Crossover Settings

[Splosh 0]

Right, i have been umming and ahhing about posting this for a while....

 

Back in November, I purchased a Crossover (Decided to after a chat with Gary at a SEDA Meeting - He probably won't remember).........

 

Anyway, when I purchased it, I was talking with the sales guy (who was very helpful - i think)...... We was talking about Hertz and Mega hertz and I am damm sure he told me that bass travels slower (yes already knew that) and at around 40 HZ or 400 MHZ .......

 

Anyway I took this as gospel (bad mistake i know) and I thought that I had set the crossover to split at that level (400 MHZ) Anyway, I quickly got the inkcling that this was not the right way to set the crossover up, especially as I was still gettting some bass outta my tops....

 

To cut a long story short I have been playing with the crossover since December and have not yet decided where I think the dial should be set..... I belive that at the moment I have it set on 20HZ........... The sound reproduction is good, but I am still not convinced that I have it quite right......

 

Any suggestions / ideas???

 

 

Bleak description I know, but you boffs on here will wangle me something i am sure.....

 

 

Splosh

[DJ Marky Marc 0]

depending on your speakers you should have it set arround 120 to 180hz in a two way setup

 

not Mhz

 

20hz is the bottom end cut off you can't hear things that low normaly....

 

everything above 120 goes to your top amp and everyting below goes to your base amp.

 

 

[superstardeejay 0]

Yep I agree with Marky. I also use 120Hz as a rule of thumb in a two-cab setup.

[norty303 0]

Depends on the cabs you're using, whether the tops can play cleanly down to the required level, whether the subs can play cleanly up to the point you want to cross them at.

 

If it's got a hi-pass (low cut) feature you really should be employing that as well

[Jimbo55 0]

Ideally there should be a response curve graph (or spec sheet) that will show you the optimum frequency response of both cabs (see manufacturers web site). It should then be fairly easy to set the crossover but as suggested already 120hz is a good average in the event you do not have these.

 

Jimbo

[Andy Westcott 0]

I use 200Hz at 18dB/octave between my bass units and my midrange.

 

Most bass units can reproduce reasonably well up to 500Hz and beyond, but beware of exciting cabinet resonances at these upper bass frequencies, which can colour the sound in an unattractive way.

 

Most important to consider is what the midrange can handle in terms of lowest frequency. If a small dedicated midrange unit is used, the lowest recommended frequency could be as high as 500Hz.

 

On the other hand, if you are usin a full range speaker anyhow, and are simply adding a bass bin, you might be better off setting the crossover as low as 80 Hz.

 

This question is almost impossible to answer correctly without knowing your speaker configuration, so if you can let us have some detailed info on your bass units and your midrange, we can make better suggestions for you. http://www.dj-forum.co.uk/html//emoticons/smile.gif

[norty303 0]

Also, be careful of phase shift when using any filter that isn't 24db/oct as every 6db/oct introduces 90deg of phase shift which may need to be compensated for.

 

If available Linkwitz Riley 24db/oct filters are about all you could desire unless you're doing something special

[superstardeejay 0]

And bear in mind your bins may have a low-pass crossover in there already which may not be user-removeable, it would be a pity to crossover so the bins are being fed frequencies much higher than the internal crossover. Not difficult to remove but not all DJs are ok messing with wires and PCB's.

 

Alot of mobile guys like to use a crossover to take bass well away from the tops in order to eke out every watt from their top cab amplifier, minimising clipping on that amp....and aiming for SPL's rather than pure quality...driving each speaker only at its optimum frequencies.