Crossover Y/N

[Jack Damage]

Question: do you "really" need a crossover if you want to run subs? I have heard both yes and no..some Sound guys said they use a dual channel EQ and just cut the higher frequencies from the subs to achieve the "sub" effect..and some say "yes" you need a crossover..these are the ones who work in the music stores that obviously want to sell a crossover..thanks for any adivce..Jack..:robot:

[DAS]

You can kinda' do what you're talking about with EQ, but for overall sound quality it's not a great idea. EQ's (especially cheap ones) tend to introduce a lot of phase shift problems into the signal when there's a lot of cutting and boosting. Further, a graphic type EQ is only going to provide about 15 dB of cut -- potentially less between the bands. That's not so bad right around the crossover point, but as the frequencies get further from it you want significantly more cut than that.

Crossovers use different filters to achieve the desired results with far fewer negative side effects. They are really the "right" way to do it. I can be more specific about this if it will help, but suffice to say that if I were in your shoes I would buy a crossover.

[jpleong]

It depends. How's that for an answer?

If you've got active subs, chances are there is a built in crossover already. Models like my (discontinued) JBL active sub have a pre-set crossover. If you're not concerned about the crossover point, this is fine. If you want more control over what frequencies the sub works with, you'll need a crossover.

The 31 Band EQ thing works if there's no dedicated crossover available but I'm wary of that kind of use. The primary issue is the number of filters that need to be engaged. A crossover generally will use one or two pass-filters (depending on whether it's 2-way or 3-way) whereas an outboard EQ will have anywhere between four to 33 filters. Generally, the more filters you have, the more interaction you'll have between filters in the phase/polarity realm. If you've got a high quality EQ (like an Ashly or Klark-Tecknik), that's not a super big problem -but if you're using a less expensive EQ there is greater likelihood of warping the sound (which is sometimes better but usually worse). Some EQs also have built in HPF (variable or fixed) which could "replace" a crossover but you'll want to see how steep the filter is -too gradual a cutoff point makes it useless.

JP

ps- whoops! DAS- you beat me to da punch!

[Jack Damage]

So then the crossover will be the last thing in the chain before the signal goes to the subs right? Jack

[jpleong]

It's the last thing before the amps.

Mixer -> EQ/Compressor -> Crossover -> Amps -> Speakers & Subs

Of course, if using active speakers, the amps are built in.

JP