Active crossover

[MaXiZ]

Hi to all.
Did someone tryed this?

I know it's from ESP.
I've just build it but no sound from it..
Maybe i'm doing something wrong as always..
How shoud i connect the speaker?
I mean the gnd should be connected to gnd of car stereo or the gnd from the output of car stereo were i connect the speaker??
And what's the right way to test it?
How i can check if the crossover is running correctly?
And is there a way to check if the Opamp are ok?

[HDTVman]

Originally posted by MaXiZ
Hi to all.
Did someone tryed this?

I know it's from ESP.
I've just build it but no sound from it..
Maybe i'm doing something wrong as always..
How shoud i connect the speaker?
I mean the gnd should be connected to gnd of car stereo or the gnd from the output of car stereo were i connect the speaker??
And what's the right way to test it?
How i can check if the crossover is running correctly?
And is there a way to check if the Opamp are ok?

MaXiZ this is a low level crossover. By reading your post is seems like you are tring to connect the speakers to the output of the crossover. You need to use an amplifer for each output of the crossover to drive the speakers. The input to the crossover would be low level also (RCA jack) not the speaker output of the stereo.

Good Luck BZ

[MaXiZ]

this is a low level crossover

What mean?
I'm a beginner...

like you are tring to connect the speakers to the output of the crossover

Exactly... The positive to the output of crossover and the negative at the negative of car stereo output...
Wrong right?

You need to use an amplifer for each output of the crossover to drive the speakers

And a preamp right???

The input to the crossover would be low level also (RCA jack) not the speaker output of the stereo.

What's the difference excuse me???
The input at the crossover should be the positive of car stereo speaker connection output right???
And is there a way to check if the xover is running correctly? Is a good idead to connect a +12V at the input for example? Just to see if there's a certain voltage output...?

[Vigier]

About the last part: DON'T connect the 12V at the input. The 1µF will probably block it, but if not, you can throw away your OpAmps, and I don't think you want that!

Grtz, Joris

[MaXiZ]

ok and could u explain me the other quesion? and ho to check if an opamp is ok?

[HDTVman]

quote:
this is a low level crossover

What mean?
I'm a beginner...

This means that the audio signal is at a low level, used to go from one audio component to another. Very little power at this point.


quote:
like you are tring to connect the speakers to the output of the crossover

Exactly... The positive to the output of crossover and the negative at the negative of car stereo output...
Wrong right?

Wrong!
The "positive" output of the high to the input of the tweeter amplifer, The "positive" output of the mid to the midrange amplifer and The "positive" output of the low to the input of the woofer amplifer. The negitive for each output is used for the shield connection of the cable used to take the signal to the amplifers.

quote:
You need to use an amplifer for each output of the crossover to drive the speakers

And a preamp right???

No. The crossover operates at the output of a preamp, or in the case of car stereo equipment, the RCA jacks found on the better equipment intended for use with an external high power amplifer.


quote:
The input to the crossover would be low level also (RCA jack) not the speaker output of the stereo.

What's the difference excuse me???

The amount of power present for starters. The input for this type of active low level crossover would only be .001 or .002 watts and the output power is about the same.


The input at the crossover should be the positive of car stereo speaker connection output right???

That would be true for a high level passive crossover, a big set of coils and caps, but that's not what you have. The crossover you have is intended to divide the tuner/ CD/ cassette output signal into 3 frequency ranges. These 3 signals then go to the input of amplifers which drive the speakers.


And is there a way to check if the xover is running correctly? Is a good idead to connect a +12V at the input for example? Just to see if there's a certain voltage output...?

To test the crossover you should use a signal generator or a small battery powered CD player as the input. The signal path could then be checked with an oscilliscope or the output connected to the input of any amplifer with a speaker connected to the amplifers output.

If this is not clear to you maybe you need to find someone local to you that can show you these things.

Later BZ

[MaXiZ]

Ok and can i explain me this...
Stereo=>Crossover=>High=>Amplifier=>Speaker (soung ok)
=>Mid=>Amplifier=>Speaker (soung baaaad)
=>Low=>Amplifier=>Speaker (soung ok)

With sound bad i mean that i ear what i should but i ear an heavy noise... And i don't mean a "gzzzzzzz" but something similar to "wiiiiiii" "beeeeeeeeeeeeeeeee".. I hope to get explain! ANyway i ear this only at the mid and not at the low/high..
I use a SMPS to supply the crossover (+/-15V)

[HDTVman]

I can only quess but I think that the opamp for the mid output may have failed. The noise you hear is the noise from the power supply because the opamp is shorted. But that is just a quess.

It could be an error in the wiring.

Later BZ

[5th element]

Yeah ive used active xovers before still do now infact and am making one, need the copper clad to arrive. Anyway. In my whole time making them I have had wiring problems and have neva killed amp opamp, however I was also using all the correct inputs and outputs. Anyway the only time I killed an op is wen I accidentaly put one the wrong wasy round in its IC socket, the whole thing got v hot and just died.

I have also had very odd and not nice noises from the circuits wen not wired rite, once the problem is sorted it all worked fine. No dead opamp, so there is still hope yet.

Hope you do get it sorted,

Cheers Matt

[DRC]

Ok and can i explain me this...
Stereo=>Crossover=>High=>Amplifier=>Speaker (soung ok)
=>Mid=>Amplifier=>Speaker (soung baaaad)
=>Low=>Amplifier=>Speaker (soung ok)

With sound bad i mean that i ear what i should but i ear an heavy noise... And i don't mean a "gzzzzzzz" but something similar to "wiiiiiii" "beeeeeeeeeeeeeeeee".. I hope to get explain! ANyway i ear this only at the mid and not at the low/high..
I use a SMPS to supply the crossover (+/-15V)

Check around the 2 opamps too the left of the MID out (no IC numbers !). From your description all others must be working. Did you build stereo ? Are both channels the same ?
Good luck, Dave