DIY speaker isolation base for a wood floor

Pushing up and down on the springs when they’re set up is a good way to measure the resonant frequency Fr of the system. With a stop watch count the number of complete up and down cycles and divide the total by 10. If properly set up you should be able to get down to 2-3 Hz (cycles per second).

I like granite slabs a lot because they are very stiff against bending forces. But I eschew rubbery things in the context of isolation. I suggest very hard cones for mounting and stay away from Sorbothane, cork, rubber, etc. as soft Springy materials store or block energy and interfere with the actual springiness of the springs. Energy should be allowed to exit the system as rapidly as possible. 

audiozenology "Wood floor. Assume somewhat springy? ... then usually better to isolate"

Before isolation I would try to load with mass first it is much more likely to work in that type of situation when using a Music Reproduction System speaker.

Blueranger,


Just using springs will be wobbly. If you are targeting 2-3hz resonant on the springs, then most higher frequencies will not be transmitted .. it flops.  If you add dampening in parallel with the spring (ie sorbothane), then you can keep a low resonant frequency, but damp oscillation. Some higher frequencies will now pass (still highly attenuated), but the system will not feel nearly as "floppy" as the resonances are damped.


Wrt Clearthink's post on just adding mass, all that does is change the resonant frequency of the speaker/mass and spring (i.e. your floor). The spring constant, i.e. your floor does not change. As I mentioned above, a wider stiff base (ie your granite bases) does change your floor interface which may transfer weight closer to the joists which will change your spring constant (floor).


Where Geoff and I agree is on a spring loaded floor isolation is better. I prefer damped as that damps out cabinet vibration and isolates from the floor.

Trying to damp spring oscillation is a fool’s errand. For one thing they’re not really oscillating. Where did you get that cockamamie idea? The springs only move when you push down on them. Hel-loo! My springs and probably all springs sound best with no damping. This is not rocket science, folks. You’re making a mountain out of a molehill. Give the the right spring and I’ll isolate the world. audiozenology is trying to make this into some sort of debate. There is no debate here. This is an obvious case of too many cooks spoiling the broth. And don’t flatter yourself. We don’t agree on anything.

If you push down on a mass that’s on a spring and then let go it will oscillate. it’s not a sustained oscillation but it most definitely oscillates. many of us have done this experiment on our car when the shock absorbers were at the end of their life.


I am not trying to turn this into a debate because there is no debate. When you push a mass on a spring it will oscillate at a defined frequency. It won’t sustain those oscillations but it will oscillate. There is no debate it does that. That is literally high School physics. The op doesn’t like his speaker is being floppy. the way to eliminate that floppiness while still having a high level of isolation is to a dampening. A game this is not a debate that is simple fact. There are trade-offs with adding that dampening as I pointed out. That is not a debatable item that is simply fact.