SUBWOOFER DESIGN

Archived from groups: rec.audio.tech (More info?)

Hi

I am trying to build an 8" subwoofer using a driver unit from "Dainty
Speakers",Taiwan.The specifications written on it says that it can
handle 200W RMS.There are no other datasheets or any Thiel-Small
parameters accompanying the drive unit.Now that makes my effort of
making a suitable enclosure more difficult.I am looking to bulid some
sort of bandpass enclosure for use with my home theater system.I have
designed my subwoofer active filter with a frequency bandwidth of 30Hz
to 105Hz.I dont expect the 8" driver to handle frequencies below
.....say 25Hz.

Now,can somebody help me with making a suitable bandpass enclosure for
this particular drive unit.I am planning to use LM3886 as the
amplifier for this purpose.

Thanks in advance

Suraj

Archived from groups: rec.audio.tech (More info?)

"Suraj" <suraj@stendekrnd.com> wrote in message
news:372297e2.0408151037.1ecd8c44@posting.google.com
> Hi
>
> I am trying to build an 8" subwoofer using a driver unit from "Dainty
> Speakers",Taiwan.The specifications written on it says that it can
> handle 200W RMS.There are no other datasheets or any Thiel-Small
> parameters accompanying the drive unit.Now that makes my effort of
> making a suitable enclosure more difficult.I am looking to bulid some
> sort of bandpass enclosure for use with my home theater system.I have
> designed my subwoofer active filter with a frequency bandwidth of 30Hz
> to 105Hz.I dont expect the 8" driver to handle frequencies below
> ....say 25Hz.
>
> Now,can somebody help me with making a suitable bandpass enclosure for
> this particular drive unit.I am planning to use LM3886 as the
> amplifier for this purpose.

Here's some articles about measuring T/S paramters for yourself:

http://www.diyaudio.com/forums/showthread/t-27663.html

http://ldsg.snippets.org/HORNS/measure.html

http://www.purebits.com/appnote16.html

http://www.partsexpress.com/pe/psh [...] -034&DID=7

I would not attempt a bandpass design without T/S parameters that I believed
in, and a good low-velocity vent.

Archived from groups: rec.audio.tech (More info?)

"Sugarite" wrote
> "Suraj" <suraj@stendekrnd.com> wrote

[...]
> > Now,can somebody help me with making a suitable bandpass enclosure
> > for this particular drive unit.I am planning to use LM3886 as the
> > amplifier for this purpose.
> It's just a box.
> Stuff it dense and modes won't bother you.

No, I woudn't do that.
What _bass_ modes are there in about 2' by 2' by 3'?

> Don't make it more complictated that it has to be.

Yeah, life can be easy, and sometimes even more
than _you_ think...;-)

Rudi Fischer
--
....and may good music always be with you