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Since its inception ten years ago, the Harbeth User Group's ambition has been to create a lasting knowledge archive. Knowledge is based on facts and observations. Knowledge is timeless. Knowledge is human independent and replicatable. However, we live in new world where thanks to social media, 'facts' have become flexible and personal. HUG operates in that real world.

HUG has two approaches to contributor's Posts. If you have, like us, a scientific mind and are curious about how the ear works, how it can lead us to make the right - and wrong - decisions, and about the technical ins and outs of audio equipment, how it's designed and what choices the designer makes, then the factual area of HUG is for you. The objective methods of comparing audio equipment under controlled conditions has been thoroughly examined here on HUG and elsewhere and can be easily understood and tried with negligible technical knowledge.

Alternatively, if you just like chatting about audio and subjectivity rules for you, then the Subjective Soundings sub-forum is you. If upon examination we think that Posts are better suited to one sub-forum than than the other, they will be redirected during Moderation, which is applied throughout the site.

Questions and Posts about, for example, 'does amplifier A sounds better than amplifier B' or 'which speaker stands or cables are best' are suitable for the Subjective Soundings area.

The Moderators' decision is final in all matters regarding what appears here. That said, very few Posts are rejected. HUG Moderation individually spell and layout checks Posts for clarity but due to the workload, Posts in the Subjective Soundings area, from Oct. 2016 will not be. We regret that but we are unable to accept Posts that present what we consider to be free advertising for products that Harbeth does not make.

That's it! Enjoy!

{Updated Nov. 2016A}
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Working with the human ear: the proper evaluation of audio equipment incl. amplifiers

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  • #46
    Modern price/performance ....

    Originally posted by A.S. View Post
    With respect, you slightly miss - but emphasise - my point.
    Perhaps I do miss your point. However, there may be a reason.

    I think that it's fair to say that the sum total of what you have been saying here - which includes the proposal for an A/B amp switchover comparison - is that modern audio technology, in many areas, is either as good as it can be, or as good as it needs to be given the limitations of the human ear. Exotic cables don't matter. Amp differences are inaudible or insignificant when comparative loudness is properly controlled. Digital replay has reached the point at which it's as good as it ever needs to be, whether at 16/44.1 or higher. Many would still argue these points, but I won't - you've quite convinced me.

    So what's left to improve, then, in terms of real performance? To borrow your term, what does "real innovation" look like?

    Based on what I've read here, I would say that the areas in which real performance improvements could be made are: (1) speakers, (2) room/speaker interface, and (3) equalization. Am I mistaken? Would a revitalized hi-fi industry have anything to contribute other than with respect to (1)? And isn't the PC, with proper software, extremely well-suited to deal with (2) and (3)?

    Yes, things aren't what they used to be. But are they really worse? Isn't better sound than ever available to more people than ever, at a reasonable price too if they know how to go about achieving that?

    One last comment: I think it's more likely to be productive to go where people already are, and try to change that landscape for the better, than it is to try to drag them back to where they're not (stereo as a discrete, standalone hobby). The latter has been taken over by the audiophiles, as you point out, and they're not a large group in absolute terms. And yes, Sony may have lost out to newer competitors, but isn't that the way of the world? You can't put that down simply to a fragmented public - Sony has made some bad decisions along the way as well. I don't want to seem to be banging the drum too hard for Apple, but isn't the positive take on what they've done is to show that people will not hesitate to spend their money on your products if they perceive that your products (1) are better than those of the competition ("better" to a user, not necessarily to an engineer, so can include human interface, ease of use and aesthetics as well as sheer performance), (2) enhance their quality of life. Don't forget that, 10 or 15 years ago, many had given Apple up for dead. So perhaps anything is possible - but it requires real innovation, and multidimensional innovation not just technical innovation.

    Comment


    • #47
      Seriously...

      Originally posted by EricW View Post
      Don't forget that, 10 or 15 years ago, many had given Apple up for dead. So perhaps anything is possible - but it requires real innovation, and multidimensional innovation not just technical innovation.
      For real.... however think that there may still be some confusion between innovative marketing and innovative products. None of apple’s products I dare say were innovative. The technology was existing in actual working items, in some cases decades old. I'm not saying apple users are simple or shallow but you have to give the organisation credit for making their products accessible, mostly easy to use and desirable, factors which most more technically focussed entities tend to factor in last.

      Personally I wouldn’t buy a product from an organisation which doesn’t give me flexibility but puts me straight into the path of obsolescence eg. no slots for additional sd card memory, too troublesome to replace batteries etc. This surely must be innovative marketing (and war chest building) rather than thoughtful customer focussed engineering.

      Talking about a war chest, with what apple has in resources, it can do some real damage in terms of technology. Are they prepared or have the capability to do it?

      Comment


      • #48
        Heard but not seen!

        Originally posted by EricW View Post
        Based on what I've read here, I would say that the areas in which real performance improvements could be made are: (1) speakers, (2) room/speaker interface, and (3) equalization. Am I mistaken? Would a revitalized hi-fi industry have anything to contribute other than with respect to (1)? And isn't the PC, with proper software, extremely well-suited to deal with (2) and (3)?
        I agree that there is scope for work in all the above areas.

        Most of the innovation in audio in the last ten years has taken place in the realm of convenience and not sound quality. Offerings such as the iPod, and streaming solutions like Sonos, supported by internet based music services that allow for multi room multi user friendly home audio. It looks to me like the future of home audio is in the direction of streaming music services - and the better ones offer sound that is comparable to any good source. Forget about buying CDs, why even buy from iTunes if the music you want is available when you want it from a service provider?

        Further, let's admit the look of even Harbeth speakers appeals to only a minority. It doesn't usually add to the look of the modern home, and if you ask most wives, it takes away from it. They put up (speakers, hifi) to humor the men, most times, and hate the associated cabling that is an inevitable part of hifi set ups. Harbeth is seeing growth because it caters to a niche market, that is large enough for its scale and size.

        I see that there is also scope therefore in the area of providing quality audio through the home in a manner where it can be heard, but not seen. Streamed via music service providers, selectable and controllable from handheld devices, in a very user friendly manner.

        Comment


        • #49
          The Apple business model

          Originally posted by kittykat View Post
          For real.... however think that there may still be some confusion between innovative marketing and innovative products. None of apple’s products I dare say were innovative. The technology was existing in actual working items, in some cases decades old. I'm not saying apple users are simple or shallow but you have to give the organisation credit for making their products accessible, mostly easy to use and desirable, factors which most more technically focussed entities tend to factor in last.

          Personally I wouldn’t buy a product from an organisation which doesn’t give me flexibility but puts me straight into the path of obsolescence eg. no slots for additional sd card memory, too troublesome to replace batteries etc. This surely must be innovative marketing (and war chest building) rather than thoughtful customer focussed engineering.

          Talking about a war chest, with what apple has in resources, it can do some real damage in terms of technology. Are they prepared or have the capability to do it?
          I agree too. I am not a apple follower because whatever linked to apple need to use solely their way. Apple is user friendly? I do not think so instead it force user to follow whatever they give you. Lacking in memory slot, unchangeable battery, itunes etc are the thing I hate the most. To me it only lead people to blind follower. After a yr or so the only way is buy a new i-tem. Excellent marketing. They are many i-people think I am stupid because I am using android phone.
          "Bath with Music"

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          • #50
            Software switching?

            I wonder if there is a software application that exists or could be written that could do the job of the A-B switch box. That in itself could manage the switching from either a control room, or by the user. This could be useful to the average listener (or audiophile) as it could be downloaded from the net, and used by many. It could also include a "gateway" that would ensure that all devices are set at equal volumes.

            cheers

            george

            Comment


            • #51
              How to test ...

              Hi, all, esp. Alan Shaw,

              another use for the switch over box? of course it is possible to reverse the cabling an test 2 pairs of loudspeakers connected to one amplifier, but how would I address differences in sensitivity/loudness? could it be done with very simple tools?
              regards,
              Peter

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              • #52
                Amp challenge update please

                I am following this thread with great enthusiasm here at {an audiphile forum}

                A Number {of members} have indicated they are making proposals to you directly, this week. As I am unsure how many are posturing, is it possible for you to keep us in the loop as to how many have approached you to take up the challenge and what the results were?

                {Moderator's comments: Of course we will. We don't think Alan can be fairer or clear or more helpful. He has even provided links and costs for all the components necessary.}

                {See Alan's reply post #58}

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                • #53
                  So the Amp has little impact on Sound Quality? ... What about other components?

                  I am New Harbeth Owner, (Mar 20th, 2012 I was christened : ) ) and audio enthusist. I am building up the components in my system piece by piece over the years, most recently the SHL5s.

                  My problem is that few in the community are willing to speak as opening and honestly as Harbeth is about what is real versus imagined improvments in system quality. As you are all aware, the consensus is that you must view the system wholistically, spending an arm and a leg for each component. Any disagreements are met with abuse.

                  So my question is... What are the critical components and in what order? Details on why woould be very helpful.

                  Comment


                  • #54
                    Top culprit .... mechanical parts 'cos they MOVE!

                    Originally posted by lugbutz View Post
                    ... My problem is that few in the community are willing to speak as opening and honestly as Harbeth is about what is real versus imagined improvments in system quality. As you are all aware, the consensus is that you must view the system wholistically, spending an arm and a leg for each component. Any disagreements are met with abuse.

                    So my question is... What are the critical components and in what order? Details on why would be very helpful.
                    This has been touched on before. Top of the list is anything mechanical. Speakers, turntables, cartridges, microphones, tape decks ..... anything with moving parts. Moving parts means there is no perfect sonic or engineering solution and elements of the moving system will flap about (means RESONATE) at some note or other. Solution >>>> bond everything with superglue to stop the resonance but then the mechanical components can not longer move so they can't make sound!

                    Behind that is the room. The untreated room absolutely kills sound quality.

                    As for the rest ... you decide.

                    Comment


                    • #55
                      How to accurately compare two loudspeakers ...

                      Originally posted by chirhonix View Post
                      Hi, all, esp. Alan Shaw,

                      another use for the switch over box? of course it is possible to reverse the cabling an test 2 pairs of loudspeakers connected to one amplifier, but how would I address differences in sensitivity/loudness? could it be done with very simple tools?
                      A very good question. To answer as I see it:

                      1) Amplifiers (usually) have volume controls, and after connecting-up and switching on, the volume control will be advanced to some entirely arbitrary position. Ignore the markings on the front panel (if it has any*) because there is absolutely no correlation at all between the power output from amp A at 12 o/clock and amp B at 12 o/clock. So, this entire thread is about the impossibility of comparing amps when the user has not the slightest idea about how loud they are playing ... and therefore, because of how the ear works, they may attribute a sonic difference to the amps circuitry when in fact, it is just nothing more than a loudness difference. This you have already read. It could, as you suggest, also be a loudness difference between speakers, recordings, rooms, pick-up cartridges, microphones, CD players, cables .... absolutely any source. It's not just about amplifiers!

                      2) The next step you have to consider very carefully.

                      Speakers do not have volume controls. They are passive devices and just do their best to convert electricity-in, to sound-out. They don't have 'gain' like amplifiers, they only have 'loss' - that is, 99% of the electricity that arrives at their terminals does not generate sound, it generates heat. A speaker is about as (in)efficient as an old coal-burning steam train: grossly inefficient.

                      Now, in the real world there may be two speakers on demonstration at a store. A gives 95dB sound output for a watt of power in, and B, 99dB. Strictly speaking - exactly as you say - the 99dB speaker should be turned down by 4dB to replay at the same level as A. Since the speaker doesn't have a volume control, that implies that the amplifier would have to be turned down, and then turned back up again for the 95dB speaker for the same sound pressure at the listener's ears. Agree?

                      Problem: the dealer doesn't have a fast way of switching between the speakers as they did in the old days with a comparator (link is here, we've been around this before!) which allowed any amp, tuner, turntable to drive any speaker at the click of a switch (an amazing device, really). So that means, turning off the system, swapping the speakers, reconnecting, turning on and then, just as before, advancing the volume to an arbitrary position - oh, and then remembering to turn up or down a further 4dB .... How far is 4dB on the scale? There may not even be a scale. Is 4dB a 5 degree rotation? 10 degrees? 15 degrees? Without test equipment, your guess is as good as mine. So, in reality, it is not likely that two speakers of different sensitivity/frequency response can truly be compared unless all the equipment is calibrated and the settings totally repeatable.

                      What's the outcome: frankly, by maintaining a positive loudness differential between the speakers (by manipulating the volume control), the less sensitive speaker A can be made to sound louder (and better) than the more sensitive speaker B - just by how loud they are played! And loudest usually catches the consumer/audiophile's ear .....

                      We have to accept that that is how speakers are demonstrated and hope that the dealer makes a reasonable effort to equalise the loudness - but as the ear is not a precision loudness meter (far from it) the commercial realities of this situation will prevail: louder speaker will outsell quieter speakers.

                      Solution: for the lab, not really for the consumer for whom it's far too much trouble ..... use the switch-over box with some extra relay contacts. I've done this before. As the foot switch disconnects speaker A ready to connect speaker B to the amp, an additional signal is sent from the speaker change-over box to another change-over box mounted up at the amplifier input. That second switch box, under command from the first box, switches into the audio feed into the amp a small (adjustable) resistor to drop the 4dB (in this example) signal level so that speaker B, the naturally louder one, is selected and simultaneously receives an audio feed that is 4dB lower than A .... but as the speaker is 4dB more efficient, the loudness at the ear (which is what actually matters) should be the same.

                      Now this test, like the amplifier comparison, has a very interesting outcome and one I didn't expect until I tried it years ago. Loudspeaker B, which has a very strong personality in uncalibrated, uncontrolled tests, when driven at 4dB lower than A was almost indistinguishable from it. What really identified them was not the 'gross' performance, but the microtonal detail which was not immediately obvious once the gains had been carefully compensated for.

                      So, don't for a moment think that my observations about the effect of loudness is solely related to amplifiers - it's not.

                      * What a fool I am! I've only just realised that many/most? amplifiers do not have any volume markings on the panel! Some even have volume controls that rotate ten or more times! That's a charter for confusion ... judging levels is impossible.
                      Alan A. Shaw
                      Designer, owner
                      Harbeth Audio UK

                      Comment


                      • #56
                        Measuring SPL?

                        Thank you, Alan,
                        for the, as always overwhelming and exhaustive answer. Therefore would it be an approach to use a, maybe not so costly, spl-meter and a test tone to get some information about the overall loudness of speakers A and B and mark/remember the settings of the amplifier and change that according to the speakers playing? It would be of course too long for real comparison but would give some hints about the sonics more than just switching the chain?
                        Regards,
                        Peter

                        Comment


                        • #57
                          Originally posted by chirhonix View Post
                          Therefore would it be an approach to use a, maybe not so costly, spl-meter and a test tone to get some information about the overall loudness of speakers A and B and mark/remember the settings of the amplifier ...
                          Again, that's an entirely reasonable approach. The problem is in the practicalities. To my way of thinking, if there is a precision way of establishing level - and since the efficiency of the speakers is constant, as presumably is the room's contribution - measuring the electrical gain of the amplifier with high precision non-microphone based equipment seems the best approach. It also removes any uncertainties about the procedure of placing the spl meter in the room, rigidly affixing it, being sure that it doesn't electrically drift, susceptibility of the capsule to slight draughts which are undetectable to human skin but cause wild movement in the needle, measurement stability of the battery as it decays ..... lots of variable there.

                          In addition, you have the problem of what frequency to pick. One speaker may be atypically loud in a particular band where the other is atypically quiet*. Or do you use pink noise? Wide band or filtered? And by its nature, pink noise is pseudo-random and the needle of the spl meter will flicker ... and that flickering may be several dBs - far less precision than we need. It could and should be doable, but we'd need to test it thoroughly before we convinced ourselves that it would yield credible results, month in, month out. Remember: to remove loudness as a variable we have to aim to control or account for loudness variations to within a fraction of a dB. What is the scale of the meter? We need to be working in a zoomed-in displayed range of, say, 10dB.

                          *It is equally true that my method of gain-switching the amps wouldn't compensate for atypicality in the speaker response - or it could, if you measured the speakers and adjusted the amp gain resistors to offset the gain in particular frequency bands rather than at one spot frequency (say, 1kHz).
                          Alan A. Shaw
                          Designer, owner
                          Harbeth Audio UK

                          Comment


                          • #58
                            Please read before taking up the challenge! Updated clarifications ...

                            We proposed an A-B amplifier test on 29th March in post #6 in this thread to identify 'sonic differences' between amplifiers.

                            Re: post #52: Yes, I think I've gone further than I can be reasonably expected to do to help any would-be participants. I've even listed links to every component part needed to make the comparator unit with prices and part codes but I am open to providing any specific help other than actually designing or making the participant's switcher box. I would much prefer that you make the A-B switcher and not use mine to remove the shadow of doubt that somehow my design is compromised.

                            I'm a little surprised that aside from the headline post #6, nothing of what I've taken considerable trouble to present here seems to have been read/reported by those excited by taking up the issue and those determined to kill the idea at birth.

                            To avoid needless time wasting to and fro, pointing out what is in black and white here in these 50-odd posts, let me repeat yet again: for reasons that we do not understand, it would appear that under instantaneous A-B switching driving Harbeth speakers, that amplifiers of broadly comparable technical performance and matched for gain are not readily distinguishable. That is not to say that 'all amps sound the same' under random, uncontrolled listening. If that one sentence would be passed on it may help better frame this issue.

                            Any/all approaches we receive will be posted here with named sources. If we do receive any correspondence we'll ask that the candidate confirms that he has read this entire thread and thoroughly understands what we are saying and why. We will provide here on HUG an open response to any proposals we receive and hope to be able to mutually agree on a methodology to proceed with. The M40.1s are in stock available for collection. Until that time, we reiterate our position which is stated already in this thread:

                            '... the selection of an amplifier should, in our view, be based primarily on pragmatic issues of its durability and longevity, styling, features and facilities, brand reputation, technical specification (power, hiss etc.) and after-care service back-up until such times as the claimed night-and-day 'sonic differences' can be validated as real, not illusory under non-sighted, controlled listening tests. If 'sonic differences' can be positively identified under controlled conditions then, obviously, they should be added to the list somewhere'.
                            We are very flexible about the precise details of the test, but we must agree everything in advance. It's up to the participant to step forward with a proposal about music, amplifiers, design/assembly of your all-critical A-B switch (photos please), duration of dwell on A or B, scoring method, binding nature of the test on both parties (lawyer's agreement?), Press communications after test, time of day, air temperature, measurement equipment used to determine gain, comfort breaks and food/drink, source equipment, speaker cables and interconnects, speaker stands, speaker and listener position in the room, pre-made test CD with mixed music or std. commercial CDs, who controls music player, how volume to be rigidly set throughout test, presence of adjudicators and so on. Taken together these add up to a worked-through proposal rather than just a desire to casually attend. What cannot be negotiated over is the use of standard Harbeth speakers as the amplifier load, the use of an instantaneous A-B switchover arrangement between the amplifiers and a short gap between switching A-B-A-B etc..

                            The only email address for worked-through proposals is [email protected]

                            To date, 28 April, not one worked-through proposal has been received by Harbeth. One suggestion has been declined (see post 87) which deletes the all-important A-B switch. This M40.1 challenge has now closed on 27 April, 23:59 having been open for 31 days.
                            Last edited by A.S.; 28-04-2012, 09:02 AM. Reason: Updated
                            Alan A. Shaw
                            Designer, owner
                            Harbeth Audio UK

                            Comment


                            • #59
                              Gear fetishism ...

                              Originally posted by muypogi View Post
                              On the camera analogy, in the days of pure analog cameras, that may be true, but with today's digital bodies, digital processing engines, in-body image stabilization, the camera body matters quite a bit. Of course, at a certain skill level and usage parameters, one can rightly assume that you can stop at a certain camera body level and spend the rest on lenses.
                              I'm not interested in digital camera bodies hence why I said film photography. Digital photography is afflicted with the same type of gear fetishism as audio though.

                              Comment


                              • #60
                                The A-B test is in stereo (of course)

                                Originally posted by Zemlya View Post
                                I'm not interested in .... afflicted with the same type of gear fetishism as audio...
                                What a perfect expression! I wish I'd thought of that myself! It is so extremely unhealthy to become consumed by any persuit that you cannot differentiate truth from fiction from normality from decency from opinion from emotion. That shady half-lit area is where fanaticism breeds. It's also the same backstreet in which marketers prowl. Fanaticism in any form is an absolute curse to civilisation and culture as it has the power to sweep both away.

                                The best investment the chronic audiophile can make is an annual subscription to The National Trust. An afternoon out in the countryside, in beautiful surroundings and away from the audio gear makes you aware of just how much bird noise we mask out. It gives the ears time to reset and renormalise themselves, and probably even improves long term acuity. Above all, it brings you into touch with nature and other humans. You're likely to bump into me and my wife, mother in law (and grown up children) on a Saturday or Sunday at an NT place. If you do, please say hello!

                                BTW: I don't think that I made it absolutely clear that the A-B test is in stereo, with a pair of speakers. That greatly magnifies the ability of the listener to detect amplifier (or speaker) differences due to the addition of perceptional components such as 'sound stage', 'depth', 'height', 'width' and so on.
                                Alan A. Shaw
                                Designer, owner
                                Harbeth Audio UK

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