In the interest of keeping my neighbour happy by reducing the rumble and
thump that travels though the building from my sub woofer, and sounds like
an earthquake from his prospective.
I was thinking of constructing some sort of isolation platform for the sub,
and I'm looking for some advice on what would be my best solution:
I was possibly considering an air cushion (part inflated innertube) between
a top layer of concrete or granite slab,about 30mm thick, and a lower slab
of thick MDF (36 mm) .
Would a sorbothane or another rubber isolation be better ? could I use a
very thick layer of PVA to make some pucks or use silicon rubber pucks?
The lower slab would need to be isolated from the floor (20mm pine wood
blocks on 150mm solid concrete floor) by some sort of rubber, possibly
focalpods to protect the floor and add further isolation.
the Sub is spiked and would be directly coupled on the top slab.

which would be best ? or am i barking up the wrong tree here?

Thanks in anticipation. Chris.

You can't effectively isolate the rumble to your space as it is
acoustically coupling to the neighbor's pad as well as mechanically.
By eliminating the mechanical coupling, you may reduce it a bit, but
the majority of the rumble is due to the speaker energizing the room
itself if it truly sounds like an earthquake. To mechanically decouple
it, just remove the spikes and set it on a large foam pad (a pillow
will make for a test run). Give it a run with him being aware that you
are going to try something new to help him out and be able to go down
and listen from his perspective at that point as well. If he still
complains, then it's curtains at the Boom theater...
- Bill
www.uptownaudio.com
Roanoke VA
(540) 343-1250

"chris" wrote in message
...
In the interest of keeping my neighbour happy by reducing the
rumble and
thump that travels though the building from my sub woofer, and
sounds like
an earthquake from his prospective.
I was thinking of constructing some sort of isolation platform for
the sub,
and I'm looking for some advice on what would be my best solution:
I was possibly considering an air cushion (part inflated innertube)
between
a top layer of concrete or granite slab,about 30mm thick, and a
lower slab
of thick MDF (36 mm) .
Would a sorbothane or another rubber isolation be better ? could I
use a
very thick layer of PVA to make some pucks or use silicon rubber
pucks?
The lower slab would need to be isolated from the floor (20mm pine
wood
blocks on 150mm solid concrete floor) by some sort of rubber,
possibly
focalpods to protect the floor and add further isolation.
the Sub is spiked and would be directly coupled on the top slab.

which would be best ? or am i barking up the wrong tree here?

Thanks in anticipation. Chris.

I built an isolation stand for my turntable using Aurios MIB 1.0 isolation
bearings. their resonant frequency is 0.5 Hz. for the verticale vibrations I
sandwiched home made silicone pucks with a shore hardness very close to zero
between two plates of acrylic. I don't think much in the way of vibrations gets
through this setup.

"S888Wheel" wrote in message
...
I built an isolation stand for my turntable using Aurios MIB 1.0 isolation
bearings. their resonant frequency is 0.5 Hz. for the verticale vibrations
I
sandwiched home made silicone pucks with a shore hardness very close to
zero
between two plates of acrylic. I don't think much in the way of vibrations
gets
through this setup.

Thanks for the tips.
I've looked at the MIB's they could be what I'm looking for, but what a
price.

How did you do the homemade silicon pucks what silicon did you use ?

Chris

How did you do the homemade silicon pucks what silicon did you use ?
BRBR

I used a silicone from a company called BJB. It is made for prosthetics. It has
a shore hardness of 9 on the D scale. I plasticized it down to near zero with
silicone oil. BJB makes a few silicone elastomers that would work. I just used
what I had.

Hi S888Wheel

Ive been trying that plasticizing trick, with some low modulas silicon
rubber sealant with 1/3 oil.
Wow does it ever cure ? 3 days already.
definatly more complient but I suppose i will have to see how long it take
to fully vulcanise.

Thanks for the tip should make some interesting experiments.



"S888Wheel" wrote in message
news:OQXxb.246018$mZ5.1851674@attbi_s54...


How did you do the homemade silicon pucks what silicon did you use ?
BRBR

I used a silicone from a company called BJB. It is made for prosthetics.
It has
a shore hardness of 9 on the D scale. I plasticized it down to near zero
with
silicone oil. BJB makes a few silicone elastomers that would work. I just
used
what I had.

A quick update just in case "anyone" is interested
5- 6 days after the mixing this stuff was cured.
its quite a bit softer (squiggier) I would guess by feel about 50% reduction
in stiffness than the untreated silicon but still has a good spring back and
about 20% slower return. So it should be quite good for absorbing vibrations
under a heavy load.

Chris.

"chris" wrote in message
...
Hi S888Wheel

Ive been trying that plasticizing trick, with some low modulas silicon
rubber sealant with 1/3 oil.
Wow does it ever cure ? 3 days already.
definatly more complient but I suppose i will have to see how long it take
to fully vulcanise.

Thanks for the tip should make some interesting experiments.

Next time add a drop of water. It will cure about five times faster.

(S888Wheel) wrote in message ...
Next time add a drop of water. It will cure about five times faster.

Let me see if I got this recipe straight: 2 parts low modulus silicon
rubber sealant (...you mean like tub caulk?), 1 part oil (salad oil?
motor oil? heating oil?), & 1 drop of water = a DIY Sorbothane
equivalent? Tell us more!

Let me see if I got this recipe straight: 2 parts low modulus silicon
rubber sealant (...you mean like tub caulk?), 1 part oil (salad oil?
motor oil? heating oil?), & 1 drop of water = a DIY Sorbothane
equivalent? Tell us more!

No. You haven't got it right. We are talking about two component tin based
silicone elastomers with very low shore hardness plasticized with silicone oil.
The water speeds up the cure. It isn't a necessary ingredient. The right
formula will out perform sorbothane.

Well actually, im using the gun caulk stuff with silicon oil, its probably
why it takes so long to cure in the moulds.
but its fun :¬)
Merry Xmas all

Chris.

"S888Wheel" wrote in message
...

Let me see if I got this recipe straight: 2 parts low modulus silicon
rubber sealant (...you mean like tub caulk?), 1 part oil (salad oil?
motor oil? heating oil?), & 1 drop of water = a DIY Sorbothane
equivalent? Tell us more!

No. You haven't got it right. We are talking about two component tin based
silicone elastomers with very low shore hardness plasticized with silicone
oil.
The water speeds up the cure. It isn't a necessary ingredient. The right
formula will out perform sorbothane.

=20
Well actually, im using the gun caulk stuff with silicon oil, its probabl=
y
why it takes so long to cure in the moulds.
but its fun :=AC)
Merry Xmas all

That explains a lot. I don't think you will ever beat sorbothane with tha=
t.