Small Enclosure Woofer

[h_andree]

I am planning to build a new speaker to replace my
main system. They are wonderful but slightly large:
They are 6'2" and weight about 200 lbs.

I'm planning to build a 4th order sub in the basement.
This would be a 32 cubic feet enclosure with 4 x 12"
woofers. This covers the range 25-60Hz.

The port would go through the floor to the living room.
I would like to make the speakers a 3 way active
system with electronic or digital cross-over (4th order).
I will custom build the amps myself (Based on the LM3875).

I've looked at the tweeter and think I will go with one of the
LCY crossed over to a Fostex FE168 Sigma.

I need a woofer that will work well in a enclosure
of about 1 cubic feet (30 liters) and has a reasonable
sensitivity >89 dB/watt (As the amps will have not much more then
30-40W). The woofer will need to cover 60-250Hz.
Needs to have a very low distortion. I prefer an 8 ohm
driver as the amps really like 8 ohms better then 4.
I think a closed box would be preferred as there's no
phase shift to the port.

What would you use as woofer?

 

[Inductor]

...I'm planning to build a 4th order sub in the basement.
This would be a 32 cubic feet enclosure with 4 x 12"
woofers. This covers the range 25-60Hz.

The port would go through the floor to the living room.

For the 4x8 Ohm subs a 12"XLS
http://www.tymphany.com/categories/peerless/subwoofer
This example with a project of a closed box, "The Critical Q Sub-Woofer".
http://www.customanalogue.com/sub_index.htm

...I've looked at the tweeter and think I will go with one of the
LCY crossed over to a Fostex FE168 Sigma.

I need a woofer that will work well in a enclosure
of about 1 cubic feet (30 liters) and has a reasonable
sensitivity >89 dB/watt (As the amps will have not much more then
30-40W). The woofer will need to cover 60-250Hz.
Needs to have a very low distortion. I prefer an 8 ohm
driver as the amps really like 8 ohms better then 4.
I think a closed box would be preferred as there's no
phase shift to the port.

What would you use as woofer?

One idea that comes to mind is the Fostex FW305.
http://www.fostexinternational.com/docs/speaker_comp/pdf/fw305.pdf

You can also look at other drivers like the SCANSPEAK 18w8535 used for the ProAc2.5 that is a very good driver, with less output at around +-86dB (Fostex is 90/95dB). I tested it here for you in a closed 30L enclosure. (Fostex 12" in a closed/BR enclosure for comparison)

 

[h_andree]

Thanks

For the 2 x 12 I had in mind the Eminence Lab12 Generation II.
I will probably add equalization to tune it to the room.
Advantages of the peerless vs eminence? Actually the
XLS looks impressive.

I do like scan speak. Currently I have dual 18W8555. The bass
is really great. I'm using it with passive radiators in a 2.6
cu feet enclosure with passive radiators.

I guess the higher Q is better. How would
a Morel 8" driver be as the woofer in this setup?
Morel MW-266. Or Eton 8-800 8.

Anybody idea about distortion or whether they would
integrate with the Fostex.

Thanks Harry

 

[h_andree]

Amplifier

I'm also looking for a amplifier to drive the sub. I would prefer
an efficient amp, class T? I do not want a subwoofer amp
since I would like to set my own cross-over points.

The amp will be placed in the basement next to the subwoofer.
I would like to have at leat 250W into 4 ohms.

Anybody any suggestions?

An alternative is that I would make my own using the 4780
chip and adding 1 per woofer (4x). This would cost me
about $700-800 in parts and would add another 100 hours
of work.

Thanks

Harry

 

[Inductor]

h_andree Hi,

Of course the LAB12 is the best in the world. I don't like the material of the surround tough, plain and simple. I like butyl rubber surrounds or paper and don't take this as a code.

<<I guess the higher Q is better. How would
a Morel 8" driver be as the woofer in this setup?
Morel MW-266. Or Eton 8-800 8.>>

I don't know how they would be. But I got another idea for you, based on two speakers (that are very similar). The Black Widows. Peavey 1201-8 12" Woofer 98.5dB(94-100dB) for woofer and 1208-8 SPS BWX 12" 97dB for the 4 subs (Qms=9.513).
Another option is to get this woofer (1201-8) but with a different setup for the sub like two 4Ohm drivers in series.

I can assure you I would choose this baby for a monitor right now (based on the performance of the Impulse 1012 Peavey speaker).

http://www.partsexpress.com/webpage...39&sm=2&so=1&search_type=manufacture&desc=ASC

 

[Inductor]

In reality, for the sub, I would go with a speaker driver with Fs lower than 35Hz of the 15" type specifications, if a had to stay with a 12", I would considerer a auto type to, like the JBL 12"GTO with rubber surround w/two in series and Fs=24.75Hz, price on the 100€/150$ range.