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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => LAB Lounge FUD Forum Archive => Topic started by: Andrew Reggie Thomas on April 26, 2004, 04:33:13 pm

Title: question about my crossover
Post by: Andrew Reggie Thomas on April 26, 2004, 04:33:13 pm

So the band got a crossover and apparently the instructions aren't enough for me cuz here I am.  First off we purchased a cx2310 behringer. It's 2 way stereo 3 way mono with a seperate sub woofer input.  Right now I run 3 way mono and have the jbl 18's plugged in to the low input, 15's for mid and the 12's for the high's. I'm wondering if I should plug my subs into the sub woofer input instead of the low input or if there's even a difference at all.  

Also my Yamaha S115IV's say crossover at 1.7 KHz. should I just go with that.  
And one last thing is the frequency response of the S115IV's is from 55 Hz to 16 KHz. and on my Yamaha s12e's the frequency response is 65 Hz. to 14 KHz. To me it seems the  15's would make better tops. Should I leave them set up the way they are, switch them over and have the 12's for the mids or just run the subs and the 15's and ditch the 12's.

...................Thanks Reggie...............................

Title: Re: question about my crossover
Post by: Baron Gray on April 26, 2004, 10:19:22 pm

Hi Reggie
I don't know your cabs so here are a few questions.
Are the cabs bi-ampable?
How are you stacking the 12s with the 15s?
Do they both have the same horns?

When you say inputs, you are actually referring to the outputs of the xover.

I believe that unit is designed so you can run 2 way stereo with a mono sub send or three way mono with a seperate sub send.

The only advantage for your setup, I can think of, in using the dedicated sub send is that the scale on the crossover frequency knob, for the sub, is a bit more accurate than the full range knob. Ie it goes from 10hz to 350hz instead of 10hz to 1000hz or whatever the scales are.

A big issue I have found, when I played with one of these, was that the indications on the knobs are very rough indeed so some pink noise and an RTA would come in handy to set your basic xover points and levels then mark the dials with some liquid paper.

Another problem with this device is that it does not have any time alignment features so particular attention must be paid to speaker positioning.

Have a look at the questions and get back to us.

Baron

Title: Re: question about my crossover
Post by: Mike McNany on April 27, 2004, 12:58:51 pm

Mad Mixer wrote on Mon, 26 April 2004 16:33

So the band got a crossover and apparently the instructions aren't enough for me cuz here I am.  First off we purchased a cx2310 behringer. It's 2 way stereo 3 way mono with a seperate sub woofer input.  Right now I run 3 way mono and have the jbl 18's plugged in to the low input, 15's for mid and the 12's for the high's. I'm wondering if I should plug my subs into the sub woofer input instead of the low input or if there's even a difference at all.   Also my Yamaha S115IV's say crossover at 1.7 KHz. should I just go with that.   And one last thing is the frequency response of the S115IV's is from 55 Hz to 16 KHz. and on my Yamaha s12e's the frequency response is 65 Hz. to 14 KHz. To me it seems the  15's would make better tops. Should I leave them set up the way they are, switch them over and have the 12's for the mids or just run the subs and the 15's and ditch the 12's. ...................Thanks Reggie...............................

Reggie,

I have one of those crossovers and I think they are the best bang for the buck new under $200, especially at $80 ;>)

You have a combined problem. First, you should NOT use a 2 way cab as a mid cab NOR should use a 2 way cab designed for mids & highs as a high cab WITH the other 2 way. The Yamaha IV series have a horn driver that is MUCH better than the E has, one of the reasons it costs 2/5rds more. NEITHER are bi-ampable from the factory so you can't avoid going via the internal crossovers. Lots of other reasons, too much to waste bandwidth, not worth rewiring for that.

Relagate the S12Es as a practice PA, monitor duty, or as delayed cabinets out in the crowd for an outdoor venue.

Simply use the S115IVs over the subs. You'll have MUCH better highs in this case. That means CLEARER vocals, since the horn driver is carrying most of the vocals. Let the Yammy internal passive crossover do it's job, it's fairly effecient AND effective.

Next, the crossover. Select 2 way stereo mode. Use one side IF you want a mono system or both sides for stereo. Select the lower range (X1 on BACK) for the high/low frequency selector knob. Turn that to about 100Hz to start with (both sides for stereo). Turn the Mono Summed Sub out frequency knob to as low as it goes. Otherwise it will act as a low CUT filter sending the frequencies below that to an unused output. (Yes, you CAN use it as such.) CAREFULLY check the multiple use silkscreened markers for the mode you select. Use the (stereo mode) HIGH output to the Yamaha tops and the LOW output to the JBL 18" subs. The CX2310 is the one cheap crossover than has the range to do this. There you have it, a simple tops to subs split out.

Yes, the high/low frequency knob isn't as well marked for this range as desired. But you should further tune the crossover frequency by ear or pink noise or, better, both, for the best sound ESPECIALLY with mismatched brand speakers. Don't know about the JBLs but Yamaha had a PASSIVE (yup, passive) standalone crossover for the IV series that was at 90Hz. I would NOT go above 120Hz crossing with your speakers. Keep in mind the output levels will affect the "apparent" heard crossover point from the SPL summation around the crossover point. So that will affect the heard sound, along with the fact that subs are often less effecient than tops, it just takes more power to hear lower frequencies, AND the tops aren't wasting power or cone range with those lower freqs going to the subs. And variations between the sub and tops' amps at to that.

Settings on MY CX2310 (pros bear with me, cobbed together bar band system SLOWLY being upgraded):

Previously, OLD, OLD, (did I mention, OLD!) Peavey SP2 tops powered with 235 watts each, Behringer B1800X subs powered with 500 watts each, Crossed at 105Hz, Crossover outputs set with high out 4dB down.

Currently, NEW Yorkville U15 tops, same subs, same amps but the U15 is 4 ohm for 350 watts to each, dropped crossover freq to 85-90Hz.

And for those in the know (OH, MY, those U15s underpowered! but so are the subs!) New PLX3002 on the way, first on the subs for 700 watts at 8 ohms each (till a PLX3402 or a bridged 1602 is afforded for 800 watts each) and the old sub's amp, RMX2450, to the tops for 650-700 watts each at 4 ohms.

boomerweps

Title: Re: question about my crossover
Post by: Andrew Reggie Thomas on April 28, 2004, 09:41:52 pm

Well Boomer you cleared everything up perfectly.  I think you were the one that said I should buy that type of crossover a few months ago.  Last Saturday was the first time we used the 12's on the house and man were they muddy. Back  to the monitors they will go.  I also couldn't find in the manual that bit about the mono summed sub out frequency knob acting as a low cut so thanks on the heads up on that also.  I never was to sure if I should plug the sub into the sub out or the low out, that is my biggest problem.

The band recently ran into a chunk of change and I'm going to try my best now to stay away from foolish purchases.  As for my JBL Subs I'm not to sure about them either. I really can't find any info on them all I know is they aren't passive and they are 600 watts each.  I noticed you attenuate your highs -4 dbs.  Do you do that on your crossover or on the amp's input Knobs?

Thanks Reggie

Title: Re: question about my crossover
Post by: Mike McNany on April 30, 2004, 04:34:21 pm

Hope you don't think I misled you on cheap crossover choices ;>)

"I also couldn't find in the manual that bit about the mono summed sub out frequency knob acting as a low cut so thanks on the heads up on that also."

You're welcome. It's NOT mentioned in the manual but since the mono summed sub frquency selector is always active in either mode, it's not TOO hard to figure out that it will affect the low outputs IF you've had some experience with crossovers before. They really should mention it in the manual.

"I never was to sure if I should plug the sub into the sub out or the low out, that is my biggest problem."

You CAN do either. WHAT!!!!!!!!
I know a couple guys who use the mono summed sub out to their subs and use the HIGH out for their tops. Then they can UNDERlap the crossover point. They have to dial in the monosummed sub out point on the one knob and then the high/low crossover point on the other. In this case the LOW out is the unused output, sending any of that away~. So the high to low point would have to come close to the sub out point. It's hard to get them matched this way. It depends a LOT on the heard result vice visual knob settings. Too hard for me. I just run simple stereo using the high/low frequency selection as the only variable ;>)

"I noticed you attenuate your highs -4 dbs.  Do you do that on your crossover or on the amp's input Knobs?"

I basically run my amp attenuators full on, again for simplicity. So I make the adjustments on the crossover output levels. And that's to allow for different amps and different speaker efficiencies.

Boomerweps