Open baffle suggestions

[AJ]

Hey guys

I'm looking for some input from some of you that have messed around with way too many bass drivers in a single OB.

I've got sixteen 12 inch Madison Warriors to play with and I'm going to go with 8 per side on an OB with two Audax PR170s for mids and a B&C DE250 in an ENG90 WG for the highs. The baffle is limited to 48 inches wide and I'll go 77 inches high if needed. I can squeak another 4-6 inches of width out of it if it looks like keeping all 8 woofers low to the floor will have a significant advantage. Crossover will be LR4 500/1500hz, active, triamp. These will be in corners on the long wall and angled in toward the center of the room at about 30 degrees.

There's obviously an infinite number of ways to organize the contraption, so I drew up some options to think about. I'm looking for maximum bass extension without adding any boost, but I'm aware that to get a decent 40hz will probably require it.



Where would you start with something like this, given the stated limitations? Any ideas beyond the six shown here?

Thanks.

[adason]

http://www.thevintageknob.org/THEVAU...oundwalls.html

[AJ]

Tnaks for the link Adason. Looks like I need option number 7.

[ttan98]

Hi,

I once asked this question to J.K., he mentioned that Soundeasy s/w has a feature that it can simulate the type of configuration you want.

I have the s/w but not good at using it, possibly you may want to post this query to him.

PS still thinking of buying the Audax midrange, has not pulled the trigger yet. I heard many good reports on it.

cheers.

[Pano]

Just curious - how will adding drivers extend the low end? Other than you'll need a bigger baffle.

All those drivers will move a lot of air, but they'll move it at higher frequencies, too - won't they?

[AJ]

"Just curious - how will adding drivers extend the low end? Other than you'll need a bigger baffle."

I wouldn't think additional drivers would lower it either. I'm just relating to Magnetar's experience with his five 10's per side where he was getting lower output than expected. Why this would be the case, I don't know either. At what levels the lower frequencies end up is another unknown. I suspect room gain will help here.

Also, Mike's woofers have a higher Qts than mine, so I may not get the same results. These drivers have a lower Fs, but that may not make up for their lower Qts. I'm just hopeful, but nothing's gonna be known till they're built.

[pedroskova]

With that many drivers facing the same direction, you'll be shaking that baffle to within an inch of its life. You might want to think about separating / isolating it from your mids and waveguide. I have 8 cheap 12" drivers (4 per side) that I plan on putting in a Linkwitz W baffle. In that configuration, I can keep the dimensions down around 30"H x 18"W x 20" D. You have to deal with the cavity resonance, but the opposing forces cancelling each other makes it worth it.

[AJ]

"With that many drivers facing the same direction, you'll be shaking that baffle to within an inch of its life."

heh heh...yeah that thought ocurred to me too. I was even wondering why I couldn't turn every other driver around, although I haven't really thought that one thru yet.

[Pano]

Originally posted by AJ
I was even wondering why I couldn't turn every other driver around

I've seen it done. Supposed to help keep the baffle from "walking" around, too.

[fergs1]

Greetings , isn't the point of multiple drivers to decrease excursion for a given spl and then you can apply more eq to the bottom end given the limiting factor in ob bass is always xmax and not power
cheers fergs