Budget centerfills

J

Jeff Kenney

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Mar 4, 2013
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I need a low profile budget centerfill.
Was toying with the idea of making a pair of b&c 12" coaxials to get er done.

1. Is there anyone out there that makes crossovers for off the shelf drivers so I don't have to do it myself?
2. Are there any amplifier modules (perhaps even bi-amp modules w/ simple dsp's in for xover duty?)
3. Any recommendations?

I have a few powered box's that we use - but a 2 way is just to high for this application.
 
Re: Budget centerfills

Have you bought the driver's yet?


I think a 12 coax is a bit to big for lip fills as well. I would be looking at 8" boxes.


I would do 2 of these:
http://www.eminence.com/speakers/speaker-detail/?model=Beta_8CX

and one of these:
http://www.eminence.com/speakers/driver-detail/?model=PSD200216


And wire the mids in series. You'll have a 16 ohm box so you can string a bunch of them on one amp channel across the front of the stage. Eminence will sell you a crossover for it too. Probably want to call them about what XO to use.

I know these aren't sexy drivers, but they are very solid, and sound great.
 
Re: Budget centerfills

Powersoft makes a bunch of modules.
I think that for a small run, bi-amp with built in dsp would make more sense than designing a passive.
Or you could do a very simple passive, and do a single channel module, with built in digital EQ.

+1 on 8 vs 12, but I tend to think in terms of my shows, and don't know yours.
 
Re: Budget centerfills

12" because there is significant void from the mains for a good 50 people in center AND this is for only my shows which are EDM. So I want a little more balls.
 
Re: Budget centerfills

It looks like those powersoft modules would be pricey. Doesn't make sense to build something that costs more than going out and buying a 12xti
 
Re: Budget centerfills

The Powersoft modules are VERY pricey. Nothing budget there. Even for EDM, I think a decent pair of 8's would be fine. You're going to high pass them anyway, so why go the extra height/expense? Even on EDM events, I still hipass my fills at 250hz. The low mid was from the DJ fills & main hangs give plenty of mid bass down front, and with the subs crushing the people up front, they won't notice a little gap anyway. I'd be more worried about a beefy HF driver than lows in a FF. I'd look for a pair of decently efficient 8's, and a nice 1.5" exit horn. I've had good luck with the JBL 2431.




Evan
 
Re: Budget centerfills

Right you are Tim!

We are really trying to fill where the main hang HF does not go. Introduce more than that and you toss in mo' problems.

But, to paraphrase, all sound is local. If patrons do not see themselves close to a box they are somehow shortchanged.
 
Re: Budget centerfills

Jeff Kenney said:
I need a low profile budget centerfill.
Was toying with the idea of making a pair of b&c 12" coaxials to get er done.

1. Is there anyone out there that makes crossovers for off the shelf drivers so I don't have to do it myself?
2. Are there any amplifier modules (perhaps even bi-amp modules w/ simple dsp's in for xover duty?)
3. Any recommendations?

I have a few powered box's that we use - but a 2 way is just to high for this application.
Click to expand...


http://bcspeakers.s3.amazonaws.com/2013/02/12/16/15/05/196/file - just keep the box volume the same and adjust the shape cabinet to suit your needs. The 12HCX76 is an excellent driver. Its what's in my 12" wedges and they sound great.

The crossover design is included, but you may need to find some one to build it for you - perhaps someone on the forum could help (?)
 
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Re: Budget centerfills

I've been tinkering around with this same type of project. I've initially put a couple of B&C 12CXN76s in 1 cu' truck sub boxes I got off Amazon for $38 each just to see what would happen. These I kept sealed. It's mostly for DJ apps with plenty of subbage so I'm not too concerned with correct tuning.




B&C's recommended crossover is 1200hz @ 12dB so I threw a couple of them together - using shelving filters on a iNuke 6000DSP to balance the drivers and do a few quick EQ adjustments. These are quality drivers and they don't need much.



Initial results are promising, but I think I'll actually use 1 1/2 cu' truck sub boxes from the same outfit for the final project and port them. The box on the B&C website for this driver is almost exactly that size and they give their recommended port dimensions too. Might as well do it their way ;) The 1' boxes are a little shy in lower mids for karaoke shows (one of my apps) and they are so ridiculously small that they are too small to be taken seriously. I'll probably end up bi-amping them too, but what I've already got isn't all that shabby.

Total cost per box is around $500 including drivers. My apps are contemporary DJ and high energy karaoke - very dense material and not subtle stuff. I'm not at all concerned about delicate brushes on rides or feathery female singers.

Peter do you think that crossover for the HCX76 would work on the CXN76? I'm not a crossover designer, but I could make those if they'd work.
 
Re: Budget centerfills

Bill Hornibrook said:
Peter do you think that crossover for the HCX76 would work on the CXN76? I'm not a crossover designer, but I could make those if they'd work.
Click to expand...

Hi Bill,

The HCX and CXN series use the same HF driver, effectively: there are small differences, but a crossover that works for one should work for either. The only thought I'd have is that the large horn of the HCX may make you want to shift your XO point down. The driver is very well loaded and the woofer is shadowed by the horn, so the driver can probably take the excursion and you want to keep HF from the woofer from bouncing around between the cone and the horn. Attached is a cross reference list so you can see just how stout that HF driver is.

Screen Shot 2015-03-16 at 6.14.51 PM.png
 
Re: Budget centerfills

Bill Hornibrook said:
Peter do you think that crossover for the HCX76 would work on the CXN76? I'm not a crossover designer, but I could make those if they'd work.
Click to expand...

Bennett is correct, the crossover will work for both; however the crossover is usually optimised for a particular driver including the effects the horn has on the response.

In this case one driver uses the cone as the horn and has a nominal pattern of 80 degrees, the other has a separate 60 x 40 horn.

Sooo while it may work, it may not be optimum because the frequency response of the two horns/drivers is different – see below.
 

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Re: Budget centerfills

Thanks for your responses gentlemen. I may make the B&C crossover but am hesitant because the horns are different. If I stay passive I may just go with what I've got and do the balancing and EQ in DSP - which has come out pretty darned good really.

To Jeff Kenny: If it's your desire to just "get 'er done" what I've put together will definitely do that for you, and probably accomplish what you want as long as you are highpasing them above (say) 150hz or so.

They really don't even qualify as a DIY really - more like an "assemblage" ;) I put them together in an afternoon. I used decent inductors and caps though - 400v Solens and 14 AWG Erse air core inductors. These were meant to be prototypes so I just stapled them to the bottom of the cab.



To give you an idea of their size, I took a pic of one next to a JBL SRX-715:



As for me, I'm movin' on up to a 1.5 cubic foot cube for mine :D They just plopped on my doorstep a few days ago. These are actually a little more - $40 each! - 3/4" MDF with some kind of black covering on them. It's not rat fur but not far from it either. No biggie for me on a box this tiny. Well made though for what they are. How on earth something this decent can be manufactured in China and dropped onto my doorstep for just $40 is beyond me.

I've got a lot on my plate right now but will get back to this project in a couple of weeks hopefully.
 
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