Announcement

Collapse

HUG - here for all audio enthusiasts

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}
See more
See less

SHL5s balance in my room

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

  • #31
    Why does this surprise you? The last word on stand/speaker/room coupling

    Originally posted by jack667 View Post
    After doing a few tests recommended by others on hifiwigwam, I've come to the following conclusions:

    - We conducted a test where both speakers were lifted completely off the stands whilst music was playing - there was little to no reduction is bass boom around these frequencies

    - Granite slabs were placed under the stands with little to no effect

    - Stands were replaced with thin wooden stools, about 25" high. Little to no difference occurred.

    - Sofa was pulled out 50cm from the back wall, little to no difference occurred.

    - Speaker placement changed, little to no difference.

    - Introduced a heavy rug on the floor, little to no difference.

    ...
    I'm surprised that you're surprised that having made the effort to try these standard 'old wive's tales' you have concluded none work. Of course they can't work. It's impossible. And the reason is this .... low frequency waves have a long wavelength. So much so that they touch every single surface in the entire room without exception. They sneer at pathetic little inconveniences to their dominant energy like feet, spikes, granite slabs or small air gaps. They bridge all of these effortlessly and with negligible reduction in energy. These sound waves don't have eyes to be impressed with 'decouplers' .... they couldn't care less whether they are there or not. Once the bullet has left the gun, passing through a tissue is a complete irrelevance to the motion and energy.

    Common sense - a little lateral thinking: Ever heard a youngster driving past in his customised car, blacked out windows, lowered suspension, beat music playing loud? You can hear the low frequency beat on the street, in the next street, even across town in your home with all the doors and windows closed because low frequency sounds imply lots of energy ... and energy is not impeded by windows, doors and even entire walls in the low frequency range. So, obviously, there is nothing you can buy in a hi-fi store that can tame low frequency energy mechanically. There is just too much of it. That leave you with four and only four solutions -
    1. Make technical measurements of the acoustic properties of the room, about its latent absorption and design some heavy dampers to top-up the inadequate absorption of your room in appropriate frequency bands
    2. Use electronic EQ to reduce the amount of energy being produced by the speakers in certain especially irritating frequency bands
    3. Do nothing to the room, turn down the overall volume and/or sit closer to your speakers to reduce sound pressure into the room and/or use a bass tilt control (like the excellent QUAD one)
    4. Plug the port(s) in your speakers to add acoustic resistance and reduce their efficiency

    You have no other choices. None.

    If you believe otherwise, then your really should patent such an invention, because you have discovered a process for negating the laws of physics, and that could make you a very wealthy man.
    Alan A. Shaw
    Designer, owner
    Harbeth Audio UK

    Comment


    • #32
      P.S. In my earlier post (#9) I concluded 100Hz, but that was for a complete cycle - you have a standing wave at half a cycle, which there is very little you can do about as Alan notes.
      Incidentally using a pre-amp with digital signal processing to tailor the bass output to a specific room is common practice in top audio-visual multi-channel systems.

      Comment


      • #33
        I use electronic EQ between pre- and power amplifier, it's the cheapest, simplest and most effective approach in getting rid of annoying peaks in the low range.
        Don't let yourself be influenced by the audiophile community. Use common sense, use objective testing methods, apply the laws of physics and don't get caught up in looking for the next best thing. Do this, and you'll enjoy music, that I promise you.

        Comment


        • #34
          Standing waves - a curse

          Originally posted by davidlovel View Post
          P.S. In my earlier post (#9) I concluded 100Hz, but that was for a complete cycle - you have a standing wave at half a cycle, which there is very little you can do about as Alan notes...
          The proof that one or more frequencies are related to standing waves is this (very simple, cost zero):

          Generate the frequency that you are having problems with either as a discrete frequency (say, 52.5Hz) or perhaps better, generate pink noise in a one-third octave band roughly centered on the problem frequency. Now, with that tone or band playing walk diagonally across the room, then from side to side, back to front. Listen carefully. If there really is a standing wave problem at that frequency you will find that at some rather well defined points in the room (perhaps +/- one foot step) there will be complete silence: the tone will vanish. Another step back or forward and it's there again. Another step on and the tone may be even louder.

          If you do find those frequencies (and I guarantee that you will in a normal, untreated room) they are related to the wavelength of sound being reproduced and the dimensions of the room. Since you cannot change the wavelength (unless you change the pitch), and you cannot change the room, you are left with options -
          1. Position your listening seat somewhere in the room that as-best-as-possible reduces the obviousness of the peaks and troughs so that they are least objectionable
          2. Add damping at those frequencies to partially absorb some of the energy bouncing back and forward (this is not easy: you need a lot of damping which will be big and unattractive)
          plus the suggestions in my post # 31.

          Do not waste time, money or effort on any other solutions. They cannot and will not work. The science of acoustics is one of the best understood, and there is nothing new to discover that has not already been well documented. There are very few patents in the area of building acoustics because there are no miracle cures. It's all basic high school physics.
          Alan A. Shaw
          Designer, owner
          Harbeth Audio UK

          Comment


          • #35
            My living room is not a studio

            Originally posted by A.S. View Post
            I'm surprised that you're surprised that having made the effort to try these standard 'old wive's tales' you have concluded none work. Of course they can't work. It's impossible. And the reason is this .... low frequency waves have a long wavelength. So much so that they touch every single surface in the entire room without exception. They sneer at pathetic little inconveniences to their dominant energy like feet, spikes, granite slabs or small air gaps. They bridge all of these effortlessly and with negligible reduction in energy. These sound waves don't have eyes to be impressed with 'decouplers' .... they couldn't care less whether they are there or not. Once the bullet has left the gun, passing through a tissue is a complete irrelevance to the motion and energy.

            Common sense - a little lateral thinking: Ever heard a youngster driving past in his customised car, blacked out windows, lowered suspension, beat music playing loud? You can hear the low frequency beat on the street, in the next street, even across town in your home with all the doors and windows closed because low frequency sounds imply lots of energy ... and energy is not impeded by windows, doors and even entire walls in the low frequency range. So, obviously, there is nothing you can buy in a hi-fi store that can tame low frequency energy mechanically. There is just too much of it. That leave you with four and only four solutions -
            1. Make technical measurements of the acoustic properties of the room, about its latent absorption and design some heavy dampers to top-up the inadequate absorption of your room in appropriate frequency bands
            2. Use electronic EQ to reduce the amount of energy being produced by the speakers in certain especially irritating frequency bands
            3. Do nothing to the room, turn down the overall volume and/or sit closer to your speakers to reduce sound pressure into the room and/or use a bass tilt control (like the excellent QUAD one)
            4. Plug the port(s) in your speakers to add acoustic resistance and reduce their efficiency

            You have no other choices. None.

            If you believe otherwise, then your really should patent such an invention, because you have discovered a process for negating the laws of physics, and that could make you a very wealthy man.
            You shouldn't be surprised Alan. Some of us are learning along the way. All I've done is try what people have been kind enough to suggest - now I understand that yes, of course, none of this will help. Without a full understanding of the science behind sound-waves from someone like yourself (like your 'average' person, right?), you can only go on what people suggest on forums - here being an example.

            Digital EQ is the way forward for me - it's cheap (models like Behringer or Alesis which we've used professionally in the studio) and more importantly it's discreet. I love my hifi, but my living room is a living room - not a studio. What I'd gain in Hifi with a better sound, I'd lose in an aesthetically displeasing room.

            After a little bit of research, the Behringer Digi-EQ looks like excellent value for money, and could be exactly what I'm looking for.

            Thanks all for your help.

            I'll report back when it's arrived.

            Comment


            • #36
              I am neither a scientist, nor research engineer, nor lecturer nor academic. I am that ordinary bloke you mention. None of this stuff is especially complex and should be within the grasp of the average 18 years old with an open mind. There really is no excuse for the almost total absence of science in audiophila.

              You just have to have a really good sense of when the presented facts do not fit with common sense. To be a good experimental scientist (like Michael Faraday) you have to constantly look for reinforcements of your theories in the real world, or conversely be prepared to scrap them and reconsider when day to day observational life just doesn't agree with them.
              Alan A. Shaw
              Designer, owner
              Harbeth Audio UK

              Comment


              • #37
                You partonise me

                Originally posted by A.S. View Post
                I am neither a research scientist, nor engineer, nor lecturer nor academic. None of this stuff is especially complex and should be within the grasp of the average 18 years old with an open mind.

                You just have to have a really good sense of when the presented facts do not fit with common sense. To be a good experimental scientist (like Michael Faraday) you have to constantly look for reinforcements of your theories in the real world, or conversely be prepared to scrap them and reconsider when day to day life just doesn't agree with them.
                Evidently not Alan, otherwise there wouldn't be a 5 page thread on the other forum (nor the 2 pages on here).

                It's logical sense to you because you have a thorough understanding of it, nothing to do with 'common sense' - I find your post quite patronising.

                I appreciate your help nonetheless.

                Comment


                • #38
                  The average 18 year old

                  Unfortunately "within the grasp of the average 18 years old" does not mean now what it did 50 years ago:

                  Basic physics: Wavelength X Frequency = Speed of sound (if you are considering audio waves)

                  Comment


                  • #39
                    I refute

                    Originally posted by jack667 View Post
                    ...It's logical sense to you because you have a thorough understanding of it, nothing to do with 'common sense' - I find your post quite patronising...
                    You must have misunderstood me.

                    I came into this industry (from semiconductors) knowing almost nothing. I know somewhat more now because I have put myself out over long hours over days, months and years to learn by personal experiment, to test, wherever possible and as carefully as possible, how great audio is achievable and to document the journey extremely carefully in Log Books. Nothing was logical or obvious at the beginning. But a good dollop of common sense at every turn makes a dedicated experimenter hesitate before accepting BS as fact. Facts have an integrity to them that is consistent from whatever direction you approach them - mechanical, electrical, acoustic. BS doesn't: it's one dimensional. I have freely shared that knowledge here over a vast number of posts to give the reader the fast-track to answers that I believe he could prove for himself by simple experiment (example here, CD player comparison). He does not have to - and shouldn't - necessarily take my word for it.

                    No more skills are required than an open mind, a resistance to the pack mentality and a willingness to commit to study. If I can weed out the facts from the BS by nothing more than common sense out of personal curiosity, it really can't be that difficult can it? If my personal, internal automatic response of "OK, now prove it" was everyone's automatic response, the industry wouldn't be where it is now, and billions of dollars of wasted expenditure chasing impossible solutions would have been saved by frustrated consumers
                    Alan A. Shaw
                    Designer, owner
                    Harbeth Audio UK

                    Comment


                    • #40
                      Originally posted by A.S. View Post
                      ... I came into this industry (from semiconductors) knowing almost nothing. I know somewhat more now because I have put myself out over long hours over days, months and years to learn by personal experiment, to test, wherever possible and as carefully as possible, how great audio is achievable and to document the journey extremely carefully in Log Books. Nothing was logical or obvious at the beginning. But a good dollop of common sense at every turn makes you hesitate before accepting BS as fact.

                      No more skills are required than an open mind, a resistance to the pack mentality and a willingness to commit to the task. If I can do it out of personal curiosity, why can't others?
                      I respect your opinion, as you must respect mine.

                      However, I'm not in the industry, I'm the consumer. I produce music (partially for a living), therefore I do have a good understanding of audio production, as well being fortune enough to work with a top mastering engineer at Air Studios London who has an excellent understanding of all things audio related. However, when it comes to acoustics (or 'common sense' physics as you'd put it) - maybe I'm just not up to scratch, therefore turned to a forum (or two in this case) for some help. Your background makes no difference to me Alan, I could say the same working in the advertising industry for the last 12 years - I came into it knowing nothing, with no qualifications, yet now I am the master of my trade. When someone asks me something as simple or obvious as how to rotate a photo, I'd never state that the person must use common sense to figure it out (which in this day and age - everyone must learn something so basic at school, right?)

                      Let's face it, the average person has no interest in audio at all, so when I'm asking questions about a niche product, in a very niche market, at least I've gone to the trouble to use (some of) my knowledge of what I actually understand (conducting a sine wave frequency test) - so what's really to quibble about here?

                      Let me make one thing clear: I'm not trying to start an argument, I'm merely intrigued and mystified (clearly) as I want to get the bottom of my problem. As I've stated before, I've been really impressed with your product.

                      As mentioned previously, I appreciate everyone's feedback.

                      Thanks

                      Comment


                      • #41
                        Originally posted by jack667 View Post
                        Evidently not Alan, otherwise there wouldn't be a 5 page thread on the other forum (nor the 2 pages on here).

                        It's logical sense to you because you have a thorough understanding of it, nothing to do with 'common sense' - I find your post quite patronising.

                        I appreciate your help nonetheless.
                        I think jack667 is undergoing the same learning process Alan describes in his posts, just perhaps a bit later in life. The difficulty with that (as I know from experience) is that there's more to unlearn as well.

                        Also, I think that one of the consequences of learning something well and thoroughly is that one internalizes to the point that it seems "natural", it becomes part of you, and it consequently can be difficult to understand why something that to you is as obvious as sunshine is something that may be more difficult for others to grasp.

                        To jack667 I'd say, Alan's manner of expression can sometimes seem a bit severe, but it's all a consequence of his intellectual passion (IMHO). The last thing he'd ever do is patronize anyone, much less a HUG user.

                        Comment


                        • #42
                          What do we mean by 'common sense'

                          Originally posted by jack667 View Post
                          ... I'd never state that the person must use common sense to figure it out (which in this day and age - everyone must learn something so basic at school, right?) ...
                          We are talking at cross purposes. I wouldn't have invested hundreds - thousands of hours here on the HUG if I believed that science was as simple as the application of a little common sense.

                          What I am saying is - and I repeat - the failure to apply comparisons (let's call it common sense) between the sort of issues that occur over and over again in home audio with life experiences outside the listening room in the real world creates a knowledge void filled with snake oil. One serious issue with the internet is that it creates the instant expert but it takes real effort and (that word again) 'common sense' to 'smell' an opinion that just doesn't seem to fit with ones real-life experience outside audio. Science is science and it must be consistent throughout the universe, so if you read that an aerosol spray dusted over your equipment will transform the sound of your system, does that square with your observational experience in the real world outside the listening environment? What other example can you draw on of the transformational power of an aerosol except perhaps in a health spa? If it does, then for you the magic aerosol is a must-have regardless of what others say. If it doesn't then your 'common sense' rejects the very notion of sonic aerosols.

                          It's not the arrival at the technical truth by the application of common sense we are stumbling over - that couldn't be expected of any non-specialist in a science field - it is the rejection of what are exceedingly unlikely to be technical truths by the application of (that word again) common sense. That's quite a substantial difference of emphasis.

                          Please remember one thing that may not be obvious. When I reply or comment here, I am not just attending to the specific issue for the specific respondent, I am trying to present a broader, simplistic, more universally applicable response (including this one) that will save me having to re-visit the issue again as I am not able to devote routine time here.

                          I hope that completely resolves any misunderstanding about common sense.

                          P.S. The acid test of my suggestion that it is the failure to apply common sense to compare and contrast with real-world experiences that leads us up the garden path would be to chose a subject we may mutually know little or nothing about. Plenty of choice for me: wine? Or nuclear physics? Or fish husbandry? Construction of the PostScript language perhaps %%? Let's stick to wine. We set off with an objective to find a really great wine, and we start mixing with wine experts. At first, we absorb knowledge like a sponge: it's all new and exciting, but we reach a point where contradictions and doubts start to creep in. One says that his flavour is certainly due to the unusual soils in his vineyard irrigated from a clean stream. Another says that, no, the secret of his great wine is that of the full moon shining on the bald heads of the peasant workers as they pick the grapes after midnight. A wonderful romantic story! You can see it in your mind's eye! But really, a little application of common sense surely tells you - even if you know absolutely nothing about irrigation or grapes - that the moonshine tale is nothing more than advertising puff. Or so it should. But that's not how audio works.
                          Alan A. Shaw
                          Designer, owner
                          Harbeth Audio UK

                          Comment


                          • #43
                            Acoustic is the final hurdle!

                            Originally posted by EricW View Post
                            I think jack667 is undergoing the same learning process Alan describes in his posts, just perhaps a bit later in life. The difficulty with that (as I know from experience) is that there's more to unlearn as well.

                            Also, I think that one of the consequences of learning something well and thoroughly is that one internalizes to the point that it seems "natural", it becomes part of you, and it consequently can be difficult to understand why something that to you is as obvious as sunshine is something that may be more difficult for others to grasp.

                            To jack667 I'd say, Alan's manner of expression can sometimes seem a bit severe, but it's all a consequence of his intellectual passion (IMHO). The last thing he'd ever do is patronize anyone, much less a HUG user.
                            I'm aware of this - it was just an opinion.

                            I really do love Harbeth products, and part of the reason I'm here is because I have actually wasted my own money on several different types of speaker without ever being truly happy.

                            Now I'm at the end of my search, the acoustics issue is my last and final hurdle.
                            Thanks guys!

                            Comment


                            • #44
                              Ha ha!

                              Originally posted by A.S. View Post
                              We are talking at cross purposes. I wouldn't have invested hundreds - thousands of hours here on the HUG if I believed that science was as simple as the application of a little common sense.

                              What I am saying is - and I repeat - the failure to apply comparisons (let's call it common sense) between the sort of issues that occur over and over again in home audio with life experiences outside the listening room in the real world creates a knowledge void filled with snake oil. One serious issue with the internet is that it creates the instant expert but it takes real effort and (that word again) 'common sense' to 'smell' an opinion that just doesn't seem to fit with ones real-life experience outside audio. Science is science and it must be consistent throughout the universe, so if you read that an aerosol spray dusted over your equipment will transform the sound of your system, does that square with your observational experience in the real world outside the listening environment? What other example can you draw on of the transformational power of an aerosol except perhaps in a health spa? If it does, then for you the magic aerosol is a must-have regardless of what others say. If it doesn't then your 'common sense' rejects the very notion of sonic aerosols.

                              It's not the arrival at the technical truth by the application of common sense we are stumbling over - that couldn't be expected of any non-specialist in a science field - it is the rejection of what are exceedingly unlikely to be technical truths by the application of (that word again) common sense. That's quite a substantial difference of emphasis.

                              Please remember one thing that may not be obvious. When I reply or comment here, I am not just attending to the specific issue for the specific respondent, I am trying to present a broader, simplistic, more universally applicable response (including this one) that will save me having to re-visit the issue again as I am not able to devote routine time here.

                              I hope that completely resolves any misunderstanding about common sense.

                              P.S. The acid test of my suggestion that it is the failure to apply common sense that leads us up the garden path would be to chose a subject we may mutually know nothing about. Plenty of choice for me - shall we say, wine? Or nuclear physics? Or fish husbandry?
                              Haha. Understood. I wholeheartedly agree with your point about 'Internet experts' - there's a fair share of b.s. out there.

                              Cheers Alan. Like I said before, if the digi-eq helps me then I'd be more than happy to share my findings.

                              Comment


                              • #45
                                Eq box

                                Would you like to borrow my Behringer? It is slightly modified in that I drilled an extra hole on the back and made a socket for a foot switch to turn the EQ on or off by remote (foot) operation.

                                The reason I did that was because I was working on a speaker design a few years ago, and the speaker had a small bump in its frequency response, as measured with the test equipment. It slightly offended me to see this little bump in an otherwise very flat frequency response curve. After a lot of dithering about unsure what to do for the best soldering passive crossover components on and off (which meant getting up from the hot seat, soldering both crossovers, sitting down again many seconds later) I decided to electronically eq-it out and see if it there was any audible difference, or even improvement (or worsening).

                                So, sitting in the hot seat with the EQ box wired-in between CD player and amp, I could operate the foot switch without moving and hear the instantaneous X/Y comparison of eq in v. eq out.
                                Alan A. Shaw
                                Designer, owner
                                Harbeth Audio UK

                                Comment

                                Working...
                                X