Questions about Line Arrays

[Kensai]

Alright, I've got 10 planar drivers that are about 4" wide by 7" tall. We can call it about 8" each for minimum mounting space for each, so I can get a line about 40" tall on each side to make an array.

So, first question is, will a line this short actually function as a line array? If not, since these drivers have very long areas that are producing the higher frequencies, can I space them out a bit more.

Okay, assuming there's a way to do this with these drivers, the second bit is about getting my bass. The planars are good down to about 200Hz, at which point they absolutely fall off a cliff (they can actually be run full range with no distortion or other issues due to the sub 200Hz signals, so that will simplify my crossover work). I'll be mounting them in open baffles, and I want my bass to be OB as well. Can I run just a single woofer at the bottom of the array to cover the sub 200Hz area, or will that cause some issue I am not aware of (notice, when it comes to arrays, I am not aware of much, yet)?

An assuming that part is okay, too, any suggestions on drivers for this configuration? I'd like to keep the baffle as narrow as possible. Its going to be hing mounted to the side of a 7' tall oak entertainment center and have about 2' clearance to the wall behind and 2'-3' clearance to the side walls. I had been thinking about one of the Tang Band 8" or oval shaped sub drivers (for some reason I'm thinking that an extended range woofer, like most 8"ers will go up to 2khz-5khz, wouldn't be ideal for this application, though I could easily be wrong), but their Qts values are way too low, and would probably stay that way even with a large inductor on them for a lowpass. Probably the best driver I've seen for the app would be the 15" Dayton IB driver, but its quite pricey for this situation and would require me to make either way too wide baffles or some oddly shaped tappered baffles.

So, what do you think? Any answers? Any comments? Any reason to just shelve this idea immediately because it won't work?

Kensai

[RJ]

It sounds like you got the B&G 8 planar's. I don't think they can really go as low as 200 hz like it shows on their graph. I've read where many DIY'ers like to cross around 1 khz. I got 4 that I was going to pair up with 8" RS drivers, but that's as far as I got.
My line-arrays with the Dayton Planars.

[Kensai]

RJ,

Actually, they're Monsoon drivers from the last line of PC speakers they made before going out of business. The membranes on them are really quite large, and they do go down to 200hz. I actually had 4 of them rigged into a 2x2 panel on a 16"x20" baffle once and with alot of power and a good bit of EQ, I had them down to 150.

I've actually got a pair of BG Neo3PDRs running with a nice smooth 8" woofer as the mains in my living room. I've had a pair of these Monsoons running the same way before (just playing around, of course, since there was no practical way to mount them permanently that way), and from that little bit of comparison, I would say that that they aren't as refined as the little BGs, mainly in the top end, but they're just filling a box, taking up space these days with little chance of coming out unless I find something "interesting" to do with them.

So, what do you think? Will that be long enough to engage the benefits of the line array? Will I need a similar line of woofers next to them or will I be able run just one good woofer from 200Hz down? Another question, with 5 on a side, and I believe they are around 4Ohm, what sort of wiring config would give me the best load for the cheap Pio receiver that will be running them? The Pio handles 4Ohm just fine, but I've burnt another out trying to crank up one at 2Ohm.

I've thought about those Datyons you've used. They seem about perfect for making a line (too bad they aren't a few inches longer at that price though, eh?). Your line of six is probably just about the same length as my line of 5 Monsoons would be. And those woofers, I really can't judge their size from the pic (4"? 6.5"?), are they Dayton aluminum cones. Is that an OB or do you have some enclosure work behind the baffle. Most importantly, how does it sound and how satisfied with it are you? I certainly looks sweet.

[karma]

i just picked up 94 Monsoon drivers.

should look like this when finished. im new to line arrays so i cant help you. do you have a pic of your speakers?

[Kensai]

Not offhand, sorry.

Mine are the big, metal shelled planars that were the satellites from their last line of PC speakers.

[karma]

ic nice

[Kensai]

Maybe I need to back away from specifics and see if I can find some general theory on line arrays. Links anyone?

I have at least one other possibilty for making a line starting from components I have on hand right now. I need to know how long is long enough. I need to know how far apart I can allow the accoustic centers to be. I need to know if/how to taper off the high end response as the drivers move away from the center of the line. That sort of thing.

My other concept involves Kenwood, full range, 6"x9" car speakers (single driver, whizzer cone, possibly moded with phase plugs). I have 4 available right now and am thinking of gathering more up in the near future. Thinking maybe 5 in a line (with the 9" measurement in the vertical plane) which would give a 50"-55" line. I could phase plug mod the center one, put a low pass to taper all the others off a bit from full range, and then either put a lower freq low pass on the top and bottom drivers or simply cut off their whizzers.

Any thoughts? Links? Flames? I'll take anything right now.

Kensai

[Dr.Faustus]

Start here:
http://www.jblpro.com/pub/tour/conve...paper_5304.pdf

Then see if you can find Jim Griffin's Line Array White Paper. At the moment I can't find it online anywhere, but you might be able to get it from the source - http://www.gr-research.com/

FWIW,
Dr.F

[Bose(o)]

Totally dude, just hook them Monsoons up and augment the bass from 200Hz. down with an OB woofer. Use the standard design config of a dipole woofer and you'll have a very sweet sounding system.

Also, WHERE ARE PPL GETTING MONSOON DRIVERS!?!?!? I would love to pick some up, it's just that I sold my PC Monsoons and would seriously consider line arrays with such a driver.

[Kensai]

Bose(o),

Thanks.

Had mine laying around for awhile now. I bought a set of PM7s for like $35 shipped way back since I wanted to try them out. Loved them. Decided I wanted to play with a bunch of them, so when I found them for $15 close out right after Monsoon announced they were getting out of the multimedia market, I got 3 more sets (I initially had each PM7 set up as one point of a 4.0 system). Not too long after, a new Circuit City opened near where I was working at the time and they had one set of PM14 in a shredded box that I snuck out from under them for about $50. All the subs and amps are gone from all that over time, but I've got 8 gray panels and 2 black panels.

Planning to put the black in the center. Thinking to run that straight out and then run the pair above and the pair below each in series so that they're running a bit quieter than the center one. That should be good, right?

Kensai