i give up

[theChris]

this is the 5th time that i've attempted to build a crossover for some speakers and test it out in my car. basically, i've got a 4channel amplifer. i found the +-12V rails and ground that the amp uses for the built in signal processing. so i built the crossover.

now my question is: i built for the input stage a differance amplifer. i guess they don't work well? in any case, for the left lowpass i have no signal. right lowpass gives a warbling kinda signal. so in any case, i've spent more than i wanted to already, and wasted more time than i wanted to. i'm probably just gonna wait 2 more months so i can get a PCB printed at school.

i have no testing equipment beyond a cheap DMM. i can't really test anything. it doens't explode, so i figure the caps are hooked up right.

[Netlist]

Don't give up!
Think of Africa. People have no money, no tools and build the nicest things with almost nothing.
I've never been there, but even in their biggest misery, you can see those people smile.
So don't give up, post us a schematic and/or some pictures. I’m sure you will fix it.
Go to sleep, and start with a fresh mind in the morning.

And don't blow up that DMM!

/Hugo

[theChris]

ok, well i found some things touching and a loose wire. that fixed it. it's broke now... i tested 2 speakers, the mid and the tweeter. on the left side: midrange output worked, but doesn't anymore. on the right side midrange output doens't work, but rather makes a slow ~5hz wave, i didnt realize until i got back there and saw it slowly moving.

the fact that the left side did work and no longer does disturbes me.

i know the following: the mid sounds kinda bad even with the filter, so i think the mids (which are 6.5" big) should probably be used for woofers only. i may just do that, use them in some other design.

but the left played mids and the right played highes. so the input buffer had to have worked at one time.

[theChris]

OK, that's it, i really give up now. i fixed the crossover. both the high and lowpass sections work perfectly. so why give up? MY AMP GAVE UP!!! i have a 4channel amp. now 1 of the channles (or maby 2, i didn't test all...) is bad. it makes an interesting static noise and the speaker just kinda gets sucked slowly down... or inward i guess. or outward if i wire it us differenetly...

in any case i got the thing to work, hooray, but the thing still doesn't work... boo...

[Netlist]

Originally posted by theChris
it makes an interesting static noise and the speaker just kinda gets sucked slowly down... or inward i guess. or outward if i wire it us differenetly...

in any case i got the thing to work, hooray, but the thing still doesn't work... boo...

This smells like DC or close to. Very bad for the speakers. It is easily measurable even with a cheap DMM.

Looks like you'll have to fix your amp first. Maybe this link could help you too:
http://www.eatel.net/~amptech/elecdisc/caraudio.htm

/Hugo