Tweeter not working?

[Michaelholder1]

Ok so i stupidly agreed to leand out my B&W Dm602 s3s out to my friend for her 21st birthday and I got them back today and one of the tweeters isnt working. Its not been pushed in and I opened it up to see if any connections had come loose but everything was in place; so im just wondering what might have caused the tweeter to have stopped working? Is it likely im going to have to replace the whole tweeter? I presume that would cost about £50 if I ordered one from B&W?

 

[Overdose]

Ok so i stupidly agreed to leand out my B&W Dm602 s3s out to my friend for her 21st birthday and I got them back today and one of the tweeters isnt working. Its not been pushed in and I opened it up to see if any connections had come loose but everything was in place; so im just wondering what might have caused the tweeter to have stopped working? Is it likely im going to have to replace the whole tweeter? I presume that would cost about £50 if I ordered one from B&W?

Spares at the link below.

http://www.technosound.co.uk/eShop/ssBW.html

 

[Ketan Bharadia]

Yes, it sounds like you need a new tweeter.

 

[altruistic.lemon]

You should really check the crossover first to make sure all is well with the high pass components.

 

[Michaelholder1]

I was thnking that, but how would i be able to tell if the cross over was fine? Would something obvious be wrong with the cross over when i had a look?

 

[altruistic.lemon]

Test the resistance of the tweeter with a multimeter. Should be between 4 and 8 ohms, but if it is 0, it is shot.

 

[andyjm]

Test the resistance of the tweeter with a multimeter. Should be between 4 and 8 ohms, but if it is 0, it is shot.

If the tweeter was overdriven, it has most likely fried the voicecoil. This will fail to open circuit and the multimeter will read infinity (or whatever symbol it uses for open circuit), not 0 ohms which would indicate a dead short.

 

[Overdose]

I was thnking that, but how would i be able to tell if the cross over was fine? Would something obvious be wrong with the cross over when i had a look?

I suspect that the voice coil has blown due to excessive power pushed throught it. If you use a multi-meter to check the resistance across the coil, it will most likely read O/L as the wire will have burnt like a fuse at some point in the coil creating an open circuit.

If the resistance check returns as within spec (ask the spares supplier or B&W what this should be), then the fault lies elsewhere.

 

[eggontoast]

As said above check the impedance of the voice coil or even better; tell the misses they are completely shot and treat yourself to a new pair of speakers

 

[altruistic.lemon]

If the tweeter was overdriven, it has most likely fried the voicecoil. This will fail to open circuit and the multimeter will read infinity (or whatever symbol it uses for open circuit), not 0 ohms which would indicate a dead short.

Yes, correct, but will still be outside the 4 - 8 ohm range, depending on the original speaker specs, but the majority of drivers are within this range.

 

[Overdose]

If the tweeter was overdriven, it has most likely fried the voicecoil. This will fail to open circuit and the multimeter will read infinity (or whatever symbol it uses for open circuit), not 0 ohms which would indicate a dead short.

Yes, correct, but will still be outside the 4 - 8 ohm range, depending on the original speaker specs, but the majority of drivers are within this range.

Your range for checking resistance is arbitrary, the OP needs the specification from the supplier to determine serviceability. A simple cross check of the other known good tweeter would be a reasonable comparison.

 

[harrisonp]

I would guess duff tweeter. Why not just swap it over with the known good one to prove it as you say only one has gone.

I once sent for one and paid about £35.00, the speech coil went open circuit -a common fault on these tweeiers. I have heard that B&W wont supply spares anymore but not sure if that is the case?

Regards,

PJH

 

[altruistic.lemon]

Your range for checking resistance is arbitrary, the OP needs the specification from the supplier to determine serviceability. A simple cross check of the other known good tweeter would be a reasonable comparison.

Not at all. If you check driver specs on any manufacturer websites you'll see most fall within the 4 - 8 ohm spectrum, I would have thought you of all people would have known that. Also, if a reading is ~ or 0, surely that indicates a problem no matter what the impedance is..

Yes, checking the other tweeter would be another way, assuming it continues to perform on spec.

 

[Overdose]

Your range for checking resistance is arbitrary, the OP needs the specification from the supplier to determine serviceability. A simple cross check of the other known good tweeter would be a reasonable comparison.

Not at all. If you check driver specs on any manufacturer websites you'll see most fall within the 4 - 8 ohm spectrum, I would have thought you of all people would have known that. Also, if a reading is ~ or 0, surely that indicates a problem no matter what the impedance is..

Yes, checking the other tweeter would be another way, assuming it continues to perform on spec.

Typical specifications given on manufacturers details are across the speaker terminals and are for total impedence of whatever circuitry is inside the box, not usually for each individual driver, as this is largely irrelevent to the buyer.

 

[MajorFubar]

Stick the other tweeter in.
Or stick the suspected-broken tweeter in the other speaker.

 

[Overdose]

Stick the other tweeter in. Or stick the suspected-broken tweeter in the other speaker.

And possibly cause a failure there too?

 

[MajorFubar]

Stick the other tweeter in. Or stick the suspected-broken tweeter in the other speaker.

And possibly cause a failure there too?

If all he's getting is silence then it's more likely that either the voice-coil in the tweeter or part of the speaker's x-over has gone open-circuit, not closed circuit. So he'd have to be very unlucky to blow something with a simple swap-out of either the known-good tweeter into the 'silent' speaker, or the suspected-faulty tweeter into the known-good speaker..

 

[altruistic.lemon]

Typical specifications given on manufacturers details are across the speaker terminals and are for total impedence of whatever circuitry is inside the box, not usually for each individual driver, as this is largely irrelevent to the buyer.

So, so wrong. Have a look at http://seas.no/index.php or http://www.scan-speak.dk/ . Remember the subject concerns individual drivers, as did all responses, except, perhaps, yours.

 

[harrisonp]

I only have a basic electronics knowledge but i don't see how you would damage the exchange tweeter buy swapping it over.

The crossover only handles signals.

If one of the crossover resistors was burnt out making it open circuit then no signal would get to damage the drivers including the tweeter and if one of the crossver capacitors had gone short circuit your amps output protection would shut the amp down, faint heart.

PJH

 

[Michaelholder1]

Well i dont have a multimeter so I wont be able to check that anyway but swapping the tweeters over seems like a good idea, lets just i hope to dont **** up the other speaker! aha

 

[Michaelholder1]

Ok so I left the tweeter on my bed for an extended period of time after i took it out. Over a night as I wasnt in and there is a reddy brown circular mark where it was sat, is this anything to do with a voice coil frying? Also if this was the case would i just need to replace the diaphragm as all the electronics seem to be in that bit as the rest just seems like a magnet with a bit sticking out the end stuffed with a wooly material?

 

[matt49]

Ok so I left the tweeter on my bed for an extended period of time after i took it out.

Cue dirty jokes.

 

[Andrew Everard]

Ok so I left the tweeter on my bed for an extended period of time after i took it out. Over a night as I wasnt in and there is a reddy brown circular mark where it was sat, is this anything to do with a voice coil frying?

Sounds like ferrofluid, used for cooling in tweeters, leaking out. Think that's a pretty sure sign the tweeter is shot.

 

[Michaelholder1]

Ok so i swapped over the tweeters and the other one worked in the other cab so its definitely the tweeter gone. Now i've contacted B&W about replacing some 603 s2 diaphragms and need to ring them up to get that sorted so i'll just order the new tweeter with them. But do i need to replace the whole tweeter or just the diaphragm? As far as I'm aware the diaphragm is where all the electronics looking at the my 603 s2 diaphragms now. The rest of the tweeter just seems to be the magnet and enclosure right? Anyone know?

 

[Andrew Everard]

I think you'd do best to replace the entire tweeter assembly.