Driver at floor level or ceiling??

[Moondog55]

In a short time we are building an extension to the house, moderately sized ( 5600 * 6600 ) and will be our main living and listening area.
There is a small possibility I may be allowed to build in a pair of subwoofers.
the only allowable possibility would be in the two opposite corners of the room and limited to a maximum of "about" 450/550mm width on the diagonal. Assuming I get permission to buy a pair of new 15 inch sub drivers
( otherwise I need to use multiple cheap 12 inch woofers with an Fs of ~30hz ) where would you optimally mount the drivers, floor, ceiling or mid point??
Ceiling is 2700mm in that corner and the planned built-in shelving will be ~330mm deep.
If building in we can add the framing to the plans now, there being a 6 month lead time on the build at the moment tho

[tb46]

Hi Moondog55,

I highly recommend this thread: http://www.diyaudio.com/forums/subwo...-approach.html (start with the link in Post #5).

Regards,

[Moondog55]

I am familiar with that paper and I'll use that approach for the HT
I was more interested in the fixed subwoofers idea for music.
At the moment I have 7 small plate-amped subs and a couple of bigger passive units

[m R g S r]

Build a fake wall without her knowing
Really thou, why not a simple tapped pipe, built into the false wall, would only take maybe a foot of depth off the overall size of the room, and you could make the path length as long (tall or wide) as you want to get that desired 15-20hz!

[DrDyna]

Originally Posted by m R g S r

Build a fake wall without her knowing
Really thou, why not a simple tapped pipe, built into the false wall, would only take maybe a foot of depth off the overall size of the room, and you could make the path length as long (tall or wide) as you want to get that desired 15-20hz!

Yeah, you could probably fit a pair of LMS Ultra 5400 tqwt cabinets behind a false wall and only have the mouth peek through a hole that looked like an hvac air duct

I flirted with this idea myself.

[gafhenderson]

i was under the impression that placing a bass speaker high up in the air would reduce its low end output by doing something to its room gain?

[DrDyna]

Originally Posted by gafhenderson

i was under the impression that placing a bass speaker high up in the air would reduce its low end output by doing something to its room gain?

I'd say from a purely geometrical perspective, the middle (height wise) would be the point in which that factor was the most pronounced and then reduced as you went higher to the ceiling as the ceiling would take the place of the floor as a boundary.

I've nothing to prove this though, perhaps someone has done this or has more insight.

[Moondog55]

I guess there is the room mode to be considered as well.
Corner placement could possibly have an adverse effect.
that will be modified by 'A"the opening into the other room ( big kitchen /dining area ) tho, and "B" the fact that at this stage we look like going with a scissor trussed roof to give the maximum number of angles and "C" the fact that the woofers will be at an angle to those corners.

I did think bout the room gain corner loading which is one of the reasons for asking the initial question.

Building in is simply the cheapest option to maximise WAF, I mean 8 * 12 inch woofers ( 4 per side ) would be adequate don't you think??

[picowallspeaker]

I mean 8 * 12 inch woofers ( 4 per side ) would be adequate don't you think??

I wonder what would happen if playing a vinyl record and the caption/turntable system is a little 'resonant' .
The classic 'rumble' filter would not be adequate

[Moondog55]

Originally Posted by picowallspeaker

I wonder what would happen if playing a vinyl record and the caption/turntable system is a little 'resonant' .
The classic 'rumble' filter would not be adequate

Well that does happen at the moment, it needs +12db on the bass and the loudness button active at the same time tho

I'll work on the turntable isolation a little more- or save "LOUD" for the digital media.
Seriously tho I do have a large number of those woofers meant for an IB installation and them we moved house