Modular 2x10 rig with great dispersion?

[kringle77]

Most everyone on here now knows that stacked vertical 2x10 cabs work really well. So what if you need 3 2x10 cabs? Here's an idea. If you low pass the left driver in a cab at 1khz and leave the one on the right full range (up to about 3.5khz) and then let the tweet cover 3.5khz and up, you could then stack 3 2x10 cabs on top of each other. The 3 tweets would be in a perfect columb, the 3 full range drivers on the right would be as well and the 3 low passed drivers on the left shouldn't interfere with the high mid dispersion. It seems like that could be a good modular/scale-able rig. Another benefit would be that more cab is touching the floor and therefore more low end coupling for those who find the vertical stack alittle thinner "sounding".

[kringle77]

Im sure this would work, Im just wondering if 1khz would be a low enough LP?

[will33]

10's side by side would have the dispersion of a 20" cone so you'd want to lower the xover point and probably find an hf horn you could pass at 2500 instead of 3500 in the interest of getting the best dispersion fullrange but yeah, it can work. You'd also want to divide the cabs in half internally so the full range driver isn't interfering with the highpassed one. Also watch spl matching as you'd have more cone putting out mids than lows. Barefaced 610 uses this principle although he uses 3 different drivers, one being a guitar driver for highs instead of a tweet.

[billfitzmaurice]

Originally Posted by kringle77

Im sure this would work, Im just wondering if 1khz would be a low enough LP?

It needs to be no higher than the 1 wavelength center to center distance.

You'd also want to divide the cabs in half internally so the full range driver isn't interfering with the highpassed one.

No need, because no drivers are high-passed. One side of the line is low-passed.

you'd want to lower the xover point and probably find an hf horn you could pass at 2500 instead of 3500 in the interest of getting the best dispersion fullrange

+1. Even with half the line low-passed the full range side of the line will beam above 2kHz.

[kringle77]

yeah, i've taken these things in to account. It just seems like a good way to get the most out of a few common 2x10 cabs. The dispersion would beam at 2khz but still be better than if one driver was not low passed. So there would be a dip between 2k and 3.5k. Still not bad. I don't know how to calculate the center to center bandwidth but figured it must be between 800hz and 1khz. A simple 1st order inductor should work fine.

[will33]

Ya, I guess that is backwards. Having all cones doing lows and half doing mids may sound alright on it's own or could be leveled with a little eq tweak. Better to be heavy in the lows and cut than weak and boost...amp headroom/speaker stress etc.

[Rockin Mike]

What would be a good search to use to find basic starter info on these kinds of things?
"acoustic design principles"? I dunno. Would appreciate some help.

[zombywoof5050]

Too much work, I'd just stack all 3 on end.

[will33]

Originally Posted by Rockin Mike

What would be a good search to use to find basic starter info on these kinds of things?
"acoustic design principles"? I dunno. Would appreciate some help.

This is a good one, there's a bunch out there.

The Speaker Building Bible - Techtalk Speaker Building, Audio, Video, and Electronics Customer Discussion Forum From Parts-Express.com

[Rockin Mike]

Originally Posted by zombywoof5050

Too much work, I'd just stack all 3 on end.

How about joining them with angle brackets and wedges for that "Dr. Seuss" kind of look?

[will33]

Originally Posted by Rockin Mike

How about joining them with angle brackets and wedges for that "Dr. Seuss" kind of look?

Fender tried something along those lines....didn't work out so good.

fender bassman pyramid angled 412 cabinet - Google Search

[billfitzmaurice]

Originally Posted by kringle77

A simple 1st order inductor should work fine.

-1. It would have only a cursory effect.

[kringle77]

Really? What would you suggest Bill? I mean as far as a LP filter? Frequency, order?

[kringle77]

How about a 3rd order at 1khz?

[will33]

I'd think you'd want it down around 250 for best dispersion. 2nd order enough maybe?

[will33]

If coming at this purely with the goal of best dispersion, depending on how the 10's are mounted, you'd have an effective width of a 20-22" cone. Whatever that measurement is 1/4" wavelength of is where it will start to beam so I'd start experimenting at that spot. Rule of thumb is to pass no higher than where it first hits -6db at 45 degrees off axis. You could get away with a bit higher xover point and not notice a difference other than way off to the side. Sometimes a bass "sounds" a little thicker/fuller if you cross slightly higher than optimal, sometimes it doesn't, to me anyway. Depends on a lot of things, it's one of those tradeoff decisions you have to make.

I used to use a biamp bass head to experiment with this type of stuff before it fried. Now I take a pre out from another basshead and run it through a xover and poweramp from the PA. Use something like that to dial it in, then start figuring out a passive for that frequency. The end result will sound slightly different than the experiment as my active crossover is 4th order both ways and a passive will likely be 2nd or maybe 3rd and there's the matter of impedance curves varying with frequency and temperature, etc. but it gets you close.

Good luck.

[kringle77]

Last night I tried this with my 8x8 cab. I'll be damned. 250hz 3rd order worked the best. I wouldn't have thought I needed to go that low but, it sounded the best. It retained the punch of the cab and made it clearer. The dispersion pretty much doubled. With a single cab like this, it really works. With 3 2x10 cabs you may do nearly as well by stacking a pair vertically and the putting the 3rd cab vertically on the floor next to the tall stack. Might be nearly as good and there wouldn't be the hassle of buying/building crossovers.

[billfitzmaurice]

Originally Posted by kringle77

Last night I tried this with my 8x8 cab. I'll be damned. 250hz 3rd order worked the best. I wouldn't have thought I needed to go that low but, it sounded the best. It retained the punch of the cab and made it clearer. The dispersion pretty much doubled.

Makes you wonder why cab manufacturers didn't figure this out 30 years ago. Oh, wait a minute...how much did it cost you to make that filter...20, 30 bucks? Answer found.

[kringle77]

When playing around with crossover points I stumbled on something. Im loving this cab stock but, it does have a bump around 450hz or so that can be alittle annoying. That frequency range seems pretty additive with this cab and I can't eq it out with my amp without effecting the sound too much. I ran the left hand 8's lowpassed 3rd order at 250hz and ran the right side highpassed at 800hz 3rd order creating a mid dip. It sounded pretty good so, tonight Im going to play some more. Im thinking that running 6 of the the drivers at 250 and down and then running the other two highpassed will make the cab even better. I've just got to experiment to see how far down to bring the highpassed drivers. I'd end up using some of the foam rubber cups to create seperate chambers for the high-passed 8's of course. Anybody know where I can find them? I've looked all over under several different names and can't find them.

[billfitzmaurice]

Originally Posted by kringle77

Im thinking that running 6 of the the drivers at 250 and down and then running the other two highpassed will make the cab even better.

I doubt it. If you can't EQ the bump out with your amp use a notch filter on the full ranged drivers, then you don't lose their low frequency contribution.