Secondly cabinet isolation..... you don't want your sub box hovering an inch off the floor through vibrations before it makes a quick (seemingly intelligent!) dash for the door and onwards to freedom when you're not looking (enjoying the bassy bit).

So how to kill two birds with one stone.. or more if you wanted to use one box for a multitude of applications...

create a fairly normal box to house the speakers in, with a little bracing, but nothing major, put that on some rubber feet, and build another box around it, but with a gap between the walls of your new box and the walls of the old box. with rubber feet mounted in strategic locations to keep a constant spacing between the inner and outer box.

The outer box could be made a generic size if you wanted, allowing you to fit different internal speaker kits inside it....

So problems....

Ports.... the port would need a flexible section inbetween the inner and outer section, sealed at both ends to the relevant piece of wood. In effect like a bellow.

Speaker. The speaker would be mounted on en extension from the inner box, in effect a spacing ring, that would bring it out from the inner box to the surface of the outer box. there would then be a flexible rubber gasket connecting the outer box to the speaker for an airtight, but flexible seal. It wouldn't allow vibration out from inside, but would allow for movement of the internal box.

For the Higher frequency part of the setup I prefer something along the lines of the B&W Nautilus idea of a sphere leading into a tapered tube... not hard to build for those of us with fibreglass experience..... www.bwspeakers.com

So what do you all think Does it have the oooh! factor? Building it wouldn't be a challenge. Or am I just wasting my time here?.... mind you when you see people milling sub boxes out of aluminium billet you know something is wrong.

Colin

Method of attaching outer box to inner box.

You obviously pick nodal points for minimization of vibration transfer and you're basically using air as the insulation medium between non-node panels.. So, why not take it one step further, seal the gaskets well and make a vacuum or low pressure region to damp even more?

Your gasket around the driver will recieve a decent bit of sound energy.. Should it be very flexible?

Also, if you're using a port, you're getting port reflections and inner box turbulence commuted to the listening space that are on the same order of magnitude as well braced cabinet flexion Why go to such trouble to damp a vented enclosure?

I thought about the vacumn idea, but it brings in too many other problems.

As far as nodal points, attaching it where the bracing is attached should help, it would be a good idea.