Speaker-level Crossover?

Posted by: snoopstah

Speaker-level Crossover? - 23/08/2002 11:17

Hi,

You might have noticed my other post, regarding Mac Audio powered subs. This is related.

My current system is the empeg (of course) running through a JVC HU (bought 2 weeks before the firesale, so I couldn't justify buying an amp too). The JVC is running decent front and rear speakers from its internal amp. I'd like more bass, but I can't afford to amp the front/rear speakers currently.

If I get a sub, then obviously I'd like to cut everything below 80hz (ish) from going to the door speakers (they're components, and can't really handle low frequencies at any volume). However, going through the HU, it's not a simple case of twiddling a dial on an external amp or fitting crossovers in the line-level output stage.

Now my component speakers come with speaker-level crossovers already (to send the appropriate frequencies to the tweeters). So this must be possible. But has anyone seen anything that can cut frequencies on speaker-level outputs?

Many thanks,

A.
Posted by: dodgecowboy

Re: Speaker-level Crossover? - 23/08/2002 13:14

you can buy inline crossovers, some are called just that, and then some were called bass blockers, Im not sure where you can get them anymore crutchfield used to carry them.
Posted by: munkworks

Re: Speaker-level Crossover? - 26/08/2002 22:17

All you need is a bi-polar capacitor in series with each of your speakers. Assuming roughly a 4 ohm impedance (although at 80 to 100 hz. you are not too far away from speaker resonance), your value for the capacitor would be approx. 450 microfarad. Like I mentioned though, being this close to speaker resonance, I would personally cut that value in half. Buy two 225 microfarad caps or three 150 microfarad caps and put them in parallel to achieve 450 microfarad. That way you can peel some back if you wish to lower your value (raise the crossover point) to protect the speaker. Keep in mind this is a simple 1st order (6 db per octave) filter and therefore has limited protection capacity due to its gentle rolloff slope. Use your ears. They are some of your best tools when choosing a ballance between sound pressure and sound quality.
Posted by: Heather

Re: Speaker-level Crossover? - 28/08/2002 00:35

Like this one?
Posted by: munkworks

Re: Speaker-level Crossover? - 28/08/2002 08:13

Like these shown here: http://www.speakercity.com/xover/capacitors.shtml