2-way active setup, digital crossovers

**skarsol** · 06-10-2005, 02:05 PM

Notice: I'm a computer guy, not a car guy or an audio guy. Also, try to avoid "thats way overkill!" responses please, this is more of a "lets see what can be done" project than a practical one.

My current setup is running linux on an athlon mobile. (car has 1 speaker in it at the moment, so none of this is actually installed in the vehicle yet). I'm running stereo signal from the CD drive of the computer into JACK which passes it through jack-rack then SuperCollider (effects processors) then into BruteFIR which splits it into 5 channels (and applies DRC eventually once I get it in the car). The 5 channels are left (high, mid), right (high, mid), and sub. These patch (unbalanced RCA) directly into their respective amps which then feed the components in the front (no xover) and the sub. I've got a master volume control script as well as a 32 band graphic EQ on each channel.

My biggest question would be where the best place for EQ would be. Would there be any advantage in EQing pre-bruteFIR vs post? Post requires more EQs (5 vs 2) but thats not really an issue. Anyone with a complete system wish that their EQ was after/before their crossovers? I'm also considering putting a parametric EQ on the 2 channels pre-xover then the 32 band after the xover to correct any small problems. Worthwhile or pointless?

Is there anything I'm missing? Something important I've overlooked in the signal chain?

Picture of the JACK connections
Picture of the graphic EQ

Thoughts? Questions? Comments?

**yak8998** · 06-11-2005, 10:43 AM

I'm running an alpine h700, so I don't think its overkill at all

I'd just run it before (2ch), seeing as running it after would be useless to a certain degree (unless your heavily overlapping your tweet/mid crossover). Say you cross your componets at 6khz. Your bands up to 6khz will effect the mids almost entirely, and the bands above will only effect the tweeters. Thus why you shouldn't bother running it after. You'll save a lot of CPU cycles this way as well I would think.

PS i'm a car audio guy

**skarsol** · 06-11-2005, 11:32 AM

Running it after wouldn't really consume any extra cpu cycles as the EQ is a pretty cheap operation and it would be easy enough to only provide the bands of interest graphically (ie: only give sliders for say 4K and up). But I can't really think of any compelling reason to do it after the crossover so unless someone comes up with one I'll prolly do it the simpler way.