--- In DTXpress@yahoogroups.com, "anttipi" <anttipi@y...> wrote:
> Yeah, by vibrations I meant those (very low?) frequencies that the
> vibrating rack and bass pedal send through a concrete floor. By
> ordinary "sound waves" I meant the sound (somewhat higher
> frequencies) YOU hear in your apartment when you hit the pads. The
> terminology was wrong, I admit, but I was just trying to illustrate
> my point.
>
> My logic (which once again may be at fault) says the softer the
> platform material, the better it eliminates the kind of structure-
> borne vibrations we are talking about here. The harder the
material,
> the better the vibrations are transmitted further onto the floor.
Now
> I'm no expert in soundproof mats - which of course work in their
own
> specific ways - but at least I know they are quite a bit more
> expensive than foam.
As you guys say, it's all sound waves and vibrations, and the long
waves of those bass frequencies can cover some ground. Foam will
absorb sound; people frequently use it to eliminate standing waves
and improve a room's response. But it will not eliminate stray noise.
Sometimes absorption is enough to satisfy the neighbors--especially
when unamplified e-drums are the problem--sometimes not. The only way
to eliminate noise outside the desired confines to to add structure
and to keep the possibilities of it propagating vibration as low as
possible. I'm no expert (far from it), but I've heard of double
walls, fiberglass insulation, pressboard, plexiglass, and judicious
caulking all coming into play to create mass, weight, rigidity,
distance, and absorption. Any open spaces between joints and layers,
however, could cause the structure to vibrate (like a speaker) and
defeat the purpose. So any binding has to be tight, and the thicker
the intervening area is, the more the waves will dissipate. E-drums
don't create any particular low frequencies, but the thump of the
kick pedal through a floor can be annoying to others. Decoupling it
from the floor with as thick a carpet as possible and/or raising it
up on an another absorbent platform might be all an apartment dweller
can do--in conjunction with diplomacy, that is.
Ed
