BIG OB's

[weikertball]

Has anybody made open baffle tower speakers in a MMTMM arrangement? Since the Goldwood 18" woofers went on sale at Partsexpress, I thought it would be a good idea to start on a new build. Instead of a tweeter, however, I want to use a 8" ful range OB also. Just want some opinions on how this would work and if anyody has

here's an example:

[Scottmoose]

It's not unknown. Not quite an FR driver, but someone did something similar using Hawthorne Silver Iris coax units & 4 of the helper 15in woofers per channel.

Depends on your XO point -you'll want to keep it fairly low so the polar response remains reasonable, although you're approaching a quasi bass-array with what you're looking at. YMMV of course.

[planet10]

On soome thread here one of the Australian members is doing an WWMTMWW with the Vifa P13.

dave

[weikertball]

Cool. That's something I was looking for. The crossovers will be active so I can play with XO points but at first I thought having the Goldwood's play bass and lower mid and the the fullrange go from there.

[badman]

Assuming the 18"s are getting crossed in very low, they should be fine. I'd be more inclined to do a WMTMW with a small fullrange (fostex ff85k) brought in to be a midtweet (500Hz XO or so, 2nd order to maximize power handling and keep midwoofs out of severe breakup) and 2 decent midwoofs like the 15"s here NHT Clearance, run with no high-pass filter, and the 18"s rolled in below them, using a line-level filter and separate amps.

[Godzilla]

The 18" woofers loose much of their efficiency on OB... (around 10db as i understand it) ... does the same hold true for a full range driver like a Fostex 207 or 167?

[REC1]

Next OB. Using Martins XO. Alpha 15 and Fe87.

ron

[Scottmoose]

Clever. Ever get the feeling the lads working on Sound Mirrors (one of my major inspirations) back in the 1930s at Denge knew what they were about?

[REC1]

I figure why fight it? Just treat the OB as a divider or one of those folding Japanese things and be done with it.
Using a hindge at the panel ends and the whole thing can be kinda,sorta tuned.
A center section around 36" width could be added providing a mounting for the flat screen or whatever as well as a mounting panel for audio components and such.
I ran some rough sims for the rear wave and the angled wall interface allows for a much closer ,to the wall, position.

So it comes down to 1-36x48 and 2-48x48 ply or whatever panels,mount the hindges and cut the holes and tune away(give the tweaking addicts something to do).
So simple even i can do it.

ron

(added note! if you have to move ,uggggg!, just remove the drivers and fold it up. makes for a more mobile society)

(the hardest thing you can do is to make it simple)

[sreten]

Originally posted by REC1

Next OB. Using Martins XO. Alpha 15 and Fe87.
ron

Hi, I do not think MJK's XO will work well with radically different baffles, /sreten.