Do vibrations have an impact on solid-state amplifiers' sound quality?

[JustAnAudioLover]

Hi there!

I recently went to a reputed audio shop, which is specialized in both Hi-Fi and Home Theater equipment.

I spoke a lot with the seller, which clearly knew a lot of things about audio. But then at one point he explained to me that (mechanical) vibrations had an impact even on solid-state amplifiers' sound quality. He was 100% sure of what he said, even when I told it seemed weird to me.

He then proceeded to explain that some high-end amplifiers from reputable brands, which sell for thousands of dollars, have cases that don't handle vibrations correctly, and putting some weights on top of the amplifier or stuffing it with anti-vibration material helped a lot with reducing vibrations and immediately improved audio quality by a noticeable margin. It's one of the main reasons why he doesn't sell these brands in his shop.

Clearly it wasn't to try to sell me anything, it was just his opinion on the subject (well, certitude). But this seems really weird to me, so my question is:

Can vibrations have a real impact on solid-state amplifiers' sound quality?

If someone could enlighten me on the matter, that would be great
Thanks!

 

[Roland68]

Hi there!

I recently went to a reputed audio shop, which is specialized in both Hi-Fi and Home Theater equipment.

I spoke a lot with the seller, which clearly knew a lot of things about audio. But then at one point he explained to me that (mechanical) vibrations had an impact even on solid-state amplifiers' sound quality. He was 100% sure of what he said, even when I told it seemed weird to me.

He then proceeded to explain that some high-end amplifiers from reputable brands, which sell for thousands of dollars, have cases that don't handle vibrations correctly, and putting some weights on top of the amplifier or stuffing it with anti-vibration material helped a lot with reducing vibrations and immediately improved audio quality by a noticeable margin. It's one of the main reasons why he doesn't sell these brands in his shop.

Clearly it wasn't to try to sell me anything, it was just his opinion on the subject (well, certitude). But this seems really weird to me, so my question is:

Can vibrations have a real impact on solid-state amplifiers' sound quality?

If someone could enlighten me on the matter, that would be great
Thanks!

Where could these vibrations come from?
We don't normally have vibrations in our living spaces that need to be decoupled.

 

[Mart68]

Where could these vibrations come from?
We don't normally have vibrations in our living spaces that need to be decoupled.

There will be airborne and structure-borne vibration, everything is moving to some degree.

The idea it effects sound quality of an amplifier has no basis in fact, as far as I'm aware. I recall March Audio tested this some years ago with an amp and a DAC and found no difference to the output of the devices even when subjected to earthquake levels of vibration.

 

[Petrushka]

Just observing that rocket launches do seem to affect video transmission.

Is there anything in a home that produces equivalent vibration.

 

[Doodski]

Some components can be microphonic and when the device sustains a impact they make noise.

 

[Pareto Pragmatic]

I recall March Audio tested this some years ago with an amp and a DAC and found no difference to the output of the devices even when subjected to earthquake levels of vibration.

Which makes sense.

I usually try to rephrase such questions into the form of, "What would it take to have an effect?" Something loose that resonates at a frequency that the room produces might do it. Say a loose speaker connection, a solder connection that is not quite solid but not bad enough to affect things when it is not vibrating, maybe. But those are from flaws, not from a properly functioning amp.

I think the advice comes from two sources. First, the placebo effect leading to overconfidence. Second, there are issues with some things, like turntables, and that becomes generalized.

 

[ivayvr]

If that was possible for solid state equipment, all loudspeakers would sound bad. Especially active speakers and sub woofers.
Currently, when all or most components are SMD, how is that even possible (vibration)?

 

[JustAnAudioLover]

If that was possible for solid state equipment, all loudspeakers would sound bad. Especially active speakers and sub woofers.
Currently, when all or most components are SMD, how is that even possible (vibration)?

The seller's argument was that it doesn't make things sound bad (unless the case is not correctly built) but it has a negative impact on the sound quality.

 

[Ropeburn]

Ah yes, the famous microphony. It is indeed a real physical effect, but as always the question is how much it matters. With modern solid state electronics it's a bit like the skinning effect in cables: real, but completely irrelevant. Still good enough and welcome for selling snake oil like isolation feet, expensive audio racks, and cable risers.

 

[JustAnAudioLover]

Ah yes, the famous microphony. It is indeed a real physical effect, but as always the question is how much it matters. With modern solid state electronics it's a bit like the skinning effect in cables: real, but completely irrelevant. Still good enough and welcome for selling snake oil like isolation feet, expensive audio racks, and cable risers.

So what you're saying is that there is an impact, but below the threshold of what a person can hear? If so, how does the vibration impact the electronics exactly? (genuinely curious)

 

[BeeKay]

We used to have a test facility (shock stand) to certify products we build to be used in NPPs and submarines. I am almost certain lots of home HiFi gear would have been in serious trouble.

 

[Mart68]

The seller's argument was that it doesn't make things sound bad (unless the case is not correctly built) but it has a negative impact on the sound quality.

It's something that's commonly accepted in audiophile circles, as is spending thousands to combat the 'problem'. That's probably where he's got the idea from.

Of course people perceive a difference when they stick their amp on their new ten grand support system. As usual, it's just down to a failure to do a controlled comparison, combined with wanting to believe.

 

[rdenney]

Yes, some components can be microphonic, particularly capacitors with soft dielectric materials, or capacitors with high-kappa dielectrics. Most don't create any effect unless you actually tap them. It's not that hard to minimize the effect, and in any case it's easy to avoid the problem with respect to sound energy either by construction methods or by choice of components.

Rick "can sometimes hear the effect when tapping around in active circuits" Denney

 

[Ropeburn]

So what you're saying is that there is an impact, but below the threshold of what a person can hear? If so, how does the vibration impact the electronics exactly? (genuinely curious)

The theory is pretty simple: a moving conductor in a magnetic field generates a voltage (and therefore a signal), and a conductor with current flowing through it generates a magnetic field.

So, in theory, any working electric component that moves (for example vibrating from loud music) is a microphone to a degree.

It's just that in most realistic constellations, this effect is so miniscule, it not only completely vanishes in the device's inherent noise floor, it's also somewhere between difficult and impossible to measure at all and couldn't be any further from audible. And thus, utterly irrelevant.

Microphony used to be more of a problem with tubes for example, because they're more suspectible to it than transistors are, for mechanical reasons.

 

[KL....]

I spoke a lot with the seller, which clearly knew a lot of things about audio. But then at one point he explained to me that (mechanical) vibrations had an impact even on solid-state amplifiers' sound quality. He was 100% sure of what he said, even when I told it seemed weird to me.

He then proceeded to explain that some high-end amplifiers from reputable brands, which sell for thousands of dollars, have cases that don't handle vibrations correctly, and putting some weights on top of the amplifier or stuffing it with anti-vibration material helped a lot with reducing vibrations and immediately improved audio quality by a noticeable margin. It's one of the main reasons why he doesn't sell these brands in his shop.

As you mentioned, if you like a component, and it is suffering from resonance effects, then if the resonance effects cannot be controlled through diffusion methods (rather than dampening methods/easy to over dampen although the least amount/a little dampening is ok, isn't it?), it could/should be suggested to not purchase this component, couldn't it? This is good advice, isn't it?

 

[Purité Audio]

Clearly the salesman a, didn’t know that much about audio or b, does know but was still trying to sell you something.
Keith

 

[Mart68]

Clearly the salesman a, didn’t know that much about audio or b, does know but was still trying to sell you something.
Keith

when I sold cellphones one of the tactics we would use to shift the customer's focus onto the models we were trying to move was to instil a bit of doubt in their mind about the ones they were interested in.

 

[Purité Audio]

Can you teach me those tactics I am a really hopeless salesman, frequently I manage to persuade a prospective customer not to buy anything, much to my wife’s despair!
Lately I have taken to only answering sales enquiries in the office to avoid the advanced sigh/eye rolling.
Keith

 

[KL....]

when I sold cellphones one of the tactics we would use to shift the customer's focus onto the models we were trying to move was to instil a bit of doubt in their mind about the ones they were interested in.

Can you teach me those tactics I am a really hopeless salesman, frequently I manage to persuade a prospective customer not to buy anything, much to my wife’s despair!
Lately I have taken to only answering sales enquiries in the office to avoid the advanced sigh/eye rolling.
Keith

You know those tactics could be termed disinformation (deliberately missing information to create doubt/fear with intent to justify harmful means or simply harm) and even bordering on malinformation (maliciously deliberately missing information to create doubt/fear with intent to justify harm/malicious harm), doesn't it? Misinformation is missing information with intent to inform but not with intent to harm and to be helpful but if conveyed in a manner, 'do as I say not what I do', which is a 'Wise in your own Eyes manner' then this escalates the intent to harm/hinder and to the level of disinformation, doesn't it?.

Clearly the salesman a, didn’t know that much about audio or b, does know but was still trying to sell you something.
Keith

There could be c. does know and is endeavouring to be helpful to assist you to make an informed choice. But, we will not know until we know the entire context/intent of the discussion, will we?

 

[alex-z]

I spoke a lot with the seller, which clearly knew a lot of things about audio. But then at one point he explained to me that (mechanical) vibrations had an impact even on solid-state amplifiers' sound quality. He was 100% sure of what he said, even when I told it seemed weird to me.

Can vibrations have a real impact on solid-state amplifiers' sound quality?

Doubtful the salesman actually knows a lot about audio. Like most technical fields it is easy to have convincing opinions which fall apart in a conversation with an actual expert.

As other comments explained, microphonics do exist, particularly with tantalum capacitors. However their use in audio circuits is rare, and usually not audible even when that mistake is made.

The only time I have ever proved an amplifier chassis disturbed sound quality was when I played bass so loud it rattled the shell on an AV receiver. Yamaha forgot threadlocker and they worked loose after 20 years. 30 seconds with a screwdriver to fix.