Budget Subwoofer Project

[benb]

If the crossover frequency was mentioned in this thread, I missed it. I see where the specs say this driver goes to 3000Hz, but as a subwoofer I would think it should be rolled off above 60 to 100Hz, which should keep it from activating any resonances or at least reducing their level.

[nazaroo]

Originally Posted by benb

If the crossover frequency was mentioned in this thread, I missed it. I see where the specs say this driver goes to 3000Hz, but as a subwoofer I would think it should be rolled off above 60 to 100Hz, which should keep it from activating any resonances or at least reducing their level.

Yes this is quite right:
My plan is to use it to finish the bottom end of my near-fields,
which are a Focal midrange and Focal tweeter (stereo).

I was thinking of crossing over around 120 Hz,
but I could see going as high as 200 Hz.
Still, the box should be safe from most resonance problems,
with most of the power going to the mid.

If this works, I'll look for another suitable end-table at Ikea,
and make a matching pair (left and right).

Its a fun idea to think of trying it out for a bass guitar,
but I really can't see pumping it with more than 50-70 watts,
and that might be pushing it too far.
Even then, I think I'd choose to add a high-power tweeter,
and a crossover, maybe down as low as 1k anyway.
So there will still be few serious resonances,
and hopefully none at all on the bass fretboard range.

As for playing bass through this,
It has to be better than the rinky-dink speaker that came in the Rumble 60.
I may just hook it up to that amp to see how different the sound is.

12" underpowered "Fender Special" speaker, small magnet (prob.50w)

Bass Reflex Cabinet w. slot along bottom:

9" deep X 15 3/8" wide x 15 1/4" high (16 3/4" at back) interior box,

= 2140 cubic inches (1.24 ft³, .035 m³ )

with port/slot = 3/4" high x 16" wide, (12 Sq. In.)
and about 7" deep. (84 cubic in. in volume).



As it is, the cabinet has a horrible "honk/peak" with the low E string,
and another one about an octave higher. Very uneven bass response,
the four-knob EQ doesn't fix this,- not even in the ballpark.

Already here I will have doubled the cubic feet at 2.5 ft3,
and the Pro speaker must be 4 times the watts of the Fender.



The only issue is the soft rubber surround vs. the reinforced cloth accordion surround of the Fender.
There will probably be less midrange presence.

I could also try porting the cabinet.
Any ideas on that?

[nazaroo]

Originally Posted by revboden

Stiffness isn't everything.

"...That's what she said..."

How does it sound?
Have you tried playing your bass through it?

Chris

Just finished Test 1:

As subwoofer with Focals:


FABULOUS!

List of cuts:

Emma Shaplin Carmine Meo - Bass is all there, completes the background vocals properly.

My Love is a Mountainside - Diana Krall - The Bass is two feet away, and I can feel his fingers. The Hall reverb is breathtaking: Close your eyes and imagine the large expanse being filled with Diana's sweet voice. I was missing the bass element in reverb, and had forgotten how its supposed to be!

Batonga - Angelique Kidjo Powerful clean bass - The Xylophone jumps out and vibrates! Kick drum is in the room.

Chicago Transit Authority - I'm a Man - drums jump out now, organ is sweet. Kick drum is two feet away. Guitar sounds authoritative. vocals sound better.
each drum in the solo now has a personality.

Peter Gabriel - Father - organ/synth carries the whole room along the river. Bass is dramatic, individual tracks are clear.

Santana - Singing Birds, Crying Beasts. - the rolling cymbal work has depth and expansion. The piano is clear and musical. Santana's guitar sounds the same. The percussion is delicate and delightful.

Deborah Cox - Be Good to Me - The synthesized Bass is Jaw-dropping and clear with full effects.

etc. etc.

I'm going to hunt down this piece of furniture and buy 3 more,
and turn them into sub-cabinets!!

Holy moly...the materials are awesome, (and apparently my design was more than adequate.)

The rebuilt speaker seems to be holding up fine for this function anyway...

[mr. doom]

Looks like some of my experiments.

I would not waste any time on a car/home speaker for musical instruments cabinets. Most bass guitar speakers have a bit of "character" and can handle more abuse with the accordion surround.

MCM has some dirt cheap 12"s that would be better.

[nazaroo]

Originally Posted by mr. doom

Looks like some of my experiments.

I would not waste any time on a car/home speaker for musical instruments cabinets. Most bass guitar speakers have a bit of "character" and can handle more abuse with the accordion surround.

MCM has some dirt cheap 12"s that would be better.

Yes, I noted the MCMs in my Marshall Cabinet thread.

The point here was, basically:

(1) I got the furniture free, pre-finished, and only needing a back and front, and some reinforcing.

(2) I got the bass sub-woofers free, abandoned in the garage by a previous tenant.

(3) The purpose for this cab is as a sub-woofer for my stereo.


The success of the project is in part as a result of cost.
Others may find suitable furniture free or unused,
and may be encouraged to make a cabinet from it.

My total cost was:

(1) Some 1/2" plywood scrap I had laying around.

(2) a few hours of sawing, gluing and screwing.

(3) a few dollars for screws and glue.


I think its a go.