[95Honda]

I have a pair of these 18" subwoofers I had built for some extremely large EBS vented alignmnets I built a few years ago.  They sound good, but I was thinking of trying something new for a while. 

T/S-

Fs- 25Hz
Qes-.64
Qms- 5.09
Qts- .59
Vas- 8.6ft3
Spl- 88db
Xmax- 33mm 1-way linear

I live in Germany now and the local hardware stores have large 4'x9' panels of what appears to be about 1.5" thick particleboard veneered on one side for relitively cheap.

Any thoughts?

[tubamark]

Sounds like a very good potential driver.  For a driver that size, I would start by trying a shallow U-frame, tapered sides.  Perhaps make average depth maybe half of the width.  It will function like a folded baffle rather than than a U-frame/pipe.

The .59 Qts should work excellent, given the low Fs and displacement you have available.

Let us know how it turns out.
-- Mark

[95Honda]

Thanks.

I need to run to the hardware store again and see how many different panel sizes they have, U-shape  may be real easy and get rid of constructing a base for a flat baffle...

[Dmason]

switching amps with larger cones, (large Mms) are the perfect match. High damping factor becomes your best friend with this situation. I recently heard the El Cheapo Goldwood 15 bass cones on OB with a switching based sub amp and they sounded clean, powerful, musical, and the FR is low enough that any switching artifacts are well below the --audible-- bandwidth.

When you low pass bass cones, and use baffle roll as your set-point for mains, ANY driver sounds good on OB, in fact, they sound their best, under unloaded, ie, optimal condiitons.

[scorpion]

X-max couldn't be 66 mm, no way !

/Erling

[FlorianO]

X-max couldn't be 66 mm, no way !

ALL drivers can have 66mm Xmax -- and even more, much more. 
However, that is a one-time-only affair....

 

[95Honda]

Actually, they have a DUMAX verified 33mm one-way linear (10%BL) stroke.  These have the 55lb XBL2 motors Dan Wiggins designed designed for the original Adire Tumult.  I have owned 4 Tumults and several of these 18" XXX subwoofers.  The suspention limits at about 45mm one way (the triple joint/spider smacks into the top plate).  These are very high excursion, low distortion drivers that I though would work great for OB....