Mega subwoofer picture
 

As promised here is a picture of my subwoofer. I have pushed a settee
out of the way so it can be seen, and also removed a white cloth
screen that normally covers it. So in use it is totally invisible.

http://www.donepearce.plus.com/odds/sub.jpg

The driver is a 15 inch Adire Tempest mounted in an 80 cubic foot
concrete cupboard, which extends under a staircase on the other side
of the wall. The mounting board, which replaces the cupboard door, is
18mm MDF, braced extensively with scaffolding board, screwed and glued
edgewise onto it. It is very solid.

The whole thing tunes pretty nicely with the room to make an almost
flat response down to something very low indeed. At the top end, it
merges and integrates very nicely with the Sonus Fabers, which take
over from about 60Hz.

Last night's Bach was as much a visceral as an auditory experience.

d

Pearce Consulting
http://www.pearce.uk.com

Mega subwoofer picture
 

Don Pearce wrote:
As promised here is a picture of my subwoofer. I have pushed a settee
out of the way so it can be seen, and also removed a white cloth
screen that normally covers it. So in use it is totally invisible.

http://www.donepearce.plus.com/odds/sub.jpg

Very nice - fancy reinforcing the wall and mounting one of these in its
place?

http://www.madisound.com/fw800n.pdf

(project for next house I think...)



--
slightly greasy solar atoms...

Mega subwoofer picture
 

On Sat, 17 Jul 2004 17:04:31 +0100, "Tim S Kemp"
wrote:

Don Pearce wrote:
As promised here is a picture of my subwoofer. I have pushed a settee
out of the way so it can be seen, and also removed a white cloth
screen that normally covers it. So in use it is totally invisible.

http://www.donepearce.plus.com/odds/sub.jpg

Very nice - fancy reinforcing the wall and mounting one of these in its
place?

http://www.madisound.com/fw800n.pdf

(project for next house I think...)

Interesting looking device, but I should think about Xmax before
taking the plunge. That cone is barely able to move. Somehow those TS
parameters don't seem to stack up...

d
Pearce Consulting
http://www.pearce.uk.com

Mega subwoofer picture
 

"Don Pearce" wrote in message
...
As promised here is a picture of my subwoofer. I have pushed a settee
out of the way so it can be seen, and also removed a white cloth
screen that normally covers it. So in use it is totally invisible.

http://www.donepearce.plus.com/odds/sub.jpg

The driver is a 15 inch Adire Tempest mounted in an 80 cubic foot
concrete cupboard, which extends under a staircase on the other side
of the wall. The mounting board, which replaces the cupboard door, is
18mm MDF, braced extensively with scaffolding board, screwed and glued
edgewise onto it. It is very solid.

The whole thing tunes pretty nicely with the room to make an almost
flat response down to something very low indeed. At the top end, it
merges and integrates very nicely with the Sonus Fabers, which take
over from about 60Hz.

Last night's Bach was as much a visceral as an auditory experience.


Not surprised!! :-)

In case you're interested, here's an open mic recording of my Paladins on
the 4 wpc triode amp (excerpt only - Pipex still playing silly buggers with
the webspace quotas):

http://www.apah69.dsl.pipex.com/keit...ganopenmic.mp3

Apologies for the hiss - I don't get that over the system, obviously!

(Actually recorded for some 'before and after' with a possible Black Gate
upgrade to the 2A3 bypass caps and a bit of messing about with the
'scope.....)

I'd be interested in a comparison with your subbed sound - any chance of an
'open mic' from that if you have the same recording??

Mega subwoofer picture
 

Don Pearce wrote:

Interesting looking device, but I should think about Xmax before
taking the plunge. That cone is barely able to move. Somehow those TS
parameters don't seem to stack up...

Indeed Xmax is low, however cone area is significant so the volume of
movement is compensated there.
--
slightly greasy solar atoms...

Mega subwoofer picture
 

On Sat, 17 Jul 2004 17:32:02 +0100, "Keith G"
wrote:


"Don Pearce" wrote in message
.. .
As promised here is a picture of my subwoofer. I have pushed a settee
out of the way so it can be seen, and also removed a white cloth
screen that normally covers it. So in use it is totally invisible.

http://www.donepearce.plus.com/odds/sub.jpg

The driver is a 15 inch Adire Tempest mounted in an 80 cubic foot
concrete cupboard, which extends under a staircase on the other side
of the wall. The mounting board, which replaces the cupboard door, is
18mm MDF, braced extensively with scaffolding board, screwed and glued
edgewise onto it. It is very solid.

The whole thing tunes pretty nicely with the room to make an almost
flat response down to something very low indeed. At the top end, it
merges and integrates very nicely with the Sonus Fabers, which take
over from about 60Hz.

Last night's Bach was as much a visceral as an auditory experience.


Not surprised!! :-)

In case you're interested, here's an open mic recording of my Paladins on
the 4 wpc triode amp (excerpt only - Pipex still playing silly buggers with
the webspace quotas):

http://www.apah69.dsl.pipex.com/keit...ganopenmic.mp3

Apologies for the hiss - I don't get that over the system, obviously!

(Actually recorded for some 'before and after' with a possible Black Gate
upgrade to the 2A3 bypass caps and a bit of messing about with the
'scope.....)

I'd be interested in a comparison with your subbed sound - any chance of an
'open mic' from that if you have the same recording??




Sounds very good, but that final thunder isn't there. Maybe it is the
added room acoustic that is making it just a little "hollow".

I haven't done any open mic of the sub yet - maybe one of these days.
No neighbours around at the mo - maybe a good time!

d
Pearce Consulting
http://www.pearce.uk.com

Mega subwoofer picture
 

Don Pearce wrote:

The driver is a 15 inch Adire Tempest mounted in an 80 cubic foot
concrete cupboard, which extends under a staircase on the other side
of the wall. The mounting board, which replaces the cupboard door, is
18mm MDF, braced extensively with scaffolding board, screwed and glued
edgewise onto it. It is very solid.

The whole thing tunes pretty nicely with the room to make an almost
flat response down to something very low indeed.

Flat? How does that work then?
For a closed box you want about 4 cubic feet for a Tempest.
With a very large box you want some first-order low-boost to equalise
the response.

Mega subwoofer picture
 

On Sat, 17 Jul 2004 18:45:54 +0100, Eiron wrote:

Don Pearce wrote:

The driver is a 15 inch Adire Tempest mounted in an 80 cubic foot
concrete cupboard, which extends under a staircase on the other side
of the wall. The mounting board, which replaces the cupboard door, is
18mm MDF, braced extensively with scaffolding board, screwed and glued
edgewise onto it. It is very solid.

The whole thing tunes pretty nicely with the room to make an almost
flat response down to something very low indeed.

Flat? How does that work then?
For a closed box you want about 4 cubic feet for a Tempest.
With a very large box you want some first-order low-boost to equalise
the response.

Not really - that assumes a very big room. With my room, I was happy
that room gain below about 35Hz would flatten out the slowly drooping
response you get when you just use a big cabinet. It won't be exactly
flat, but it will be a heap better than most subs which artificially
prop up one band of frequencies and forget that there is a room in the
equation as well. My system doesn't actually sound as if it has a sub
at all - simply a well-extended frequency response.

d
Pearce Consulting
http://www.pearce.uk.com

Mega subwoofer picture
 

In message , Eiron
writes
Don Pearce wrote:

The driver is a 15 inch Adire Tempest mounted in an 80 cubic foot
concrete cupboard, which extends under a staircase on the other side
of the wall. The mounting board, which replaces the cupboard door, is
18mm MDF, braced extensively with scaffolding board, screwed and glued
edgewise onto it. It is very solid.
The whole thing tunes pretty nicely with the room to make an almost
flat response down to something very low indeed.

Flat? How does that work then?
For a closed box you want about 4 cubic feet for a Tempest.
With a very large box you want some first-order low-boost to equalise
the response.

Maybe the low-rate roll-off of such a low-Q system matches the rise in
LF output due to room effects quite nicely.
--
Chris Morriss

Mega subwoofer picture
 

Don Pearce wrote:

On Sat, 17 Jul 2004 18:45:54 +0100, Eiron wrote:


Don Pearce wrote:


The driver is a 15 inch Adire Tempest mounted in an 80 cubic foot
concrete cupboard, which extends under a staircase on the other side
of the wall. The mounting board, which replaces the cupboard door, is
18mm MDF, braced extensively with scaffolding board, screwed and glued
edgewise onto it. It is very solid.

The whole thing tunes pretty nicely with the room to make an almost
flat response down to something very low indeed.

Flat? How does that work then?
For a closed box you want about 4 cubic feet for a Tempest.
With a very large box you want some first-order low-boost to equalise
the response.


Not really - that assumes a very big room. With my room, I was happy
that room gain below about 35Hz would flatten out the slowly drooping
response you get when you just use a big cabinet. It won't be exactly
flat, but it will be a heap better than most subs which artificially
prop up one band of frequencies and forget that there is a room in the
equation as well. My system doesn't actually sound as if it has a sub
at all - simply a well-extended frequency response.

Do you have any data to show the effect of opening the doors and
windows on the room gain?
Do you have a sign ooutside:
"Please shut the door to keep the bass in"?