5).

Ornello's picture

These abominations are some of the worst speakers i have ever heard. That they are sold, let alone that the 'manufacturer' asks $15,000 per pair for theses abominations, is an insult to the human race.

makrisd's picture

Are you experiencing hearing problems? Probably the best speakers in the world!

Ornello's picture

These abominations sound like crap. My hearing is exceptional.

Christopher's picture

@Ornello :
You must not be familiar with Harmon Audio Group's testing facilities and procedures, and, you also must not have heard these speakers working properly. Either you heard some bad quality clones, or there was something terribly wrong with some other piece of equipment in the chain, or, very bad source material.

Because not only do these speakers measure exceptionally well from an entirely objective perspective, they also have EXCELLENT sound quality both from my perspective as a person who listened to them while working for a COMPETITOR -and- from the perspective of a panel of expert trained listeners working at the parent company.

Even if these speakers did not suit your personal preference [for non-neutral sound], I don't believe you honestly could have listened to them and come away with an opinion that the were not at least "generally excellent"!

In 2003 I went to all the major high end audio boutiques in Manhattan and auditioned several of their finest (and some more modest) speakers at each store. The Madrigal Revel Salon Ultimas stood out as clearly superior to every other pair we heard over that period of a couple days that we spend listening to the best the competition had to offer. Every other pair had at least some minor unpleasant quality to their sound, these were the only ones where nothing stood out as an obvious imperfection to their ability to accurately and dynamically reproduce recorded music.

lenslens007's picture

If you did not like the sound of them, maybe there was some other part of the system that was producing noise that you did not like. I know they can reveal sonics in cables, DAC filters, room acoustics, and pre-amp. They also throw a large magnetic field that can interact with close-by (i.e. between the speakers) electronics.

makrisd's picture

When and where did you hear these? What is your favourite speaker system?

Ornello's picture

I own Yamaha NS-1000M speakers. Prior to that I owned Rogers Studio 1s. Either of these trounce the Revels.

steve59's picture

I got lucky enough to get a pair to and these speakers live up to their reputation bigtime. I'm generally disappointed by hi-end loudspeakers because my mid-fi electronics tend to translate into harsh, ultra revealing noise that's not musical, in fact I was in the process of upgrading my electronics when I found these and drivin by an anthem 225I and kimber 4tc wire these are the most impressive and musical speakers i've had and I can finally say my home system sounds as good as the systems I hear at the hifi stores. I'm sure better electronics will produce better sound but it's nice that they sound great as is. previous speakers, revel f52, VA beethoven, kef 107/2, 105/3, Dyn audience 80. The 107/2 are full range but can't compare to the salon.

amh020's picture

Dear Ornello,
I also own Yamaha's NS1000 and I am familier with the Salon2. I think the design strategies of both speakers are not that different. Recent measurements on NS1000 drivers show that the big mid driver has exceptional dispertion even at 5K. Distortion levels at around 1KHz are extremely low, like no cone driver can give. The Yamaha's sound extremely detailed without dynamic compression. The Salon2 sounds like that too, a bit less detailed in the mids and a bit more modern (laid back). And if you haven't upgraded some filter components then I believe the Salons can sound better then the yamaha's.
The Salons were and still are a high-end bargain, if your amp can handle the low impedance. If you can't afford them, buy second hand Yamaha's and recap the filters.

Ornello's picture

No way. The Revels are horrid in every way. Typical American speakers, 'badass' rather than good.

steve59's picture

You're passionate about your taste i'll give you that, but why hang around here and slam one speaker in favor of another when both are out of production? I read the review of the ns1000 and tbh I would take the dq10 they compared it to over a speaker that will make 5% of my recordings magical and the other 95% unlistenable, been there, done that.