Another fun test? Vibration damping

[Yannzola]

It might be interesting to know if any measurable difference can be found jitterwise on either the analog or digital outputs when the Squeezebox is isolated (as much as possible) from physical vibration... Some hi-fi manufacturers swear that "floating" their boards has a noticable positive imapact (NAIM for one)... and god knows most audiophiles have at least played with spikes/cups/rubber feet/inner tubes... not to mention =much more= esoteric (read: expensive) vibration damping rigs under their transports/amplifiers/PSU's/etc.
I've never seen any hard numbers for these "improvements"... although I =have= heard the difference these isolators can make.

Here's an (basic) idea for a possible series of tests. Measure jitter while the device is idle; while its playing (no ambient sound - ext. amplifier off); playing (full rockin'/concert level sound). Then the same series of tests with some sort of vibration isolation in place.

Anyone else interested?
y.

[Neil Davidson]

>
> It might be interesting to know if any measurable difference
> can be found jitterwise on either the analog or digital
> outputs when the Squeezebox is isolated (as much as possible)
> from physical vibration... Some hi-fi manufacturers swear
> that "floating" their boards has a noticable positive imapact
> (NAIM for one)... and god knows most audiophiles have at
> least played with spikes/cups/rubber feet/inner tubes... not
> to mention =much more= esotic (read: expensive) vibration
> damping rigs under their transports/amplifiers/PSU's/etc.
> I've never seen any hard numbers for these "improvements"...
> although I =have= heard the differenece these isolators can create.
>
> Here's an (basic) idea for a possible series of tests.
> Measure jitter while the device is idle; while its playing
> (no ambient sound - ext.
> amplifier off); playing (full rockin'/concert level sound).
> Then the same series of tests with some sort of vibration
> isolation in place.
>
> Anyone else interested?
> y.
>

Personally I can see the point with a CD transport, but with pure
electronics without moving parts, hmmmmmmm........

[Yannzola]

>

Personally I can see the point with a CD transport, but with pure
electronics without moving parts, hmmmmmmm........

Yup... you'd think so, and I agree. But lot's of folks =swear= they can hear improvements by isolating things like solid-state amplifiers, power sources, etc... I'm curious if this kind of tweak actually has a measurable effect, or if it's all placebo.

[cliveb]

Yup... you'd think so, and I agree. But lot's of folks =swear= they can hear improvements by isolating things like solid-state amplifiers, power sources, etc... I'm curious if this kind of tweak actually has a measurable effect, or if it's all placebo.
And there are folks who swear they can hear improvements by placing little pieces of rainbow-coloured foil on their equipment; or by storing bottles of "demagnetised water" under the sink in the kitchen; or by inserting extra sheets of paper into books that are in the same room. (Honestly, I'm not joking - look for the writings of people like Jimmy Hughes and Peter Belt). Life is too short to properly test nutcase theories like these.

Of course, the idea that vibration can affect solid-state electronics is nowhere near as crackpot as those mentioned above, but IMHO it's still in the realms of "not plausible enough to be worth bothering about".

[bludragon]

Well, it would seem to me that as record decks were sensitive to vibration, this idea then carried over to cd players (which may be effected, due to the moving parts) and then onto other audio equipment.

However, I did read somewhere once that capacitors can be sensitive to vibration - movement causes their electrical characteristics to alter slightly, and that tantalums were particularly effected. So who knows?

[Music Machine]

Vibrating anything that is conducting alternating current causes that thing to interact with the magnetic field it is itself generating. Non-linear spectral contamination is the result. However small, it is distortion.

Regards,
Music Machine

[Yannzola]

Vibrating anything that is conducting alternating current causes that thing to interact with the magnetic field it is itself generating. Non-linear spectral contamination is the result. However small, it is distortion.

Regards,
Music Machine


So I take it a battery powered unit would suffer less? Is that right? Interesting...

[pfarrell]

On Sat, 2005-10-08 at 17:37 -0700, Yannzola wrote:
> Music Machine Wrote:
> > Vibrating anything that is conducting alternating current causes that
> > thing to interact with the magnetic field it is itself generating.
> > Non-linear spectral contamination is the result. However small, it is
> > distortion.

> So I take it a battery powered unit would suffer less? Is that right?
> Interesting...

All audio signals are alternating current.
Whether this is important or not is another issue altogether.

--
Pat
http://www.pfarrell.com/music/slimserver/slimsoftware.html

[cliveb]

Vibrating anything that is conducting alternating current causes that thing to interact with the magnetic field it is itself generating. Non-linear spectral contamination is the result. However small, it is distortion.
OK, fair point in theory. The question is, at what level is this distortion? When you consider that we're dealing with signals at a few tens of millivolts and very low currents, the generated magnetic field will be extremely small. And therefore the induced distortion will be similarly small. It would not surprise me to hear that the induced distortion is down a long way below -100dB, and therefore masked by plenty of other noise and distortion sources. Does anyone around here have the necessary maths skills to work out the actual figures?

[Music Machine]

The distortion will be small, no doubt. Still, it might be audible. The signal path is long and every inch of it is vibrating. When people reported hearing a change by isolating CD players from the shelf I tried it too. The change was quite noticeable. Then I tried it on a power amp and heard a similar though smaller change in the sound. I don't really know why it happens. It's a result looking for an explanation. Theory is all we have right now. Many who read this will now theorize I'm a nut case. That theory may prove to be true, but it won't change the audibility of isolation. YMMV

Regards,
Music Machine

[Yannzola]

...Then I tried it on a power amp and heard a similar though smaller change in the sound. I don't really know why it happens. It's a result looking for an explanation.

I've had similiar experiences.... which is why I suggested doing an empirical test. As far as I know... no one has published anything like this before. IMHO The results would be interesting either way (noticable jitter or not).

Come on Dean and Sean... do it for science! ;)
y.