Constrained Layer Damping to Absorb Bass

[AllenB]

Constrained Layer Damping is about preventing vibration and resonance.

Ah, but it's not about preventing resonance of the wall panels. This is about room modes. The wall panels are not some random resonance that needs to be killed. Their movement is working for us, not against. It doesn't matter if you can hear them from outside the room for this purpose (and you will if it does its job ).

Imagine they were completely solid. This way they wouldn't move. Modal reflections would be completely contained and undamped.

to move independently of the floor for a very small distance.

You seem to be saying that this small movement performs a job without undoing the primary effect.

 

[sondans]

Allen,
I did not consider critical damping, and to be honest did not know what it was until I did some reading on it. It seems that critical damping would be best and that over-damping would be better than under-damping. Since damping ratio is inversely proportional to mass and stiffness, that leads me to believe that low stiffness and low mass would be desirable for what I am trying to accomplish. Does that make sense to you?

Unfortunately I'm not proficient in reading electrical diagrams so I was unable to understand what point you were trying to get across.

 

[AllenB]

leads me to believe that low stiffness and low mass would be desirable for what I am trying to accomplish. Does that make sense to you?

Also that two different Q resonances (eg, otherwise same frequency) can be brought to behave similarly if you introduce the appropriate amount of damping in each case.

Earl says more damping is better, and suggests some techniques for maximising it. He mentions microspheres. Otherwise he uses some kind of gypsum board.

Looked at another way this is a suggestion on what qualifies as appropriate stiffness and mass.

 

[kach22i]

No matter what, your bass will be venting up the stairwell and into the rest of the house.

So you might ask yourself what the point is.

 

[ASCTim]

No matter what, your bass will be venting up the stairwell and into the rest of the house.

So you might ask yourself what the point is.

The bass venting up the stairwell is helpful, but a lot of bass can still get trapped for a long time between parallel surfaces before it can leak out the stairwell, so the damped wall construction helps with bass clarity, as do bass traps, even if they can't cure mode cancellations.