Vibrating speakers

Ahh, you're confusing and conflating several related yet different things. Yes the speaker vibrates. That's what we hear- vibrations. But there's really only one part of the speaker we want to hear vibrating: the cone. 

But playing music the cone goes in and out, which causes the whole speaker cabinet to vibrate opposite that. The speaker is a lot more massive and so it moves less but it still moves some and to the extent it moves it sucks the dynamics and life out of the music. This is one part of why physically bigger more massive speakers project a bigger more lifelike sound.

But its not just the whole speaker cabinet vibrating back and forth. Driver vibrations travel all through the whole speaker cabinet causing every single part to vibrate. All the wires and crossover parts, all the side front and bracing, all of it. None of which we want to hear. All we want to hear is the cone. But even the cone itself is resonating and vibrating in ways we do not want to hear.

So its all vibrations, only some of which we want. Kind of like the posts around here. You just need to figure out which are signal and whose are noise.

Enter speaker isolation. Hel-loo speaker isolation!

Imagine making a speaker attempting to get the same sonic behavior as a violin. Well, that's great, but how do you deal with a drum, a sax, the human voice, bells?  Yes, some instruments are made of wood, but many are not.

The speakers should not add any unintended sonic signature. I say "unintended" because some speakers have a house sound which is achieved through a variety of means, and I imagine cabinet construction is one of them.

Ideally, these vibration controls occur:

• The cabinet does not vibrate
• The cabinet does not transmit vibration to the floor, which then re-radiates into the room
• The speaker itself is fixed in all three dimensions

The last one is why adding mass to the top of a monitor can help.


Having said this, there is some research related to controlling, instead of eliminating, vibration altogether. I don't remember much about it, but it's a compromise brought on by the need to create affordable and relatively small and lightweight systems.