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It's possible to purchase a big stone block to stand your hifi amplifier on, and the vendor claim is that it improves the audio performance.

Is there any evidence that doing something similar with a synthesizer or amplifier would make it sound better? Or moving slightly wider than that, is there evidence that adding weight to a musical instrument, like a grand piano or a trombone or whatever, improves it noticeably?

I have to say I'm dubious of the claimed hifi improvement, but I'm trying to ask with an open mind.

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    People will buy anything if someone persuades them it's "because physics", or even "because quantum" if you fall for the really, really expensive scams. If amps were so susceptible to vibration, we wouldn't be able to put them in every car on the planet. Most of this 'audiophool' stuff is just so much horse-apples.
    – Tetsujin
    Commented Apr 27, 2022 at 13:05
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    Pretty sure there’s no evidence that buying such things for hifi equipment makes a difference. Working studios can’t afford to waste the money. Then again, I’ve read that gateway mastering has or had speakers with cabinets made from marble (or something like that). Commented Apr 27, 2022 at 14:55
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    I'm guessing the vendor is Goop, Inc. Commented Apr 29, 2022 at 14:03
  • Just watched this video youtube.com/watch?v=n02tImce3AE&ab_channel=JimLill which tests related claims perpetuated by electric guitarists. Commented May 8, 2022 at 17:51

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Well, things like rock blocks can have an effect on things that are moving a lot (like loudspeakers) by anchoring them well, or on things that are definitely not supposed to move a lot (like record players).

In the former category I actually have a rather heavy "sound bar" with tiny speakers that have an oblique axis and a rubberised bottom. I suspect that this turns the average wooden table into a substitute low frequency woofer (regular frequency range starts at 100Hz or something like that) while a rock block would remain inert.

With regard to record players: the problem with them is of course microphonics: picking up vibrations and feeding them back into the sound chain.

Vacuum tubes often suffer from microphonics, and some ceramic capacitors tend to be microphonic as well (you get noise in audio circuits they are a part of when tapping them). Excessive microphonics can be considered a part deficiency (like with some tubes), but at least with some capacitors, they can be inherent to the device. A good audio device engineer would avoid such parts in susceptible circuits.

As an amplifier enhancement, the main purpose of a slab of rock would appear to balance the weight loss it causes in the purchaser's wallet. The money would likely be better spent by paying someone for tapping every component in the amp and exchanging everything that manages to elicit a response with a part of a non-microphonic variety. That may be tedious but I doubt that it would exceed the cost of HiFi rocks even with a generous allotment for parts and work time, and it's likely quite more effective in those rare cases where the rock would provide some discernible difference.

With regard to adding weight in some form to a musical instrument: of course it makes a difference since it changes its resonant properties. Even an electronic keyboard (probably more so with hammer action) will benefit from solid support rather than a wonky stand, albeit in that case the advantages will be more of mechanical nature rather than sound. And when we are talking about electric instruments (like a Fender Rhodes or a Hammond organ) there are mechanical parts involved with their sound creation that can both exhibit microphonics and be adversely affected by bad mooring sapping sound energy.

But for amps? At best, voodoo (but probably visually aesthetic voodoo adding to the enjoyment), at worst, a bad bandaid for badly designed or deficient equipment.

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  • Rhodes have moving parts - hammers on tines - but Hammond organs..?
    – Tim
    Commented Apr 27, 2022 at 14:04
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    Hammond organ generates sound using motorised spinning tonewheels. Lots of moving parts. Commented Apr 27, 2022 at 14:59
  • Speakers don't move much at all; that's more 'audiophool' horse-apples. Put your hand on the side of any half decent hifi/studio speaker & you won't feel a thing.
    – Tetsujin
    Commented Apr 27, 2022 at 15:11
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    I wouldn't be so sure about the speakers not vibrating. Genelec usually does their homework and their speakers are sold with a vibration isolation thing. On the other hand, I have a pair of Focals that clearly vibrate. They sound better without any isolation under them, and indeed Focal markets expensive stands that they can be bolted to. There is a lot of hi-fi nonsense out there but somehow you managed to pick the few examples that somewhat grounded in reality :)
    – ojs
    Commented Apr 28, 2022 at 9:57
  • @ojs - my old Gennies just sat on stands, no 'isolation' to speak of, I can't say I ever tested the 'hand on the side' thing, but my dynaudios don't vibrate perceptibly, nor my Linns on the HiFi in the lounge. The Linns, of course, are bolted to posh isolating stands with spikes… see, I did buy into the hype ;)) [In my defence, the stands are a part of the speaker design, not a DIY add-on]
    – Tetsujin
    Commented Apr 28, 2022 at 10:19
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For anything that does not move air, you just want to make sure it is placed on solid foundation so it cannot fall off. For things that consume power, you also want to make sure that they get enough air space to cool themself (see the respective manuals for how much free space is needed).

For things that move (like speakers or vinyl players) you can consider decoupling them from resonators, so their capability to create unwanted sound is reduced to a minimum. The decoupling reduces the mechanical amplification. In fact, you want to hear the music, not the machine noises.

In addition, speakers on an stand can act as a pendulum and when emitting air waves to the front (or back) they experience a very small counter-force in the opposite directions which largely does not matter. However you might be unlucky and find a frequency in your speaker's output that matches the self-resonance of the speaker-stand-pair. In this case, the speaker and stand might start to oscilate (hardly noticable) and can deform the frequency response (Doppler effect). To avoid this oscilation, you can make the stand as hard to move as possible (by increasing it's mass or fixating it). However, these effects are usually too small to notice and often can hardly be measured.

To sum up:

  • For speakers: it can help, but is hardly of noticable difference
  • For moving parts: just avoid mechanically amplifying oscilations
  • For powered devices: make sure they stand secured and have enough space around them

In general: Do not optimize something, you do not notice. Measure and compare. Get a baseline without optimizations so you can compare to it.

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Audiophools mount their speakers on heavy, rigid stands, sometimes going to the lengths of filling them with sand or coupling them to the wooden floor beneath with spikes. Yeah, I guess that makes sense. Then, just under the actual speaker box they place a special vibration-absorbing mat, to decouple it from the stand! And that's at the less lunatic end of audiophoolery!

We used to play vinyl through pickups mounted in ultra-lightweight headshells. I always thought my records sounded better after adding some mass - typically a lump of plasticine. More inertia - firmer base for the vibrating needle, right? But that wasn't the Right Way.

Then there's Magic Power Cables - like the last metre of cable in the miles-long path from the generating station was going to make a significant difference. Lots more idiocy here, if you want a laugh.

https://www.russandrews.com/

Amplifiers should be placed on a firm, flat surface. Because if they fall off, it can be expensive. That's all.

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  • For what it's worth, vinyl player do have a low frequency cutoff and some resonance above it. Heavier headshell lowers the frequency but increases resonance Q. The frequency should be below hearing range and musical content but some ultralight headshell could mess it up.
    – ojs
    Commented Apr 27, 2022 at 15:04

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