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:
here's an example:
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.
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.
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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.
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.
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?
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)
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)
REC1 said:
Hi, I do not think MJK's XO will work well with radically different baffles, 🙂/sreten.
Hi, I do not think MJK's XO will work well with radically different baffles, /sreten.
Sure it will, just goes lower in frequency due to the increase in baffle size and with the Alpha mounted the same (low) will not cause any floor bounce. There is little , if any, U or H frame action so the efficence will be the same. However i simmed a tiny bit of horn action on the rear due to the slight expansion. This can be countered by moving the drivers to near the outside edge.
Roll off (LF), i believe, will be the same. Add some roll foam (pipe insulation) to the top edge and edge diffraction becomes a lesser issue.
ron
Sure it will, just goes lower in frequency due to the increase in baffle size and with the Alpha mounted the same (low) will not cause any floor bounce. There is little , if any, U or H frame action so the efficence will be the same. However i simmed a tiny bit of horn action on the rear due to the slight expansion. This can be countered by moving the drivers to near the outside edge.
Roll off (LF), i believe, will be the same. Add some roll foam (pipe insulation) to the top edge and edge diffraction becomes a lesser issue.
ron
Sorry REC1 I did a quick sim of it and I agree with Sretan - the crossover won't work. The larger baffle will bump up the response in the midbass as well. You might be able to get away with it if you start playing with the placement of the woofer on the baffle (raise it up?). Your baffle is radically different, as noted, and a larger baffle doesn't just extend the bass.
Nothing is going to replace getting some different values of
passive components and playing with it until you are happy. To
get to that you can simply start with Martin's XO values and take
it from there.
😎
passive components and playing with it until you are happy. To
get to that you can simply start with Martin's XO values and take
it from there.
😎
Hey, I think I recognize those big open baffle speakers! They are no longer in use, but they did work very well. I tri-amped the speakers and would bi-amp at the minimum if trying to do this. There are smaller, high quality open baffle woofers you could use to scale the baffle down too, depending on design goals. I can confirm that a pair of towers with 10-15" drivers *could* dominate a room visually. Dynamics and scale seemed to be uncompromised though! Have fun......
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