Topic: Which boxes for this 500 cap room? (Read 9999 times)

Marsellus Fariss · « **on:** February 04, 2011, 10:19:23 PM »

I started a post several weeks ago about this in the old forums and now we're getting down to a final choice and it's very important decision. It looks like the old forums aren't very active anymore so I hope it's ok that I post once more about it in the "new digs" Cause we really need to get it right. We won't get the chance to do it again for years and years. Sorry if it's not alright.

Requirements:

Room is about 50'x60' w/ low ceilings. There's pics in the old thread if you follow the link. Capacity is 500.

Genre's are everything from songwriters and bluegrass, indie rock and commercial kinda rock. No metal, DJ's or HipHop. Acts range from local to C nationals. About half of the acts bring a BE.

SPL needs to be capable of 105dbA 30' back at FOH or 115dbA(ish) at 1 meter without toasting drivers. This only happens when BE's step on the gas and it's maybe one or two shows a month but it needs to be safe.

Coverage should be 90 or less a side using two boxes to avoid shooting into walls too much.

Budget is 2kish a box.

Current power is 6 Crown K2's and processing is an XTA 2x4, an analogue Ashly Xover if needed and DN360 at FOH. We're keeping the current 2X15" subs for the moment.

Candidates: (two a side)

EV Qrx 153/75
EV Qrx 212/75
EAW LA460
JBL SRX 725
JBL SRX 738

Other then that I'm keeping my eyes out for some used X-array, or KF650's but none are available at the moment.

Am I on the right track?

Link to old thread: http://http://srforums.prosoundweb.com/index.php/t/63946/0/

Duncan McLennan · « **Reply #1 on:** February 04, 2011, 11:00:57 PM »

I think waiting for a used pair of 650s is by far the best option, and worth the wait.

If that's not an option, I'd take the QRX 212.

Marsellus Fariss · « **Reply #2 on:** February 07, 2011, 10:59:10 PM »

It's looking like it's gonna be LA460's Two per side. I think we'll be happy with them. Long term SPL is 130db @ 1 meter and that should give us the 105dbA 30' back for the occasional BE who "needs" it. I tried hard to find some 650's but none could be found used. Also the 460's are cheaper used then the Qrx and have a little bit more friendly name for riders. Not that I've heard of many complaints about EV. At least not form people who knew 1/2 of what they where talking about. Also, we couldn't find any Qrx around to listen to but we're very familiar with 460's.

Can anybody offer me advice on powering and tuning these guys? They'll probably be run full range for a little while to save time but bi-amping is gonna happen.

Power is 4x Crown K2's. Processing is XTA.

DBA · « **Reply #3 on:** February 08, 2011, 02:53:34 PM »

Full Range:
I would try to power them at 8 ohms stereo with your K2's. This would give you 500w per box which should be more than enough for your quiet shows and not let the smoke out for the other shows (as easy) that would tend to push them. This would leave you with 2 spare amps. (addtional sub amps, spares?)

Bi-Amp/High Output:
Bridge the lows 2 cabinets per side on one amp per side (4 ohm bridge for the amp). This would yeild 1250 watts per box on the lows. Use One amp to drive all of the high end 2 boxes per side. This would yeild 400watts per box on the highs (on paper) which is more than 2x the rated power for the drivers.

This option would leave you with one spare amp, a MUCH higher chance of destroying the speakers, a chance of overheating the amps (since they are passively cooled (otherwise a great amp)) . I would not go this route unless solution A was not "enough".

Bi-Amp/Lower Power:
Run the same thing as scenario A on the low end and Scenario B on the high end. Make sure the amps never, ever, ever hit anything close to peak on the high end. Limit and keep the gain on the amp panel at a "bulletproof" setting. I know this is not a "real answer" but you can set the gain structure so that it's virtually impossible to cook the drivers with the input attenuators on the amp. Given the gain structure is correct up the chain.

Tim Talbot · « **Reply #4 on:** February 08, 2011, 05:02:01 PM »

I would recommend the JBL SRX725 everyday.... truly stunning

Marsellus Fariss · « **Reply #5 on:** February 08, 2011, 06:31:24 PM »

Should I apply the PEQ tunings that EAW has for bi-amping if I'm running passive?

Tim Talbot · « **Reply #6 on:** February 08, 2011, 06:47:00 PM »

Quote from: Marsellus Fariss on February 08, 2011, 06:31:24 PM

Should I apply the PEQ tunings that EAW has for bi-amping if I'm running passive?

I take it you mean JBL and not EAW ... ?

If so have a look on there site and your find the PEQ settings, one for bi-amp and one for running them passive.

Marsellus Fariss · « **Reply #7 on:** February 08, 2011, 08:13:45 PM »

No the EAW. They don't only offer tunings for bi-amping the 460. Though I assume I should start with the same PEQ tunings as the crossover shouldn't change things THAT much.

Tim Talbot · « **Reply #8 on:** February 08, 2011, 08:23:22 PM »

You might be shocked just have much a different crossover(s) effect / change the sound

David Morison · « **Reply #9 on:** February 10, 2011, 07:34:21 AM »

Quote from: Marsellus Fariss on February 04, 2011, 10:19:23 PM

Coverage should be 90 or less a side using two boxes to avoid shooting into walls too much.
<snip>
Candidates: (two a side)

EV Qrx 153/75
EV Qrx 212/75
EAW LA460
JBL SRX 725
JBL SRX 738

None of those will do 90 degrees coverage per side using 2 boxes without quite a bit of overlap - most of them are 75deg horizontal per side. Maybe look for 2nd hand EV Phoenix (45 deg per box IIRC)?
Just a thought,
David.

Marsellus Fariss · « **Reply #10 on:** February 10, 2011, 03:44:20 PM »

Yea It looking like shooting some into the wall is gonna be unavoidable as we'll probably wind up with a 60 degree box. I suspect we're gonna change the hang in the room and hopefully we can get something w/o TOO much combing and problem reflections. We're shopping for used at the moment so unfortunately we can't be too picky. Doesn't seem to be a whole lot of good used stuff out there at the moment and the calendar is looming on us. I don't think a 120 pattern will be too problematic. We've been dealing with awful floor and ceiling reflections up till now because the old JBL tops are flown sideways and the so the horns are oriented 40x120!

DBA · « **Reply #11 on:** February 11, 2011, 12:41:03 PM »

Marsellus,

Would a pair of 90* or greater degree higher output boxes get you where you need? Something like a pair of KF-850? But thinking on it, those boxes are huge.

Im just trying to think of something that would keep you from having to use 4 boxes.

Im just using the KF-850 as an example, but I really don't care for how they sound. They get up and get really loud but I think they suck SQ wise.

David Morison · « **Reply #12 on:** February 14, 2011, 08:06:23 AM »

Quote from: Whit Hutchinson on February 11, 2011, 12:41:03 PM

Marsellus,

Would a pair of 90* or greater degree higher output boxes get you where you need? Something like a pair of KF-850? But thinking on it, those boxes are huge.

Im just trying to think of something that would keep you from having to use 4 boxes.

Bad example - 850's are 55degree boxes, so he'd have to use 4 total to get the necessary width of coverage - and it'd be massive overkill in size, weight etc.

If there was such as thing as a 90 deg version of that class of speaker, then maybe, but most speakers designed like that are also designed with narrower coverage to allow use of more than one or two per side.

Cheers,
David.

Tim Talbot · « **Reply #13 on:** February 14, 2011, 02:09:47 PM »

Am surprised that 850 is that wide.... most box's like that are 25 - 35 degrees. JBL SRX725 are quite wide & loud

Mac Kerr · « **Reply #14 on:** February 14, 2011, 02:43:50 PM »

Quote from: Tim Talbot on February 14, 2011, 02:09:47 PM

Am surprised that 850 is that wide.... most box's like that are 25 - 35 degrees. JBL SRX725 are quite wide & loud

If "most" large format speakers from the 1980s are 25 - 35 degrees would you include a link to some information about them?

Mac

Tim Talbot · « **Reply #15 on:** February 14, 2011, 06:36:21 PM »

I said ''Am surprised that 850 is that wide.... most box's like that are 25 - 35 degrees'' never said anything about a date....

RES 5 - 25 degrees
MSL 4 - 35 degrees
Void Prime - 25 degrees
etc etc

chuck clark · « **Reply #16 on:** February 14, 2011, 07:59:41 PM »

It's hard to go wrong w/ QRX Or SRX, but have you looked at Looked at Turbo TDX? The reason I suggest is they come in a 60 degree horn. Another spkr that I've had wonderful results with is the Community SLS stuff.
You'll want some subs but that shouldn't be a problem with your moderate volume requirements.
I recently did a 2000 seater with a blues act with a pair of the TXD turbo's and some Peavey sp 218 subs. That's a 90 degree horn w/ 3" voice coil per side for highs, 2 15's w/ 3" voice coils for mids per side and 2 18's w/ 4" voice coils for lows per side. A dbx driverack and 2 QSC PLX 3402's for power. Bi-amped between the subs and tops and crossed at about 80 hz. Eq to taste and no fancy settings. Almost too easy. All happy- muso's, promoters and me. Not the loudest rig, but a full rich quality that pleased all.
-Oh, A &H 2400 out front. Happy sailing!

Marsellus Fariss · « **Reply #17 on:** February 14, 2011, 09:44:33 PM »

Well we've bought 4 EAW LA 460's and they should be here Thursday. We'll hang 2 a side and power them passive for now off two bridged K2's for 1250watts per cab at 4 Ohms. It's a little more power then I'd like to feed them but that's not such a big problem. We'll bi-amp later when time allows. I would have rather had found some other MSL4's or some 650's but it wan't to be. We REALLY had to get moving on something. I think we'll be happy with the 460's. They array well, have the SPL we need, it's a three way like we prefer and can be bi-amped or run passive. They're be a huge step up from what we've got and there's a few spare drivers around town if need be.

So if I'm to believe EAW's "Virtual Array Technology" I shouldn't have to splay these cabs at all to achieve good coverage w/o combing problems?

Tim Talbot · « **Reply #18 on:** February 15, 2011, 06:00:21 AM »

Its called tight packing and i wouldn't worry to combing or phasing between cabinets no.

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Author Topic: Which boxes for this 500 cap room? (Read 9999 times)

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