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Active crossover

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Active crossover

Postby forumuser661816 » Tue Nov 20, 2018 2:06 pm

Four piece band with bass, edrums, gtr, three vox. Use a rcf m18 dig desk which has one output and six aux. Our speakers are two peavey subs with a warfedale amp plus 2 x EV full range active tops. The single output from desk is split with a splitter cable - 1 to tops left and right the other to sub amp left and right. We've noticed that the sub amp is not getting a strong signal and think it's down to the splitter?
Do I need to get an active crossover?
I have looked at an entry level behringer cx 2310 but it only has one sub output.
I'd greatly appreciate any advice on this setup. Tia.
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Re: Active crossover

Postby Wonks » Tue Nov 20, 2018 2:49 pm

It would help us if you gave the model numbers for the tops and subs and power amp.

You should either have a crossover of else have high pass filtering in the tops and lo pass filtering in the subs. Without this, the tops will be trying to cover the same frequency range as the subs, which can both make the low mids/high bass rather excessive and also it doesn't let the tops make use of the extra power that not having to reproduce the bass frequencies would give.

It is very likely that the subs have built in passive low pass filters, but the power amp is still amplifying a full range signal, which is being wasted by the passive crossover.

The tops may have a switch to activate a high pass filter, but without knowing the model, we can't tell.

The tops probably have a 'through' or 'out' XLR socket. This will simply be paralleled with the input XLR, and if using this, it would be exactly the same as using a splitter cable from the mixer.

The mixer's main output should be able to drive several line level inputs in parallel,; you'd probably have to go over four before the overall input impedance seen by the mixer's output was low enough to cause driving problems. Also, the signal level would be the same for the tops as for the power amp.

The Behringer CX2310 will do just what you want, though I have never used one so have no idea what quality of signal it will produce. You do not need to use the mono sub output - though it's very unlikely the subs will output any worthwhile stereo information, so you could happily feed them the same signal unless you use definite left and right stereo bass signals. If you are using the CX2310 to feed two tops and two subs, both with stereo signals, then you simply set the crossover frequency range to 'low' on the CX, then set the frequency to a suitable value, somewhere in the 80-125Hz area. The two main outputs will then have the correct split signal and there is no need to use the mono sub output.

If you had a rig consisting of discrete low, mid and high frequency units, then you'd need to use the mono sub output, but in your case, you don't.

The crossover setting will depend on the frequency range of the tops and subs - which is why knowing the models is important.
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Re: Active crossover

Postby forumuser661816 » Tue Nov 20, 2018 7:19 pm

The amp for subs is a wharfedale W Audio TPX 65. The Ev tops are ekx 15p. Subs are peavey hysis 115xt
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