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Hi-Fi racks - still a thing

Discussion in 'audio' started by evand, May 31, 2022.

  1. NickofWimbledon

    NickofWimbledon Well-Known Member

    Hi @TheFlash - yes.

    The clever glass in a Naim Fraim works remarkably well (which it should for the money), as long as you get it all just right. However, glass 'ringing' is a real problem in a lot of racks, especially if it is thin or the speakers are close enough to excite it.

    I have been biased against glass under a TT in particular for decades, but now have a piece of laminated glass under my LP12 after listening tests. However, that includes 4 rubbery feet from HRS and a cheap lump of granite too.

    That day's experiments included putting either of two bits of glass in place of the MDF board on my Targett turntable wall shelf. It was awful - shrill, echo-y, thin and lacking bass, focus and cohesion.

    We also tried putting the balls and cups from a Naim Fraim on the Targett's MDF board and then putting the glass on that, with the LP12 on top of the whole thing. It didn't look too bad, and it sounded better than than the above glass-only option, but it really wasn't right. Stereo image would be great at one moment and gone the next, sibilance was still worse than the MDF board on the Targett stand, and there was little weight behind drums on 'ok, but not wonderful' recordings - if you want to make John Henry Bonham sound like Charlie Watts, this may be the set-up that suits.

    Note that the results might have been different with a non-suspended turntable.

    My conclusion on glass was that just the right kind of glass can work well if supported in just the right way (so that resonant frequencies get squashed). If that isn't an option, the cliche about 'light and rigid' is still a good starting point for a turntable, and thick bits of wood or stone (not marble) or clever isolation platforms can improve a decent rack or make a sideboard into a perfectly good support even for the picky.
    Miss Ariel, Steven Toy and TheFlash like this.
  2. TheFlash

    TheFlash Superhero of Sound

    Thanks for the comprehensive reply. Some great experimentation there.

    You say “glass ringing is a problem in a lot of racks”: is this from repeated personal experience of a lot of racks? Not challenging, just seeking to pick my way through what is experience and what is hifi folklore.

    You also mention the “right kind of glass”. My Custom Design rack has 10mm toughened and I’ve never had any problem with ringing - well, not that I know of, I might have to play with alternatives.

    To me, glass onto wood (like my rack) or onto sorbothane or similar feet has never given issues, which makes me question whether it’s the glass itself which may cause issues or what that glass is connected to/resting on.
    Glass onto metal legs would of course risk making the whole rack sing, not just the glass shelf.
    Steven Toy likes this.
  3. NickofWimbledon

    NickofWimbledon Well-Known Member

    Lots of experience, but most of it not mine.

    I do know people who have complained about vagueness and worse from their speakers - some then mentioned that there also seems to be a buzz/ rattle (or some such) from their CD player/ amp/ one-box. In the first case (years ago), the latter turned out to be from the glass it sat on audibly vibrating (only 3 support points out of 4 making great contact), which is a hint about how good it was as a support. Fixing the rattling bit by sticking hefty books on it solved the second problem, but shifting the hifi box was also tried - and that is how it stayed.

    Over the last 35 years, I have probably had those conversations with 5 people, and in a couple of cases that meant me on the telephone suggesting 'Now try XYZ: how does it sound now?', so this really isn't a proper sample.

    These things affect non-hi-fi sideboards or budget racks much worse than a really good hifi rack of course. Irrespective of theoretical disadvantages about resonance, I am of course not suggesting that glass cannot be made to work well - see the comments from happy Naim Fram owners. On the other hand, I remember a lot of racks from 20-30 years ago (and many still use them) where the shelves were dreadful - particularly if you turned the volume up. Hence, my general view on glass can be classed as a prejudice that may well not apply to real cases now.

    My experiments with my LP12 are a good deal more robust than my generalisations, but we tried 6mm window glass and laminated glass. The special toughened glass on a Fraim clearly has no such issues, and they won't be unique. I have not heard your Custom Designs rack at all, but if it doesn't sound like it has a problem it probably doesn't.

    A you say, glass on wood or sorbothane cuts out one sort of issue, as long as it doesn't stop you keeping things horizontal - your amplifier may not mind but turntables and CD players do. As you also say, metal and glass together are particularly easy to get wrong.

    If you want to check for effects like these, you could get a trial pack of HRS Nimbus Assembles (i.e. feet) from The Audio Consultants for free, or just try putting cheap rubbery feet under boxes. If it sounds exactly the same (or worse), that may be a hint to stop fiddling. Sticking a wooden chopping block between hi-hi-fi and shelf is another easy experiment that many do.

    Of course, you can go further if you want and it can help. My Naim boxes sat on granite shelves and sounded great, but I still found some improvement putting those HRS feet under them. Some on the Naim site have done the same on their glass-shelved racks (with HRS or rival products), and some have added isolation platforms under boxes despite using good racks.

    It is also worth noting that some hi-fi boxes are affected more than others. Boxes with no moving parts (apart from electrons) are not as immune as you might think, but most boxes are not affected in how well they work to anything like the degree to which a turntable is affected.

    I am not too bad at the theory on all this, but concluded very quickly that applying the physics here is massively beyond me. Apart from anything else, so much of the sound we hear is driven by the listening room and its contents, and analysing things properly is a pretty huge task. Fortunately, we can use our ears - if it sounds less good than you expect or actively odd, your rack will be something to investigate, like bad connections, wobbly speakers or having 2 boxes close together that really don't like it (top example of that being having a flash phono-stage sitting for lack-of-space reasons on top of its hefty power supply box).

    Frankly, if it all sounds good, I wouldn't encourage people to go looking for issues - after all, you want to listen to music, not your hi-fi.

    On the other hand, an afternoon's experimentation, with some bother but little or no outlay, may result in slightly better sound even if you didn't think there was anything to 'fix'. If it results in no change at all, at least you will have the peace of mind of knowing that you are not somehow missing out (we can all worry about those incremental 1% changes) and can stop thinking about the subject altogether.
  4. James

    James Lord of the Erg\o/s

    Not glassy per se, but somehow not quite right. That was with a Naim CDS2 on Mana. I suspect its metal feet had something to do with it. Whilst it never convinced me it was worth the price difference from a CD2, it sounded best sitting on a carpeted floor. That being said, every other component I had then (mostly Naim) sounded indifferent and rather fine on Mana. My LP12 sounded best on Mana.

    Glass shelves that are evenly supported (and so don't rattle and ring evenly all round) don't really ring when a piece of hifi kit is placed upon it. This is easily established by tapping the empty glass shelf and then doing the same (from under) when loaded.

    This is also why I recommend removing glass from unused shelves.

    How can you have experience that is not yours? I think that is called anecdotes, rather than experience.
    NickofWimbledon and TheFlash like this.
  5. NickofWimbledon

    NickofWimbledon Well-Known Member

    On anecdotes (and data is not the plural of anecdote), we agree. I put a lot less confidence behind someone telling me that a change made a difference (even if it a change I suggested) than if I tried it myself.

    I also don’t have great hearing, but know everyone is different in what they hear and what they notice. And I am well aware of how easy it is to be persuaded that there is a difference and that the new arrangement must this be better. And unless something is badly wrong, I don’t expect changes to be night and day or revelatory - despite the claims, this should not be a difference like swapping stand-mount speakers for 4 foot high floorstanders.

    After all those caveats, this sort of tweaking can let you hear more music and enjoy it more, particularly if there is a weak spot somewhere.

    in a way, support is like speaker cable. Despite all the stupid claims and ridiculous products, they are not all the same, and a bit of effort can be repaid handsomely.
  6. NickofWimbledon

    NickofWimbledon Well-Known Member

    And on removing unused or unweighted glass shelves, that sounds very sensible to me.

    I am afraid I am not equipped for a proper discussion of resonance and transmission paths in glass. I am not sure that changing the resonant frequency by adding a weighty amp deals with the complex effects, though I agree it dramatically reduces or removes obvious ringing, but I’ll have to surrender that ground to someone who was at university later thann1985…
  7. Steven Toy

    Steven Toy Accuphase newbie

    This is a straw man.

    Glass has certain resonant properties but I would never report a 'glassy' sound.

    Glass can be made to work in some applications (Naim Fraim, Mana). In others it will ring along with any metal tubing between each shelf. This ringing will raise the audio noise floor in the listening room if such a resonant rack is present even if no equipment is placed upon it.
  8. TheFlash

    TheFlash Superhero of Sound

    I think we agree then but let me test this: glass as a material is not intrinsically problematic, but problems may arise from its application eg attached direct to (some) metal frames. Ok?

    I put the (some) in because I imagine that the solid stainless steel legs of some racks would, even if coupled direct to the glass, give fewer issues than the hollow legs of others.
    NickofWimbledon likes this.
  9. Purité Audio

    Purité Audio Trade: Purite Audio

    To return to reality for a moment, there would have to be enough structurally transmitted energy to create an audible resonance, you can check this with an accelerometer or even a glass of water placed on the shelf.
  10. Steven Toy

    Steven Toy Accuphase newbie

    Agreed wholeheartedly.

    There are so many variables, each with perfectly reasonable physical explanations in their own right, that the only reliable method is trial and error.

    Subjectivity finds the correct answer. The science will then always provide an explanation after the fact if you look hard enough The reverse is simply not practical even if desirable in some minds.

    Most engineers and true scientists (as opposed to those who use measurement and scientific theory to lend support to their dogma or ideology) accept that design outcomes can rarely be predicted in advance, given the number of conflicting variables.

    In the automotive industry CAD modelling will simulate the behaviour of a vehicle in a collision. The actual crash test then tells a different story...

    Someone once asked me to prove that this was the case; they asked for documented evidence, such was their absolute belief in predictability from measurements.

    The very fact that crash testing, which is a rather costly exercise, is required as part of the design, research and development process at all is all the proof you need! The documentation of crash test failures is generally kept secret for obvious reasons.
    TheFlash and NickofWimbledon like this.
  11. NickofWimbledon

    NickofWimbledon Well-Known Member

    @TheFlash - that looks right to me, but believe your ears ahead of my waffle.

    @Purité Audio - interesting point. I worried about airborne transmission as my B&W 804s do fire vaguely toward rack and wall-shelf. I worried about the speakers shaking my bouncy floor, and that the spikes on my rack would not stop all frequencies getting through. I worried that the gap between LP12 and CDS2 was smaller in my house than at a dealer or two- and they had concrete floors and Naim Fraims.

    I also worried that it doesn't take much vibration to affect a turntable - isn't that rather the point of needle-on-vinyl? And how sensitive would the accelerometer need to be to show vibrations comparable in scale & speed to those my MC is trying to measure?

    I don't know the means of transmission and I certainly don't know the transmission paths and the various resonances of all the items concerned. However, I am not sure my list of concerns all fall into 'structurally transmitted' category you mention.

    As fr the glass of water, I just tried that. If placed on the floor, it is good at detecting when buses are driving past, It also demonstrates clearly that putting my LP12 on window glass and Naim cups-and-balls works fine, despite our poor ears failing to recognise this and somehow finding that mixture unlistenable. Perhaps I need a more sensitive glass of water, though it i more likely that I am just doing the test wrong...

    Am I missing something obvious?

    In my case, let month 3 people listened to various tweaks over some hours and wrote what we thought. We compared notes. Sometimes the guitarist and/ or the clarinetist could see what I had changed (so not consistently a blind test) but they didn't spend much time watching me.

    The only major point of disagreement was that those with better ears than mine (i.e. both of them) could consistently detect whether the HRS damping plates (surely the most obvious woo of all?) were on pre-amp and phono stage, which I absolutely couldn't unless the volumes was more Motorhead than Brahms.

    It is possible that they secretly copied notes when I was not looking. It is also possible that we are psychic and 'knew' what each other thought/ wrote. To me, it seems more likely that the tweaking really did make a difference.
  12. Purité Audio

    Purité Audio Trade: Purite Audio

    Spikes directly couple, so all frequencies will ‘get through’, see if those two pairs of ears can reliably tell when comparing unsighted.
    Apart from turntables which are after all a seismograph and may benefit from some form of structural isolation ( bear in mind there is still airborne pressure changes to contend with ) everything else is just snake oil .
  13. NickofWimbledon

    NickofWimbledon Well-Known Member

    @Steven Toy - I think you are dead right.

    I should probably admit that my original degree (nearly 40 years ago) was Aeronautics. For most of flying history, designers had to ignore theory and rely only on what actually stayed in the air, though I am delighted to report that that is no longer true.

    Had they stuck in 1900-1970 to doing their best with theory (including fudging some equations that could not be solved analytically), instead of using what worked as a guide, the results would have been unfortunate.

    By comparison the effect of people erroneously believing that all CD players offered 'Perfect Sound Forever' (for those of us around in the early 80s), as the theories and graphs and Tomorrow's World all claimed, was unfortunate but didn't kill anyone.
    Steven Toy likes this.
  14. TheFlash

    TheFlash Superhero of Sound

    I suspect Keith thinks that his reality is THE reality.
  15. NickofWimbledon

    NickofWimbledon Well-Known Member

    @Purité Audio - fair comment, esp on spikes.

    As I said, it is possible the degree of commonality in views came from them peeking at what I was doing (as i say, not properly 'blind') and lying about it, but it doesn't seem likely. They certainly weren't doing that most of the time and one of the two would have had little idea what I was up to in the corner anyway. With only 3 of us and a couple of dozen records tried, the sample size is not ideal either.

    FWIW, I am annoyed by results that make no sense to me - like putting rubbery feet under a box whose only moving parts are electrons. I wanted the smug feeling from debunking some 'snake oil' that had fooled so many. However, when that clearly was not the result of testing, I admitted it. I even owned up on the Naim website whose members seemed split between encouraging me to try what they have done themselves and 'knowing' that the stuff could not work and so never needing to try using their ears to check.

    As I think Keynes said: 'When I get new facts, I change my views: what do you do?"
  16. Purité Audio

    Purité Audio Trade: Purite Audio

    Some years ago a company which manufactures laboratory isolation equipment ( not foo ) visited and measured with a three plane accelerometer the amount of structural vibration transmitted from an extremely large pair of loudspeakers playing extremely loudly.
    Essentially turntables may benefit from broadband structural isolation, but you still have to contend with airborne transmission, if you really want to isolate site the turntable in another room.
    @nick comparisons ‘must’ be unsighted.
  17. NickofWimbledon

    NickofWimbledon Well-Known Member

    Hi Keith,

    I think we agree there are lots of compromises here.

    I have a bouncy floor.

    We were doing the tests to a standard that gave a good guide to us, not for independent verification.

    Room differences are hugely important, but there are limits to what I am prepared to do - no rewiring of the house, no removing reflecting surfaces or putting sound-deadening on the ceiling, no removing all other electronic from the listening room, or facing East and standing on one leg to listen....

    I am unwilling to put the turntable on a concrete floor in a different room, with rack in a second room and speakers/ sofa in a third.

    My council do not permit me to close the road so that I can cut out the shaking & noise of buses. The same is true at the Royal Albert Hall - RBK&C are most unreasonable about this.

    My ears are not great and 57 years old - and we all know what that does to higher frequency hearing.

    While one of my listeners knows little of hi-fi stuff and 'doesn't believe in it', the other is used to spending time in a studio, arguing over monitors, putting coffee on the mixing desk (if analogue) and so on. We made it as clear as we could as a test, knowing that we were not doing for other people, but sticking blindfolds on both for several hours would (among other things) have made using notepads tricky.

    From your stance, you must have had some wonderfully lovely chats with Max Townshend and Russ Andrews over the years!
    Dark Lord likes this.
  18. Steven Toy

    Steven Toy Accuphase newbie

    Keith has chosen the doctrinaire objectivist as his niche in the competitive audio market.
    NickofWimbledon likes this.
  19. Sue Pertwee-Tyr

    Sue Pertwee-Tyr neither here nor there

    Not sure I’d go along with this. Most electronic equipment is microphonic to some degree, even if only a minuscule effect. But if that minuscule effect raises the noise floor by a few dB, which for noise at -110dB wouldn’t require much voltage at all, then even if the noise remains at sub-audible levels, it can have a detrimental effect in sound. This because some of the output of the amp, say, is applied to amplifying that noise rather than the signal. Noise doesn’t have to be audible in order to be parasitic and detrimental.
  20. NickofWimbledon

    NickofWimbledon Well-Known Member

    Sue Pertwee-Tyr likes this.

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