Hello. Not sure this is the right category to place this thread, but here goes..
Some time ago I managed to blow a component on one of the crossovers (I figure this is what I did..) for my Cerwin Vega CLS-12.
Now the sub in the speaker plays full tone, or at least some highs. The tweeter is lower than usual, but the mid-speaker plays just fine. When I turn up the amp, the amp goes in Safe mode and turns off, so obv the impedance has changed as well.
I've replaced the biggest and smallest capacitors on the crossover, but hasn't helped a bit. The biggest cap buldged a bit, but it had always done that, so I figured that might be the problem and replaced it. Didn't help, so I got my hands on a tool to measure caps (no idea what it's called in english - nor danish really) and measured the caps. The smallest cap (12uF) seemed to be broke, so I ordered a new and replaced it as well.
None of this helped on the issue. So I have no idea what could be the problem now..
Hope someone here have an idea! I don't have much knowledge on this subject..
Thanks in advance!
/SpiXe
Some time ago I managed to blow a component on one of the crossovers (I figure this is what I did..) for my Cerwin Vega CLS-12.
Now the sub in the speaker plays full tone, or at least some highs. The tweeter is lower than usual, but the mid-speaker plays just fine. When I turn up the amp, the amp goes in Safe mode and turns off, so obv the impedance has changed as well.
I've replaced the biggest and smallest capacitors on the crossover, but hasn't helped a bit. The biggest cap buldged a bit, but it had always done that, so I figured that might be the problem and replaced it. Didn't help, so I got my hands on a tool to measure caps (no idea what it's called in english - nor danish really) and measured the caps. The smallest cap (12uF) seemed to be broke, so I ordered a new and replaced it as well.
None of this helped on the issue. So I have no idea what could be the problem now..
Hope someone here have an idea! I don't have much knowledge on this subject..
Thanks in advance!
/SpiXe
It sounds like a short somewhere, either in a crossover component or driver. The tool you have is probably an LCR (inductance / capacitance / impedance) meter. You should be able to measure all the parts on the crossover. I'd measure them against the parts in the working speaker / crossover.
Are you able to grab a picture of the crossover boards? Do any of the drivers or crossover components look or smell burned?
Are you able to grab a picture of the crossover boards? Do any of the drivers or crossover components look or smell burned?
+1. I agree. Inductor coils can hide shorts internally in the windings. You can only find them by measurements with an LCR meter. If you do it, be sure to disconnect at least one of the coil leads first.
Pretty sure the -woofer- worked just fine, when I connected it to the other speaker's board. Gonna do that again. Assuming it's not the driver, therefor.
mjf - How would I compare them? All components look(ed), except for the cap I replaced already. There's a little bit of brown-ish substance on one of the resistors (I think it is), but I figured it was glue or something. It doesn't smell burned. I'm gonna take some pictures of it, when I get back home (not near the speakers atm).
mjf - How would I compare them? All components look(ed), except for the cap I replaced already. There's a little bit of brown-ish substance on one of the resistors (I think it is), but I figured it was glue or something. It doesn't smell burned. I'm gonna take some pictures of it, when I get back home (not near the speakers atm).
No idea what the coil is then, if it's not the voice coil they're talking about?
Here's a pic of the crossover board. Please don't mind my lousy placing of the small cap.. It's more or less temporary.
http://peecee.dk/uploads/122011/IMG_20111205_202352.jpg
The coil you were talking about is the red wire covered by the black tape with the white .. thingy around it, right? (Great English skills..) The ones there are four of?
http://peecee.dk/uploads/122011/IMG_20111205_202352.jpg
The coil you were talking about is the red wire covered by the black tape with the white .. thingy around it, right?
(Great English skills..) The ones there are four of?
Actually , I was talking about the voice coil
So , the replacement cap is obviously wrong : it seems to me a 'normal' electrolytic ( as you may see a plus and a minus polarity -only the minus...- on its legs ) instead of the non polarized used in such circuits - bipolar electrolytics
But that's not a drama as you can use regular non bipolar caps , just double the value and put them in series , in 'anti-phase' (+)--(+) or get 4 of the target value and do a phase and anti-phase serial-parallel connection .
It's very clear , right ???
If Speakerdoctor was referring to the coil deputed to do the lowpass of the woofer ...well , I haven't found the way till today to break one : much thermal overload due to excessive power may corrupt the insulation , but that happens with hours of ear-damaging levels .
Spixe , you should try to run the woofer without any filtering -you won't break it - to check if it is sane and working .
You can even remove the strip around the coil (s) and the black insulation to check if it's 'normal ' or 'burned' .
So , the replacement cap is obviously wrong : it seems to me a 'normal' electrolytic ( as you may see a plus and a minus polarity -only the minus...- on its legs ) instead of the non polarized used in such circuits - bipolar electrolytics
But that's not a drama as you can use regular non bipolar caps , just double the value and put them in series , in 'anti-phase' (+)--(+) or get 4 of the target value and do a phase and anti-phase serial-parallel connection .
It's very clear , right
???If Speakerdoctor was referring to the coil deputed to do the lowpass of the woofer ...well , I haven't found the way till today to break one : much thermal overload due to excessive power may corrupt the insulation , but that happens with hours of ear-damaging levels .
Spixe , you should try to run the woofer without any filtering -you won't break it - to check if it is sane and working .
You can even remove the strip around the coil (s) and the black insulation to check if it's 'normal ' or 'burned' .
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Now we're getting technical.. Haha. Well. I've replaced them with bipolar electrolytics caps, I should think? Neither the cap I removed nor replaced it with had polarities marked on them (as far as I was able to see)?
I'm not totally sure.. Are you saying it should be a polarized cap or a bipolar cap? The cap I've installed is a "12 uF 100V Bennic Bipolar B10", so pretty it's bipolar. But it was much smaller than the other cap, which I was wondering why.
I'm not totally sure.. Are you saying it should be a polarized cap or a bipolar cap? The cap I've installed is a "12 uF 100V Bennic Bipolar B10", so pretty it's bipolar. But it was much smaller than the other cap, which I was wondering why.
Ok , I was 'abducted to the wrong side' by its size , too.
I've fried some Indeed , I use 250 V poly caps from then to now , or
at least I can recognize the right type for its duty in the circuit .
So ,next step would be to apply the scientific path ; try the woofer alone , reverse components ( speakers ) between the two channels , make a reverse engineering of the circuit and try to draw it on paper : You'll find that it'll be a typical 3 way crossover
by its size , too.I've fried some
Indeed , I use 250 V poly caps from then to now , orat least I can recognize the right type for its duty in the circuit .
So ,next step would be to apply the scientific path ; try the woofer alone , reverse components ( speakers ) between the two channels , make a reverse engineering of the circuit and try to draw it on paper : You'll find that it'll be a typical 3 way crossover
Hm. I've tried the woofer alone, I've tried putting the woofer into the other cabinet with the other crossover, and it works fine. I've tried replacing the tweeter with a normal 4ohm speaker, and it still does it.
I'm pretty sure the crossover is the problem in the one speaker. But after replacing the biggest and smallest caps, I'm clueless. What other component on the board can cause the woofer to play highs and the highs to lack volume?
I'm pretty sure the crossover is the problem in the one speaker. But after replacing the biggest and smallest caps, I'm clueless. What other component on the board can cause the woofer to play highs and the highs to lack volume?
I just don't know .
The crossover acts as a splitter of the various frequency ranges ; every way ends with
the speaker's coil as the load , which should be 8 Ohm in Hi-fi .
Coils in series with the signal cut the treble , in parallel cut the bass ; same for capacitors ( and inverted !! ).
If only one channel has the problem , probably you had 'cooked' it , but you say that the speakers are allright . If the coils are cooked , they may act as a short circuit .
You should take off the Pcb the good ones and the suspect ones , and check with a DVM the resistance ...they should be under 1 Ω , and a short is 0
The crossover acts as a splitter of the various frequency ranges ; every way ends with
the speaker's coil as the load , which should be 8 Ohm in Hi-fi .
Coils in series with the signal cut the treble , in parallel cut the bass ; same for capacitors ( and inverted !! ).
If only one channel has the problem , probably you had 'cooked' it , but you say that the speakers are allright . If the coils are cooked , they may act as a short circuit .
You should take off the Pcb the good ones and the suspect ones , and check with a DVM the resistance ...they should be under 1 Ω , and a short is 0
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