The professional way to evaluate loudspeakers?

[A.S.]

Because we have photographs of the halls used for the demonstrations, we are provided with many clues that may help us understand these remarkable shows. All may not be as it seems.

What struck me initially when I found these reprints was how although the audience were reported as having been (universally) overwhelmed at what they heard - and that may have been true - what is certain is that they were not all hearing the same thing. Setting aside the particulars of their own individual hearing acuity (look at the age of the audience), we do know that loudspeakers are predictably directional. That's to say that we know that there is an optimum 'sweet spot' in the listening room, and that usually corresponds with the listeners ears on or about the 'reference axis' - where the designer would have clamped his measuring microphone and set about optimising the overall integration between bass, mid and high frequencies i.e. woofer and tweeter.

We also know from our own experience that if we listen even a few degrees off-axis, that is, to the side of, up or below that axis, the sound will be different. If we sit far off axis, or taken to an extreme, actually behind the speakers, the top diminishes greatly. So, our judgment of a speaker's sonic performance is critically linked to where we sit relative to it. Plus, of course, the actual design of the speaker, how far apart the various drive units are, how wide and tall the baffle is etc. etc.. We've looked at this off-axis issue before here, and my TechTalk covers exactly this point.

- We should also consider the size of the drive units common in hifi speakers of the 50s. These would have been typically 15" diameter or more, and would have been far more directional or beamy than modern 8" units, and with far less high frequency output especially off axis where the response would have dropped like a stone at even quite low frequencies.

- Had the tweeter been invented and fitted to any of these speakers? If it had, how big a cone (long before domes) would it have had? And we know that the bigger the cone, the more directional so even if a tweeter had been fitted, if it was of a 3 or 4" diameter paper cone, it would have had very weak off-axis output.

We've identified that perhaps only 20% of the audience were in or near the reference axis sweet spot. 80% will have been a little or a lot off axis. And yet, a reportedly euphoric success. How could the audience have been so enthusiastic when, from what we deduce, the majority would have been listening off axis?

We can look at the other pictures later.

Alan / Tokyo

[Sebastien]

... It is my experience that played in a large enough room and/or sufficiently far from the listener just about any speaker claiming to be of high fidelity will sound adequate or even good. That's rather interesting don't you think? It implies that the most advantageous place (for the seller) to demonstrate his speakers is in hall, on a stage, with the audience a considerable distance awaybut the least relevant or useful for the prospective buyer. I'm a little surprised that this point was not siezed on by other contributors as it is both my (and Pluto's) experience but maybe others have not been able to make a comparison of a speaker that sounds good at a hifi show with the same speaker at home...

There are different places where I can compare speakers or any other components:

1) High-Fidelity show, SSI in Montreal, where most of the speaker's demo are in poor small rooms without any treatments. Some companies, maybe with more money, can afford a larger room but were are not talking about a hall here. Usually, nothing impressive in there because of the inadequate listening conditions;

2) Hi-Fidelity store's demo rooms: some of them are very very impressive. The kind of place where I listen to speakers who impress me the most. The first time I heard a pair of Harbeth was in that kind of room. No WAF in there, no budget limit, all with a great evaluation and treatment of the room;

3) At home or friend's home in a normal listening room. Usually, the result sits in between example 1 and 2 depending of the treatment of the room.

To pursue with the quote above, I realize that I might have experimented for years many situations of "off-axis" listening at live show. Are we accustomed to this and refer to that audio memory while evaluating a speaker?

Again I make my pledge for musicians, they are closer to their instrument and the real "natural" sound they create. That's why there is always for me a huge difference between the drum I play at home and in jam sessions versus the one I hear in my system. I keep in mind that there is also the recording and the mixing processes important here. So many instruments sound live via my system, voices too.

I find those 1950s demonstrations exceptional. Why don't any modern hi-fi show don't do this anymore? Plus, to Alan's opinion it facilitates speaker's sells.

Anyway, on a curious basis, I would really like such a demonstration. In those conditions, you can't say: "My memory recall that this instrument sounds like this or like that..." No, you have it and hear it in front of you, live. You can switch from the recording to the live music in half a second. In my opinion, that is a good objective starting point to assess if a speaker sounds like a real instrument or not with a present memory of live sound.

Sebastien

[weaver]

May I just ask a quick question, the answer to which may be obvious to everyone else but is puzzling me?

In these demonstrations was the live sound also being played back through the speaker system?

I have read the articles a number of times and in places they refer to switching between live and recorded in a manner which suggests to me that both were going through the amplifiers and speakers, ie what was being compared was the speakers reproduction of a recording and the same speakers reproduction of an instrument being played live.

[kittykat]

Looking at the photo and how big the room is, I would imagine those speakers would be capable of going insanely loud in a smaller domestic sized room. I’d be interested in knowing how they would perform in a modern sized living room, at socially acceptable sound levels.

[A.S.]

As there are no mention of microphones in the equipment list, I think we can conclude that where the live performers were introduced, the recorded music would cease, except in the recorded + live organ piece. I guess that there was a system of cue lights. I'm not clear about whether there was an attempt to (virtually) seamlessly stop the replay over the speakers on a particular bar and allow the live performers to start or whether whole pieces were played through, then switched to live.

Did you notice the comment about how the pre-recordings were optimised to the hall and how those same recordings may or may not be suitable for getting the best out of the domestic hifi setup? Back to the thread on damping the listening room for consideration of that.

Ok, so what's next. Well I think we need to at least note that there is a fundamental difference between the loudspeaker on-stage in the hall and in the listening room. What's missing in the hall is the close proximity and sonic contribution of the side walls and the ceiling - the floor is the same in both although if you are seated near the stage, the floor bounce may well be above your head and not audible. But at home, there is no escaping the floor bounce unless, as I showed in the TechTalk, the listener is actually lying on the floor.

We know from the audio examples in the non-DSP room damping thread that early reflections (sidewall, floor, ceiling) have a critical influence on the perceived sound at the sweet spot. On stage, the side walls are far from the speakers and reflections off them whilst measurable may well present a completely different impression to the listener in the hall, if any at all. Certainly, the combination of very large drive units with directional high frequencies will spray far less HF laterally and that combination of narrow HF beaming plus side walls far from the speakers is a completely different situation to the real world domestic listening set-up.

Alan / Tokyo: Stereo Sound Award 2010 ceremony day

[Macjager]

In reviewing the articles in this thread, especially the "Live Shows" I began to wonder at how live recordings, ie no overdubbing, multi-track recording, sounded as compared to "in the studio work" (orchestra lays down music, singer comes in later with headphones and sings)?

I recently came across a 1961 Frank Sinatra recording with Nelson Riddle arranging and conducting. The description on the cover relates the equipment, personnel and location of the recording: to whit, Westrex 35 MM recorder, 24 RCA 44BX microphones, 8 track, 21 position mixer console, 73 musicians, and 4 sound stages of the MGM studios in Hollywood. The picture on the album cover front and back is of Sinatra, the orchestra, Nelson Riddle and all these microphones on really long arms hanging over the orchestra, yet no "live audience".

In listening to the album there is not a sense of recording in an airport hangar, rather a depth of sound as described by Alan. This concept of full sound and recording studio (or hall) is intriguing and i would like to explore other "live/living" recordings for comparison. Are there others who hear this and on what albums if so?

Cheers

George

{Moderator's comment: one thing to be wary of: do not assume that the publicity photo of the orchestra + mics + hall is the actual set-up used to make the recording. Any album photo is for 'marketing purposes' and not necessarily a legal fact!}

[Sebastien]

...I find those 1950s demonstrations exceptional. Why don't any modern hi-fi show don't do this anymore?...

A friend of mine told me this week that Stereophile actually do this with some audiophile clubs.

Sebastien

[Macjager]

Excellent point, from the Mod! I have further explored this idea in regards to this album and have been able to ascertain that the recording was done over three days, and that evidence points to the photo as probably accurate. Notwithstanding photo proof or not, I did hear two song today back to back, one was a live recording of Green Onions by Booker T and the MGs Concert for the Rock and Roll Hall of Fame, immediately followed by a studio recording of the Black Keys "Brothers". the Booker T song had depth* while the studio album sounded very much lacking. The studio album was very lifeless in comparison, like Alan's examples of recording in a non-reflective space (anoechic chamber) or what the musicians hear in the orchestra pit.

It is truly amazing what one can hear when focusing on music as the primary source of aural stimulus.

Cheers
George

*Depth - my definition of depth means that the sound continues slightly after you first hear it, not an echo, but a pleasant layer that remains for a short period of time as the next note arrives. It does not muddy the sound but seems to enhance it. A song that does not have depth is one where the sound stops almost as soon as it is heard, how you hear things in a space that deadens the sound instantly, ie no echo.

Sorry about the verbage, but when I read a lot of descriptions of music or a particular reproduction medium, (speaker, cable, pre-amp etc), I don't really understand what the author is trying to convey, for example, what exactly does "the speakers had a dark chocolate sound" mean...? Alan's sound clips that describe soundstage are excellent, but it takes a few listenings to understand the differences. This is what I am trying to convey in many words.

[hifi_dave]

I believe 'depth' refers to the depth of the sound stage, where you have layers of sound. With a small group, you would expect the vocals or soloist to be to the fore and the drum kit way behind. With classical orchestra there should be layers to the orchestra spread out between the speakers.

[delgesu]

yes, but especially with classical recordings you have a big issue concerning phase incoherency when (extreme) multi-miking was applied. if the mastering does not manage this then the "depth" is lost or artificial. it is not accidentally that some of the very old recordings (for example decca with their "decca tree" technique) give us a very fine flavour of what "depth" on a recording can be.

despite that it is interesting that in live performances of classical music i never had the feeling of things like "depth" as well as "focussed strings" or something like that. especially when attending the "bayreuth wagner festival" the only thing you recognize concerning ""depth etc." is a wall of sound. no focus, no depth, no nothing of the often quoted hifi-terms.

best,
delgesu

[kittykat]

You’re absolutely right delgesu.

Music has none of this fictional hifi concepts of “depth” etc. Isn’t depth etc. conjured up by the skill of sound engineers and technicians? Stereo is a phantom image after all isn’t it? I’ve read many letters to editors of hifi magazines by poor consumers who complain that they cannot perceive depth in their hifi systems etc. The truth is, there is very little of “this” in most recordings, except the nerdy ones tailored for the hifi equipment fetish-ed and fraternity.

Personally I think these concepts of “image”, “depth” are spun and perpetuated by some retailers (who play recordings with plenty of it during demonstrations) and manufacturers to keep people on the hifi merry go round. Sure there are speakers which can do it better than others, but it’s just the ability to reproduce a “trick”.

[delgesu]

kittykat,

100% my opinion!

additionally let me tell you that i lately was informed in a german music/hifi magazin by former engineer mr. heinz wildhagen (nearly 60 years engineer/producer for the famous german "deutsche grammophon" label) that ZERO records sound like the real performance at the recording venue (and he mastered/recorded/produced thousands of records). any master tape is mixed, some conductors want to highlight specific instruments or modifications whatsoever.

my conclusion after a lot of years with hifi and even more with music is that it is an illusion trying to recreate the "real location" in my head while listening to hifi. BUT: it is possible to identifiy the "smell" of the real thing concerning colours, timbre and real voices/instrumental sound. that´s it. and in the best case you enjoy this with a nice pair of Harbeths.

best,
delgesu

[EricW]

I agree with both delgesu and kittykat based on my own experiences at symphonic and other live concerts.

A distinction is often made between the live sound of "real" instruments and recordings which feature electric and electronic instruments. Maybe if we accept that all recordings are "artificial", the apparent dichotomy between the two becomes less important.

A question, however: why is it that a Harbeth sounds "better" even when reproducing a non-acoustic instrument? Because I think it does, but it seems more difficult to explain why.

[Gan CK]

kittykat,

BUT: it is possible to identifiy the "smell" of the real thing concerning colours, timbre and real voices/instrumental sound. that´s it[/U]. and in the best case you enjoy this with a nice pair of Harbeths.

best,
delgesu

Yes couldn't agree more on that with you Delgesu. Harbeths reproduce the natural colour, tone & timbre of real acoustic instruments & voices extremely well & is the reason why i am still so enamoured with Harbeth after so many years.

Like my buddy always say; you can almost smell the wood of the violin or cello on Harbeth. No other spks can do the above mentioned quite like a Harbeth. Not even electrostatics or Ribbons. But not many people know how to discern the natural colour, tone & timbre of real instruments & these people often say Harbeths are coloured when in actual fact they are simply too used to coloured spks that distort the tonal truth of real instruments.

[keithwwk]

Soundstaging and depth are both very subjective perceptions. In my observation and experience mixed with many type of audiophiles, different person detect both differently. If a hifi setup being detected with excellent big wide soundstage and depth by person A but person B may detect small narrow soundstaging and no depth from it. This all depend on how a person perceive his feeling from reflect or indirect sound. It is also happen on soundstage height. Same detect soundstage above speaker and some detected soundstage below the speaker in a same hifi setup.

Anyway, above mentioned is no longer bother me. When listen my Harbeth setup, all thing come out so natural, beautifull, always feel I am in a live musical event and totally into the music and nothing else can better than this "live" feeling...bath in music and purified into music....

mr. heinz wildhagen.....i remember his name in my DG album collections. He made plenty of good recordings..

[kittykat]

A question, however: why is it that a Harbeth sounds "better" even when reproducing a non-acoustic instrument?

In my opinion, electric instruments and modern recordings can be harder to "reproduce" (think its more accurate to say “to listen to”) due to the inherent noise, distortion and loudness. Add further inefficient conversion of electrical energy from amplifier to some speakers equals hurt and pain to the ears. Example...i tried listening to Bryan Ferry’s Olympia (not the best recording) on a pair of mini-monitor speakers (which will remain anonymous) and I just couldn’t continue after 4 tracks. Subconsciously my ear and brain was trying to fend of the attack from the mini monitors, which took all my attention (and enjoyment) away from the music.

I've put it back through the SHL5's now and I can enjoy the coolness of Mr. Ferry.

{Moderator's comment: what your are saying in technical language is 'Harbeth speaker have lower coloration than conventional speakers'. As we all know.}