Announcement

Collapse

INTRODUCTION - PLEASE READ FIRST TO UNDERSTAND THIS FORUM!

"This Harbeth User Group (HUG) is the Manufacturer's own managed forum dedicated to natural sound from microphone to ear, achievable by recognising and controlling the numerous confounding variables that exist along the audio chain. The Harbeth designer's objective is to make loudspeakers that contribute little of themselves to the music passing through them.

Identifying system components for their sonic neutrality should logically proceed from the interpretation and analysis of their technical, objective performance, since deviations from a flat frequency response at any point along the signal chain from microphone to ear is likely to create an audible sonic personality in what you hear. That includes the contribution of the listening room itself. To accurately reproduce the recorded sound, as Harbeth speakers are designed to do, you would be advised to select system components (sources, electronics, cables and so on) that do not color the sound before it reaches the speakers.

For example, the design of and interaction between the hifi amplifier and its speaker load can and potentially will alter the sound balance of what you hear. This may or may not be what you wish to achieve, but on the face of it, any deviation from a flat response - and the frequency balance of tube amplifiers are usually influenced by their speaker load - is a step away from a truly neutral system. HUG has extensively discussed amplifiers and the methods for seeking the most objectively neutral amongst a plethora of available product choices.

HUG specialises in making complex technical matters simple to understand, aiding the identification of audio components likely to maintain a faithful relationship between the recorded sound and the sound you hear. With our heritage of natural sound and pragmatism, HUG cannot be expected to be a place to discuss the selection, approval or endorsement of non-Harbeth system elements selected, knowingly or not, to create a significantly personalised sound. For that you should do your own research and above all, make the effort to visit an Authorised Dealer and listen to your music at your loudness on your loudspeakers through the various offerings there. There is really no on-line substitute for time invested in a dealer's showroom because 'tuning' your system to taste is such a highly personal matter.

Please consider carefully how much you should rely upon and be influenced by the subjective opinions of strangers. Their hearing acuity and taste will be different to yours, as will be their motives and budget, their listening distance, loudness and room treatment, not necessarily leading to appropriate equipment selection and listening satisfaction for you.

If faithfully reproducing the sound intended by the composer, score, conductor and musicians in your home and over Harbeth speakers is your audio dream, then understanding something of the issues likely to fulfill that intention is what this forum has been helping to do since 2006. Welcome!"


Feb. 2018
See more
See less

The professional way to evaluate loudspeakers?

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Facts and experience about demonstrations

    Pluto has picked up on the very point I thought must surely have been misreported. 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, when, as I've mentioned before, the immediate and opposite oppinion have prevailed for me.

    Despite contributions which widen the subject and not visible yet, we've hardly scratched the surface of what those 50s show reports contain. If we want to build a solid foundation leading up to modern evaluation issues we absolutely have to squeeze every gramme out of these archive documents. We've found one statement (about small rooms) which we don't agree with. We can advance suggestions as to why from cross-alinking to some observations we've made in the non-DSP room correction thread. But the way I'd personally tackle this now is to note that of the 50s papers, one is clearly an advert (Carnegie Hall), one a write-up by a dealer (an interested party) and one by Briggs himself. All three have a spin. What I would do is run a pen through every statement that wasn't factually provable and see what facts we actually have available. The audience size and the on-stage equipment and personnel are presumably facts: but how much of what else fill the page is factual? Then I'd get a highlighter pen and highlight those facts which were pertinent to the loudspeakers.

    If I had Acrobat 9Pro here I could do it for you. Of course, I did this in my head long before I even started this thread - I should have pre-prepared the redacted copies.
    Alan A. Shaw
    Designer, owner
    Harbeth Audio UK

    Comment


    • #17
      Choice of music and who or what are we really evaluating?

      Some observations of the tests.

      1. Choice of Music seemed relatively narrow and selective, at least by current norms

      2. Choice of music correlates with the environment ie. a concert hall. Would the result be different if music like pop vocals, drums, small jazz ensemble or electronic music be used instead?

      There seems to be 2 parts of these tests which seemed not entirely clear and was confusing to me initially ie.

      1. are we testing the perception of the audience?
      2.or are we testing how good the sound system is?

      If the objective was to test how good a sound system is, wouldn’t there be a better and more scientific way eg. measurement rather then rely on humans? If it was to test hearing perception wouldn’t it be better to do it under (more) controlled circumstances?

      Comment


      • #18
        I agree. As you are discovering, the more you think about those shows, the less satisfactory the reported outcome.

        Had you thought about this .....

        - likely size of drive units
        - when the first tweeters appeared, and whether all/any of these speakers had separate tweeters or midrange drivers (exactly what drivers are in those strange boxes on top of the main cabinets)?
        - beaming

        to mention just a few.

        Alan /Tokyo
        Alan A. Shaw
        Designer, owner
        Harbeth Audio UK

        Comment


        • #19
          Qualitative or quantitative evaluation ....

          Originally posted by kittykat View Post
          ...are we testing the perception of the audience?...are we testing how good the sound system is?

          ...wouldn’t there be a better and more scientific way eg. measurement rather then rely on humans? If it was to test hearing perception wouldn’t it be better to do it under (more) controlled circumstances?
          Kittykat's subtitle "...who or what are we really evaluating?" is to consider. I'm surprised that since the begining of the thread, no one suggested a methodology to evaluate speakers, something pragmatic and reliable under many different circumstances, read environments.

          On my side, I clearly believe about human's evaluation. Just look Alan. He stated here many times: "I sit in front of the speakers I design and I'm the only judge." Even if there is always a parcel of subjectivity in human, they can have a truly scientific mind. I won't recall you here all the fabulous scientifics that we have in this world. I trust them.

          So my point is that to select "what we are really evaluating", do we look for qualitative facts or quantitative facts? Which method do we use? An analysis grid looks like a good starting point. We want something we can rely on everytime we need to.

          Maybe Alan can tell us what's his starting point when he evaluates a speakers, Harbeth or not. He's the specialist. I also want to hear you, HUGers. Where do you start your evaluation and how when you sit in front of a pair of speakers and want to appreciated them?

          Sebastien

          Comment


          • #20
            Getting to the core of the 50s public hifi shows

            Originally posted by Sebastien View Post
            Kittykat's subtitle "...who or what are we really evaluating?" is to consider. I'm surprised that since the beginning of the thread, no one suggested a methodology to evaluate speakers, something pragmatic and reliable under many different circumstances, read environments. ...
            Thanks for the feedback. However, although I sense a great desire to rush ahead and get to an analysis of how we should evaluate speakers/hifi eqpt. today, trust me: we cannot and must not do that until we have unpicked what we are slowly revealing as serious questions about those demonstrations from the 50s.

            If we were just studying why a few friends or journalists a lifetime ago had fun in the privacy of their own listening rooms evaluation this or that speaker, we here couldn't care less. Nothing for us to learn. But the fact is that whatever we finally conclude was 'going on' in the mind of the audience or in the skill or the presentation, upwards of 3000 people in jam-packed halls in the UK and USA (and probably elsewhere) were (reportedly) completely overwhelmed by the musicality of (mono) hifi equipment fifty years ago: they couldn't tell the difference between live or reproduced sound. Now that really is astonishing. To me that raises many serious questions which I (we) am (are) keen to attack, for my own satisfaction. Is it really possible that had I also been in the audience I would also have been carried along with the euphoria?

            I'm curious about those demonstrations which either fooled the public or misled them. Otherwise, the entire pursuit of stereo, digital audio and technical perfection in the reproduction chain since the 1950s is exposed as a completely unnecessary socio-economic activity. And we as ordinary hifi enthusiasts surely prove in our ordinary listening rooms every time we listen that the last half-century's technical progress certainly hasn't been. Or we are going to make the very same mistakes all over again when judging loudspeakers.

            Alan / Tokyo
            Alan A. Shaw
            Designer, owner
            Harbeth Audio UK

            Comment


            • #21
              A consideration of the audience ....

              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
              Attached Files
              Alan A. Shaw
              Designer, owner
              Harbeth Audio UK

              Comment


              • #22
                With a present memory of live sound

                Originally posted by A.S. View Post
                ... 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

                Comment


                • #23
                  Clarification please - what did 'live' actually mean?

                  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.

                  Comment


                  • #24
                    Those big spakers played loud ... at home?

                    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.

                    Comment


                    • #25
                      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
                      Alan A. Shaw
                      Designer, owner
                      Harbeth Audio UK

                      Comment


                      • #26
                        Frank Sinatra recording "The Concert Sinatra" (recording quality/style)

                        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!}

                        Comment


                        • #27
                          Stereophile shows?

                          Originally posted by Sebastien View Post
                          ...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

                          Comment


                          • #28
                            Studio recordings - and depth etc.

                            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.
                            Last edited by Macjager; 12-02-2011, 01:08 PM. Reason: Spelling and grammar

                            Comment


                            • #29
                              Depth

                              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.

                              Comment


                              • #30
                                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
                                Harbeth M40.1-Naim NAC52-Supercap-NAP 135-CDS2-XPS

                                Comment

                                Working...
                                X