"BEAR" wrote in message
news:LOiOb.88245$xy6.159691@attbi_s02...

This just a sandwich of innertubes and MDF?

Yep plus Sorbothane feet below the 2 layes of MDF bit more MFD and
rubber and innertubes and another layer of MFD allthough i should add
the MDF was treated with "noise killer" i dont know how much this
effected the whole sandwich ? just did it,- just in case.

Impressive result. Extremely impressive result.
I too was VERY supprised, my orignal thoughts were "here goes, not a
lot"-hope it works a bit, I never thought it would be "that" good, the
neighbour was also happy.

You're sure of what you measured?
yes a total attentuation of 60db from one flat to another.
my conversations with the neighbour in his flat was registering
between 54 and +66 db so i know the meter was working on its 60db
setting.
After measuring downstairs I went back upstairs to double check the
volume it was still at 110db.

the *air* transmitted component being a scant 50dB remaining?
Im not totaly sure what you mean by this ? but I will make a guess:-
As I have no absolute referance points I can't say how much of the
propergated sound was via the air. I guess it would be a bit difficult
to find out? But its got to in that ball park somewhere, i dont think
the platform gives 100% insulation.

All i have to do now is figure a way of keeping the sub from falling
off a not very stable platform. oh well, there has to be a
soultion -somewhere.

But as a happy neighbour was the project's primary objective, and I
dont really want to run another set of experiments which serve no
purpose to him, except annoyance.

I dont intend to run (normally) with an spl over about 95-ish db
anyway.
otherwise it looks like could be destined to become a totaly deaf
b'stard .

I just really posted the results to let everyone know what is
possible, especially for the other apartment dwellers out there, to be
able copy /replicate, keeping other neighbours happy.

Just wish the bloke above me would do the same .