My Furniture Subwoofer

[Audioholic]

<font color='#000000'>Well one day I was thinking how to put an 18inch sub in the living room without having a problem with my mum. So a thought came to my mind watching that piece of furniture sitting in the corner with nothing in it. My occupation is an audio engineer and had lying around from a night club that didn’t go that well one B&C 18inch loudspeaker. I measured the bottom face of the furniture and the 18inch fitted perfectly. I have it powered by a Caudio 3001 professional amp rated at 2x650(4ohms) driven by the sub pre out of my Yamaha DSP-A2, and guys I can say one thing, IT REALLY ROCKS….

photo 1 :
http://briefcase.pathfinder.gr/downloa....ub1.jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209302/0/sub1.jpg)

photo2 :
http://briefcase.pathfinder.gr/downloa....ub2.jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209303/0/sub2.jpg)

photo 3 :
http://briefcase.pathfinder.gr/downloa....ub3.jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209304/0/sub3.jpg)

photo 3.1 :
http://briefcase.pathfinder.gr/downloa....3.1.jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209318/0/sub+03.1.jpg)

photo4 :
http://briefcase.pathfinder.gr/downloa....ub4.jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209305/0/sub4.jpg)

photo 5 :
http://briefcase.pathfinder.gr/downloa....b5..jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209306/0/sub5..jpg)

photo 6 :
http://briefcase.pathfinder.gr/downloa....b6..jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209307/0/sub6..jpg)

photo 7 :
http://briefcase.pathfinder.gr/downloa....b7..jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209308/0/sub7..jpg)

photo 8 :
http://briefcase.pathfinder.gr/downloa....b8..jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209309/0/sub8..jpg)

photo 9 :
http://briefcase.pathfinder.gr/downloa....b9..jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209310/0/sub9..jpg)

photo 10 :
http://briefcase.pathfinder.gr/downloa....10..jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209311/0/sub10..jpg)

photo 11 :
http://briefcase.pathfinder.gr/downloa....11..jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209312/0/sub11..jpg)

photo 12 :
http://briefcase.pathfinder.gr/downloa....12..jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209313/0/sub12..jpg)

photo 13 :
http://briefcase.pathfinder.gr/downloa....13..jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209314/0/sub13..jpg)

photo 14 :
http://briefcase.pathfinder.gr/downloa....14..jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209315/0/sub14..jpg)

photo 15 :
http://briefcase.pathfinder.gr/downloa....15..jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209316/0/sub15..jpg)

photo 16 :
http://briefcase.pathfinder.gr/downloa....16..jpg (http://briefcase.pathfinder.gr/download/stevegr/18061/209317/0/sub16..jpg)</font>

[Rip Van Woofer]

<font color='#000000'>Your links aren't working. But based on your description I have two questions:

1) Do your drinks tend to vibrate off the edge of the table?

2) Have you checked the house for structural damage?</font>

[Audioholic]

<font color='#000000'>Well your right the links aren’t working, I’ll try and find out what the problem is…thanks..


OK, its fixed, check it out..</font>

[Rip Van Woofer]

<font color='#000000'>Whoa! I'm surprised it doesn't go dancing around the room!

With the base of the table right against the floor all the way 'round, and no visible grills or ports for rear (of driver) radiation, where does the sound come from?

I would have braced it more internally given the quality of most mass-produced furniture but if it works, it works! Just wondering a teeny bit if the table might eventually self-destruct!

DIY is fun. Enjoy!</font>

[Audioholic]

<font color='#000000'>Well when it’s very loud sometimes it does got bouncing around and I say sometimes because the hole thing is EXTREMLY heavy, the driver on its own weighs 13kg + another 40kg of the furniture that’s about 53KG, but because of the very VERY high power that this speaker can handle (almost 1000Wrms) it is logical that sometimes it goes for a walk.

Now probably you didn’t notice I have to port’s installed on the back tuned at 45hz, but I still have a problem with the base. There is a small gape between the floor and the furniture’s base so that at very high volumes causes some small whispering sounds that cant be heard easily. So I’m working on a new base system, which will have a more open-air gap underneath.

Rip Van Woofer you wrote: “With the base of the table right against the floor all the way 'round, and no visible grills or ports for rear (of driver) radiation, where does the sound come from?”

As you might know the low frequencies aren’t directional so you can feel them even if the speaker isn’t facing you, especially with frequencies from 100hz and down…

This is what was written about the driver I used: &nbsp;

The most powerful 18" in our product range, 2000 W continuous program power handling, defines the "state of the art" about LF reproduction. A four inch copper wire voice coil with very high thermal capability and a ventilated magnet assembly allows a low power compression. A very low distortion figure is obtained using a double spider design and dual demodulation rings in the magnetic path. Proprietary water-proof cone treatment for safe use in adverse climatic conditions.

Link: &nbsp;http://www.thielesmall.com/database.asp#

<img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'> &nbsp;<img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'></font>

[Rip Van Woofer]

<font color='#000000'>Nope, didn't see the ports (didn't look at every pic). Yep, know about bass freq. omnidirectionality and of course there are lots of down-firing subs out there.

Make cutouts in the base and your "whispering" problems are over. Add those rubber furniture feet, too.

If you're even inclined to get back into the innards consider some cross bracing. I'll bet the table "sings along" a bit now. Bracing might make it sound cleaner (even if it sounds good now).

Makes me wish I had a table like that to play with!

What does your mom think about all this? Has it re-awakened the boogie fever in her?

I have to tell you, this just gives me the grins. Maybe because I'll bet I'd do the same thing if I had a nice big driver like that just sitting around and happened to see a possible cabinet candidate just begging to be converted. I could imagine that little demon whispering in my ear, "Go ahead!! DO IT!! You KNOW you WANT to!! The h*** with Thiele/Small parameters! Just stick that sucker in there!!"</font>

[Audioholic]

<font color='#000000'>Well I thought of cross bracing the in side but because the wood is very thick, if I remember well 2.5cm, so I thought that it wouldn’t need it and after I finished it and heard it, it didn’t..

At the start I didn’t tell my mum, I just took it down to the basement and started.. when she saw what I did she said ’are you crazy?’. I told her would you prefer I had a big box in the living room? So she didn’t have any problem..
Well I love making things with my hands and especially making speakers.





<img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'></font>

[zumbo]

<font color='#000000'>This is way cool! <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/laugh.gif" border="0" valign="absmiddle" alt=':laugh:'> I bet you won't be sitting that lamp back on that jewel! &nbsp;<img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/down.gif" border="0" valign="absmiddle" alt=':down:'></font>

[Audioholic]

<font color='#000000'>yeah, thanks.. <img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=':;):'></font>

[ThA tRiXtA]

<font color='#000000'>you are crazy &nbsp;<img src="http://www.audioholics.com/iB_html/non-cgi/emoticons/mad.gif" border="0" valign="absmiddle" alt=':angry:'></font>

[CyboLynx]

<font color='#000000'>add some woden spikes to the bottom of the table ...the sub speaker spikes ....

nice work .... iv got 2 tables to play with ... iv also thought about making a sub box outta them ....

im thinking about 2 15" one in each box ....how much did it cost you in materials ?

not including the sub ....</font>