I have just bought another set of Jamo speakers off the internet only to discover...
Jamo Classic 8 3 ways
The dual low range drivers are not doing anything. I pulled them out and connected them direct to the amp and they both still work. The crossover has no obvious bad connections or damaged caps. I hooked one back up, connected the speaker and poked the crossover a bit with the rubber handle of a screwdriver to see if there was any life but nothing.
Just a note, I have never dealt with speakers designed for bi amp/bi wiring and one of the speakers has missing jumpers so I just stripped the wire back a couple of inches and attached it across the terminals. Can't see how this would have caused the problem and it worked fine on the opposite channel but just checking...
May have found some second hand crossovers on ebay.
Jamo speakers they always look so pretty in the pictures but...will I ever learn?
Any advice humbly accepted.
Jamo Classic 8 3 ways
The dual low range drivers are not doing anything. I pulled them out and connected them direct to the amp and they both still work. The crossover has no obvious bad connections or damaged caps. I hooked one back up, connected the speaker and poked the crossover a bit with the rubber handle of a screwdriver to see if there was any life but nothing.
Just a note, I have never dealt with speakers designed for bi amp/bi wiring and one of the speakers has missing jumpers so I just stripped the wire back a couple of inches and attached it across the terminals. Can't see how this would have caused the problem and it worked fine on the opposite channel but just checking...
May have found some second hand crossovers on ebay.
Jamo speakers they always look so pretty in the pictures but...will I ever learn?
Any advice humbly accepted.
All bi-amped speakers need either two amplifiers or jumpers fitting between the two pairs of terminals for the speakers to work.
If you only connect one amplifier to the bottom terminals only the bass end of the speaker will work. If you connect the wires only to the top pair only the tweeter end of the speaker will work.
If you only connect one amplifier to the bottom terminals only the bass end of the speaker will work. If you connect the wires only to the top pair only the tweeter end of the speaker will work.
K&D, I can be a bit obtuse in my descriptions sometimes. I stripped the speaker cables back a couple of inches and bridged them across the top and bottom terminals and thereby used the cable as a jumper. It is working fine on the other channel and in the testing I have done I have connected the upper and lower terminals separately and together and in every configuration upper range works and lower range does not.
Cheers
Cheers
You may have a circuit breaker in the crossover. Or if a fuse, the contacts may not be conducting even if the fuse is intact. Jamo it!
photos
Here are the crossovers. Particle board...Classy stuff.
something is keeping the mid driver in its enclosure, I can get it loose but it won't come out more than a couple of millimetres. At first I thought it was the speaker wires where they run into the mids internal enclosure but it seems to be something else. I guess I'll have to work on the crossovers from this position.
Here are the crossovers. Particle board...Classy stuff.
something is keeping the mid driver in its enclosure, I can get it loose but it won't come out more than a couple of millimetres. At first I thought it was the speaker wires where they run into the mids internal enclosure but it seems to be something else. I guess I'll have to work on the crossovers from this position.
The bassdriver has a standard second order lowpass filter consituting of a serial iron core coil and then a 72µF cap across + and -, standard stuff. I would expect the cap having developed a short. Try desolder one of the ends of the caps and listen if sound returns?
The other option is that the coil has gone open, this is even less complicated to test. Use some crocodile cables as jumpers past the coil and listen for sound returning
The other option is that the coil has gone open, this is even less complicated to test. Use some crocodile cables as jumpers past the coil and listen for sound returning
Thank you Doctor. I'll get onto it. When you say desolder the cap, do you mean I should remove the solder and then resolder it back in or test it with one end of the cap removed so it is out of the circuit?
Desolder one end of the cap and disconnect it from the circuit.
You do have a valid point though, do check carefully for dry joints, resweating all of them wouldn't be a bad idea.
Let us not colour this thread with opinions about the OPs speakers, he's trying to get his working.
Xover
Was looking for this...(had to search again).
X-over Classic 8 (found on other forum)
Arne K
(they sure LOOK good for the typical used-price = less than £ 100)
Was looking for this...(had to search again).
X-over Classic 8 (found on other forum)
Arne K
(they sure LOOK good for the typical used-price = less than £ 100)
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As has already been discussed either the 4.0mH coil is open circuit, the 72uF cap is short circuit or you have a bad connection. The coil is easy to test, just remove the cap for testing.
After all that... I was testing with the jumper cable and they started crackling in and out and I found the problem. The spades connectors on the cabinet side of the terminals had become so corroded that they weren't conducting. I've put everything back together with the speaker wires running straight in through the bass port and they are sounding perfect. Get some new terminals tomorrow. Many thanks to all for your time.
That's one set of Jamo down one to go...
That's one set of Jamo down one to go...
"or you have a bad connection."
Hadn't read that when I posted... Well spotted Katie and dad.
And Cobra... From what I heard so far they are certainly sound clean but I think their days are numbered here too, I need to stop trying to put ported floor standers in my tiny apartment. Though I've got a feeling they are gonna sound better up on the bench... They'll certainly look great up there.
Hadn't read that when I posted... Well spotted Katie and dad.
And Cobra... From what I heard so far they are certainly sound clean but I think their days are numbered here too, I need to stop trying to put ported floor standers in my tiny apartment. Though I've got a feeling they are gonna sound better up on the bench... They'll certainly look great up there.
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