chris wrote:

Late last year I posted a question ,on isolating my sub to prevent
annoying the neighbours.

Well I finally got a round to testing today.

With a Platform of 2 * 18mm layers of MFD with thin silicon rubber
interlayer glued with PVA and with sorbothane feet.
I got a reading of 70 db on my rat shack meter in the downstairs flat
from a 100 db in the listening room I was playing the trance dance
scene from the matrix revisited

Then added another layer: of duck rubber non slip router-matt/
drawlinner matting and another 18mil mdf sheet : that got it down
another 6ish or so db's .
Then I put partly inflated innertubes on the platform and another MDF
sheet between them and the sub (to stop the spikes rupturing the
tubes).

This just a sandwich of innertubes and MDF?


Got it down to barely flicking the needle downstairs (just 50db's) it
was barely audible and that was with a spl of 110db's in the listening
room.

Impressive result. Extremely impressive result.

You're sure of what you measured?
It shows a 60dB attenuation due to the interruption of *transmitted* energy
from the sub cabinet to the floor, the *air* transmitted component being a
scant 50dB remaining?

_-_-bear



I would like to thank all those who provided advice made suggestions.
and to those who said I was wasting my time - yhar-sucks-boo :¬)

Chris

--
_-_- BEAR Labs
- Custom Audio Equipment, Cables, Mods, Repairs -
http://www.bearlabs.com