Hello,
New to this site. I just put together a new system. I have (2) Carver M1.0t with the mkII opt002 upgrade monoblock amps and a Carver C-1 preamp hooked up to a pair of B&W 801 Matrix speakers. They were playing great until I cranked them up a bit. I saw smoke coming from the portholes of both speakers. I turned the volume completely down and let the smoke clear out. Now the mid-range and tweeter are not functioning at all. I assume I smoked the crossovers.
Any suggestions on direction to getting these repaired or parts for the crossovers? Any upgrades I should be looking into?
Thanks for any help you can provide. Happy Thanksgiving!
Trip
New to this site. I just put together a new system. I have (2) Carver M1.0t with the mkII opt002 upgrade monoblock amps and a Carver C-1 preamp hooked up to a pair of B&W 801 Matrix speakers. They were playing great until I cranked them up a bit. I saw smoke coming from the portholes of both speakers. I turned the volume completely down and let the smoke clear out. Now the mid-range and tweeter are not functioning at all. I assume I smoked the crossovers.
Any suggestions on direction to getting these repaired or parts for the crossovers? Any upgrades I should be looking into?
Thanks for any help you can provide. Happy Thanksgiving!
Trip
The likely culprits are resistors in series with the tweeter and midrange, blowing them cause open circuits and thus no sound.
Remove the bassdriver
Locate the crossover, if covered with foam even some few watts can make the components really hot.
Look for burn marks at the board and components (and covering insulation).
If in US Parts-Express non inductive 12W resistors should do the trick. If you need more power simply put several in parallell.
Make sure that the new resistors are placed in such a way that they can dissapate the heat
Remove the bassdriver
Locate the crossover, if covered with foam even some few watts can make the components really hot.
Look for burn marks at the board and components (and covering insulation).
If in US Parts-Express non inductive 12W resistors should do the trick. If you need more power simply put several in parallell.
Make sure that the new resistors are placed in such a way that they can dissapate the heat
Please,send photo crossovers.I still don't understand how you could have destroyed the crossover.
B&W service manuals can be downloaded from here: B&W Group North America Service & Support - Service Manuals
The 801 Matrix has a more complex crossover than usual with protection circuit. So lots of components that can go wrong, and likely what is broken is part of the protection circuit, maybe simply the relays.
You need to either send the speakers to a reputable repair shop, or remove yourself the crossover and inspect it searching at least burning signs. Post photo.
Ralf
The 801 Matrix has a more complex crossover than usual with protection circuit. So lots of components that can go wrong, and likely what is broken is part of the protection circuit, maybe simply the relays.
You need to either send the speakers to a reputable repair shop, or remove yourself the crossover and inspect it searching at least burning signs. Post photo.
Ralf
The crossover of matrix series is located at the retractable bottom panel. So no woofer unmounting is needed (you only stumble upon the matrix…).
Perhaps the drive units are what smoked, possibly due to instability (HF oscillation) in the amp.
Have you checked continuity of the drivers?
Can you smell burn if you stick your nose into the coil area of the drivers?
Have you checked continuity of the drivers?
Can you smell burn if you stick your nose into the coil area of the drivers?
I did try to smell components with my nose but couldn't detect anything unusual. I have not checked any components as of yet.
Trip
Trip
A quick resistance check should locate the problem. You may need to unsolder one wire to each driver to isolate it from the crossover in order to get an accurate measurement.
The only driver that can smoke through the ports is the bass driver, as the mid range driver and tweeter have their own enclosures.
And, oh dear Trip, you just had to see how loud it would go!
I feel your pain!
Two protection circuits were incorporated in the Series 2 model, but not in the Series 3.
Which Series is yours?
Smoke out of the port.
XO in the base, mid/top in a different volume.
The only potential source of smoke is the driver. I have had XO resistors get so hot thatthey start the foam damping on fire, but it is very unlikely the driver could do that.
A VERY high probability that you have smoked th ebass driver.
An XO you can fix. A new woofer is a lot harder.
dave
XO in the base, mid/top in a different volume.
The only potential source of smoke is the driver. I have had XO resistors get so hot thatthey start the foam damping on fire, but it is very unlikely the driver could do that.
A VERY high probability that you have smoked th ebass driver.
An XO you can fix. A new woofer is a lot harder.
dave
The mid and tweeter ain't functioning, Dave - protection circuits?
But at least the woofer is still working, apparently!
But at least the woofer is still working, apparently!
Hi Dave,
Thanks for the replies. The only sound coming from the speaker after the smoke billowed out of the speaker lower port was through the woofer. The midrange and tweeter on the top of the cabinet were dead. I am really new at this stuff so I apologize if I sound ignorant but I am.
Is it possible for this smoke to have traveled from the tweeter/midrange enclosure on top of the main cabinet through the attachment nipple and into the main enclosure?
Would a problem with the LF driver cause a problem with the MF and HF speakers?
Thanks for the replies. The only sound coming from the speaker after the smoke billowed out of the speaker lower port was through the woofer. The midrange and tweeter on the top of the cabinet were dead. I am really new at this stuff so I apologize if I sound ignorant but I am.
Is it possible for this smoke to have traveled from the tweeter/midrange enclosure on top of the main cabinet through the attachment nipple and into the main enclosure?
Would a problem with the LF driver cause a problem with the MF and HF speakers?
Think Kaos is right. Smoke from the parallel cap (C5) in the woofer and the series cap (C3) in the midrange circuit. What is more, a previous owner seems to have removed the protection circuit boards (the empty spaces on the ground panel speak for themselves). If the tweeter doesn’t function anymore, I fear that one is gone, but likely the woofer and midrange could have survived the torture experiment. They have to be checked though.