integrating sub xover

[thedman]

I'm planning a sub (or a pair of subs) for my first diy project

I currently have non-biwiraeble 2 way speakers with the xover at 2.9kHz.

If I use a 2 way passive sub xover, say, at 100 Hz, how will this interact with the xover already in my main speaker? Is it simply that the sub xover will split the signal at 100Hz and then the high pass signal from this xover will then be split at 2.9kHz by the xover in my main speaker. Or does something go wrong when you use 2 different xovers?

Thanks for any advice

[Cal Weldon]

Hi thedman,

Have you considered going active with the woofer? That way you get an amp and a variable XO in the same package and it costs only a little more than those huge coils you have to buy for a passive XO.

If you use the high level inputs to the plate amp, you will have a passive XO built in for your main speakers.

EDIT: Spelling

[richie00boy]

It won't affect the main crossover. But it will be rubbish for various reasons. Try and get a plate amp as Cal said.

[thedman]

Thanks for the advice, guys

I'll look into a plate amp as an alternative - any ideas where I should start?

Also, just for my own interest a a beginner, can you advise a bit more on why it would be so rubbish?

[tinitus]

http://www.reckhorn.com/index.php?ln=de&prod=a400

It has some nice functions that many others dont have, just a suggestion
Generally I would say that subs are crossed below 50hz and a monosub is then a possibility ... crossed 100hz+ it is a 3way and double woofers is a must, and they may not even have subbass qualities any more ... at 100hz+ you will need a highpass filter on main speakers too

Which to prefer depends on the rest of your setup

Why not passive? to cross 100hz or below you would need monster trafos around 20mH or more and to make even a simple 12db filter also som hefty caps ... its not cheap, allthough possible, but very tricky to get db level just right

[Colin]

Closer to home, you could try BK Electronics. In addition to the plate amps, they make a range of subs, so you can see how the amps are used. They enable you to take a signal to the sub either from the preamp output or direct from the speaker feeds to your main speakers. I have one of their subs and the system works well.