Do i need a crossover?

Question

i run a dj system, i have a mackie fr2500, gem3950 amps ev eliminator subs, rms 15's w/ horns berringer fbq1502 eq, berringer mixer, the eq gave distinction of frequencies, but lost total headroom(volume) would i benefit adding a crossover or not?

Answer 1

I am not familiar with all the model numbers, etc., that you mentioned, so let's discuss a generic audio system.  Your turntables and microphone should feed to your mixer.  The mixer sometimes acts as a preamp, sometimes not.  Let's assume yours does.  The eq is usually hooked to the mixer/peramp in one of two ways:

1) It can be hooked into the "monitor loop"; or

2) it can be hooked between the mixer/preamp and the power amplifier.

If the eq is hooked up in the second manner, the advantage is that you still have your "monitor loop" for tape recording or other purposes.  But the disadvantage is that the eq now is acting as a preamp, and it affects the total level fed to the power amp.  Some power amps have a volume control which may allow you to compensate, but I am betting you already have yours (if you have one, that is!) maxed out.

You have two possible solutions:

1) If you can afford to sacrifice your "monitor loop," (i.e., you don't need to tape record), try hooking up the eq that way; or

2) Add another preamp stage.  (Alternatively, you could add a more powerful power amp...)

In reality, I'm betting your system is already loud enough to rattle the walls, so losing a dB or two for the eq is probably only a paychological problem anyway...

As to adding a crossover,  it is generally not wise to simply hook all the drivers (your woofers, your midranges, and your tweeters) in parallel.  So, yes, a crossover would be a good idea, ensuring that the power in the various frequency bands goes to the appropriate speakers, and making sure the bass frequencies don't blow out your tweeters.  Crossovers come in two types:  passive and active.

Passive crossovers are the simplest type, and consist of coils and capacitors wired in such a way as to send the appropriate frequencies to the appropriate speakers.  The advantage of them is that they are simple and easy to hook up.  The disadvantage is that they eat up some of the amplifier power.

Active crossovers work on the same principle, but are smaller, because they do not have to handle the power of the power amp.  They are hooked between the preamp and the power amp.  The disadvantage is that you will need a separate power amp for each frequency band. (Using a 2-way crossover, this would be called "biamping" and using a 3-way crosssover, the result would be "triamping.")  The good news is that the amps for the mid- and high- frequency bands won't have to be as powerful as the amp for the bass -- and as such, not as expensive.

A good local live music dealer should be able to get you hooked up with the right equipment.  Good luck!

Answer 2

i have a similar set up for my home...mackie 1400, for my mains and a toa 1000w for my subs, i had a dual 31 band eq but had a similar problem as you do. i ditched the dual 31 band and got a x-over and a single band eq and it made it all good.....now i just gotta find my feedback issue...grrrr.