Huge Concrete speaker cabinets in foundation

[Graydon]

Hi Guys,

I need some help here. I've built lots of guitar amps and speaker cabinets but only a very few home audio speakers. I have never had the opportunity to do something like this but seeing as we are adding an addition to our house, I now have an opportunity to build some gigantic speakers right into the foundation of the studio downstairs. In this photo you can see the foundation walls which form two speaker cabinets. I now have the forms made for the top which will be 6" concrete also. Just outboard are two narrow "closets" which can be used as part of the speaker system if need be. I imagine I could pop a hole in the outer wall of each cabinet near the back and use the outer narrow closets to house the mouth of a large folded horn. I have been considering using an active crossover and triamping the system. The space between the two cabients will be used to house amps/crossovers, etc and probably a large screen TV before too long.

What goes into the large cabinets is up in the air. I can do anything that fits in this enclosure. My tentative plan is to mount a pair of 18s on each baffle which will attach to the front of the cabinet with angle iron frames which will be anchored to the concrete. What I use for mids and tweeters is completely open at this point. I'm looking for suggestions regarding the best drivers to use, how many, what kind of crossover to use, etc.

The room will be 16' x 24' with a 7.5' ceiling. I will be free to treat the room in any way I need to make it sound good.

Any ideas? Am I crazy?

[Centauri]

I knew I had seen something like this, and found the link - have a look at this. May give a few ideas.

http://www.royaldevice.com/custom.htm

Cheers
Graeme

[Bill Fitzpatrick]

You're not crazy but you're inconsiderate for posting a 600K photo.

[Graydon]

Thanks, yes, I've seen that. I would like to have gone to that extent but I decided that it was just more time and money than I have currently.

Sorry about the 600k photo. It only takes 15 seconds to DL on my machine so I guess I forget some don't have fast connections.

OK, it is fixed now... only 180k.

[Centauri]

Even halving the length of that horn and using Eminence lab12 (one each horn) would blow almost anything else away..........

[Centauri]

Here's another interesting under floor design...

http://www.diy-systems.com/en-us/pg_18.html

Cheers

[BassAwdyO]

Im not sure I understand the purpose of building the concrete closets. It looks to me like there is quite a bit of wasted space near the sidewalls and inbetween the closets. Can you draw a sketch of where the speakers are going?

[Graydon]

In the middle is an open space for equipment. The speaker cabinets are on each side of that and are 40" wide by 44" deep. They are going to be 7.5' high. Then on the very outboard ends are two narrow cavities which can be used for folded horns if I decide that is useful. Otherwise I'll build a couple pull-out media closets to fill those cavities.

I'll see if I can upload a sketch of the tentative plan later.

[Brett]

Originally posted by Graydon
In the middle is an open space for equipment. The speaker cabinets are on each side of that and are 40" wide by 44" deep. They are going to be 7.5' high. Then on the very outboard ends are two narrow cavities which can be used for folded horns if I decide that is useful. Otherwise I'll build a couple pull-out media closets to fill those cavities.

I'll see if I can upload a sketch of the tentative plan later.

Make the cabinet holes a fraction deeper and you can load in a pair of LABhorns per side as well as some long J shaped midbass horns and HF horns. Yum.

[MrGuitardeath]

Originally posted by Centauri
Here's another interesting under floor design...

http://www.diy-systems.com/en-us/pg_18.html

Cheers

Settle down, nobodies calling you an under floor design