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Speaker De-coupling

MattHooper

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This actually reminds me: I am pretty much automatically skeptical of tweaks, audiophile footer tweaks especially. You see many making what seem to be absurd claims of footers and isolation making sonic differences even under CD transports! The "everything makes a difference" subjective school of thought.

Turntable isolation makes sense to me, in the right conditions.

But I wondered about tube amplification. Many speak of microphonics, vibrations of the tubes I think, possibly altering the sound.

Is this a plausible effect if, say, you have tube amps in the same room as the speakers?

Or on a wood floor with people walking around a house (my tube amps have been on the floors sometimes)?

Or are there tube microphonics that can occur simply from the amp itself in operation? (I think this is the rational some have for putting those rubber rings on the tubes).

I can only say that for the heck of it I put my tube pre-amp on a few left over materials, footers, even isoacoustic pucks since I had them. I don't note any audible difference at all vs just sitting on it's wood shelf.
 

Thomas_A

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Thanks Keith.

As it happens, my turntable, along with my amplifiers and source gear, are actually in a separate room from my listening room (down the hall a little bit). Originally I wondered if this would be unworkable for using a turntable, after all it makes sense ergonomically to have it in the listening room.

But it turned out just fine. I've found that when I lower the arm, by the time the music actually starts playing I'm usually in my seat. It would be essentially the same if the turntable where in the room as I'd have to get up and down when I wanted to change LPs or tracks. So it's been no hassle at all, and some peace of mind in terms of air-born resonances from the speakers.

(Though someone, I forget on this website or another, measured the feedback effect on the signal with turntables from the speakers, and said it can slightly alter the sound in a way some people like).

I did a test once with lid on or off.
 

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Frank Dernie

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Depending on the floor construction, the position of the speaker on it, the frequency response of the speaker and the local masses and stiffnesses it is scientifically inevitable that there will be an audible difference between spike coupling a speaker to a floor and using wide band (ie down to 20Hz) isolation.

Some floor types may make the difference negligible and the sort of relatively lightweight mini monitors most people have probably won't have the potential to make a difference but with big floor standers on a suspended wooden floor the difference will be marked.

No, I haven't measured it though.

I do know however that if I listen to a recording of a microphone positioned at my listening position it isn't picking up what I "hear", presumably because it is incapable of "listening through the room" whereas I can not avoid doing so.
 

dfuller

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This actually reminds me: I am pretty much automatically skeptical of tweaks, audiophile footer tweaks especially. You see many making what seem to be absurd claims of footers and isolation making sonic differences even under CD transports! The "everything makes a difference" subjective school of thought.

Turntable isolation makes sense to me, in the right conditions.

But I wondered about tube amplification. Many speak of microphonics, vibrations of the tubes I think, possibly altering the sound.

Is this a plausible effect if, say, you have tube amps in the same room as the speakers?

Or on a wood floor with people walking around a house (my tube amps have been on the floors sometimes)?

Or are there tube microphonics that can occur simply from the amp itself in operation? (I think this is the rational some have for putting those rubber rings on the tubes).

I can only say that for the heck of it I put my tube pre-amp on a few left over materials, footers, even isoacoustic pucks since I had them. I don't note any audible difference at all vs just sitting on it's wood shelf.
This would only make a difference if the tubes were wildly microphonic - in which case they would just be squealing.
 

Thomas_A

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Just wonder if there is an interest of more measurements? I have this one lying around.
124FF9CE-548B-4D6C-834B-17BDEDB83281.jpeg
 

Tim Link

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Depending on the floor construction, the position of the speaker on it, the frequency response of the speaker and the local masses and stiffnesses it is scientifically inevitable that there will be an audible difference between spike coupling a speaker to a floor and using wide band (ie down to 20Hz) isolation.

Some floor types may make the difference negligible and the sort of relatively lightweight mini monitors most people have probably won't have the potential to make a difference but with big floor standers on a suspended wooden floor the difference will be marked.

No, I haven't measured it though.

I do know however that if I listen to a recording of a microphone positioned at my listening position it isn't picking up what I "hear", presumably because it is incapable of "listening through the room" whereas I can not avoid doing so.
I think this is hitting on the main issues. Big floor standers on a suspended wooden floor can actually act as vibration dampers for the floor when they are suspended on springs. I don't think it's so much about cabinet vibrations being transmitted to the floor, but sound pressure level in the room that's exciting the floor. It might be that the speakers don't have to be all that big and heavy to effectively damp the floor in some situations. Suspending the equipment rack and other furnishings in the room may also be helpful if the floor is vibrating. Portions of the floor that are toward the middle of the room, furthest from a support pillar would be prime targets. It occurs to me that I could suspend myself in my listening chair since I'm sitting in the middle of the room. I'd have to learn to sit still. Might be kind of fun, or highly annoying.
 
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