Faulty sub amp on monolith 12?

J

JRED 1219

Audioholic
Anyone know what this sound might mean? I have the same issue as the guy in this video. If I unplug the sub, it will go away. Then power on and nothing. As soon as it gets some sort of signal and "warms up" for a while, this sound can be heard:


Bran spanking new monolith 12"
 
S

shadyJ

Speaker of the House
Have you tried swapping the outputs? Are you using a Y-splitter to feed both subs a signal or does the AVR have dual sub outputs? Have you tried different signal source aside from the AVR?
 
J

JRED 1219

Audioholic
Have you tried swapping the outputs? Are you using a Y-splitter to feed both subs a signal or does the AVR have dual sub outputs? Have you tried different signal source aside from the AVR?
Only the one sub.
No splitter.
Same cable, source and outlet as my previous klipsch sub that did not have this issue.
AVR does have dual outs - could try using the other one.
Will try a different source tomorrow.

Not sure what you mean by "swapping the outputs".
 
S

shadyJ

Speaker of the House
Only the one sub.
No splitter.
Same cable, source and outlet as my previous klipsch sub that did not have this issue.
AVR does have dual outs - could try using the other one.
Will try a different source tomorrow.

Not sure what you mean by "swapping the outputs".
By swapping the outputs, I mean switching the cables ends and plugging them into the other opposite subs.
 
AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
If the sub is new and already has a faulty amp as TLS thinks, might consider using passive subs and using your own amps.

A friend of mine had a big SVS flagship sub, so it wasn't cheap. He had to replace 2 sub amps. Now I hooked him up with passive subs.
 
J

JRED 1219

Audioholic
By swapping the outputs, I mean switching the cables ends and plugging them into the other opposite subs.
Tried different cable, different sub outs, different inputs on sub, switched cable ends. Still happens.

Likely a faulty amp I am thinking.

FUN!
 
J

JRED 1219

Audioholic
Anyone know what amp is used? I assume the DSP is tailored to this sub... Do getting a replacement amp would be difficult I would think.

It is under warranty, but what a pain to ship this back... from Canada! Monoprice will not send a new amp, as I have read on other forums.
 
lovinthehd

lovinthehd

Seriously, I have no life.
Anyone know what amp is used? I assume the DSP is tailored to this sub... Do getting a replacement amp would be difficult I would think.

It is under warranty, but what a pain to ship this back... from Canada! Monoprice will not send a new amp, as I have read on other forums.
Can you elaborate on Monoprice refusing to swap out amps?
 
J

JRED 1219

Audioholic
I'll try to call them and see, but from what I've read if the amp goes in the sub, they require you ship the entire unit back for replacement. They do not let you replace the amp yourself.
 
lovinthehd

lovinthehd

Seriously, I have no life.
I'll try to call them and see, but from what I've read if the amp goes in the sub, they require you ship the entire unit back for replacement. They do not let you replace the amp yourself.
Worth a try, can't imagine why they'd require that but....
 
TLS Guy

TLS Guy

Audioholic Slumlord
There is a post on AVS from I think the owner. I think the problem is they don't keep spare parts, including amps. So the clowns import the junk from China and must toss the returns. This chap posted about a year ago and said they were thinking of stocking replacement amps. He seemed to think that this would require monumental organization. So far nothing has apparently changed. You really do wonder how some of these executive types find their way out of bed in the morning. Come to that it might be better for all concerned if they didn't.

Seems these are problem units anyway, with lousy customer service.

The sub is ported, so all this DSP nonsense has to be pretty much bogus. There is not much you can do to EQ a ported sub. It will work just as well without DSP if it truly has it.

So my advice to the OP is not to ship it back unless he has stock in the shipping companies. I personally would put a nice set of terminals on the sub and get a nice solid amp, drive it with that and be done with it. Otherwise there is a good chance he will be shipping back a second or third time.

A Crown or QSC amp should fit the bill just fine. My best advice is to drop that sub amp like hot potato.
 
J

JRED 1219

Audioholic
Monoprice is paying return shipping across the border and DHL is picking it up from my house tomorrow. Customer service was great on the phone. Didn't ask too many questions, just a few diagnostic questions. Still a pain, but with the 5 year warranty and super fast customer service turnaround is comforting.
 
TLS Guy

TLS Guy

Audioholic Slumlord
Monoprice is paying return shipping across the border and DHL is picking it up from my house tomorrow. Customer service was great on the phone. Didn't ask too many questions, just a few diagnostic questions. Still a pain, but with the 5 year warranty and super fast customer service turnaround is comforting.
That is good, but they are still idiots. Some bean counter has told them NOT to invest capital in spare parts. This whole episode shows an extreme lack of common sense causing hardship to customers and themselves and is absolutely daft.
 
J

JRED 1219

Audioholic
That is good, but they are still idiots. Some bean counter has told them NOT to invest capital in spare parts. This whole episode shows an extreme lack of common sense causing hardship to customers and themselves and is absolutely daft.
Yes... Would very much prefer just to swap out the amp...
 
TLS Guy

TLS Guy

Audioholic Slumlord
Just for my future information, if I don't want to send the whole sub back, would this be a similar enough replacement amp?

If you can fit it without causing and air leak it should be fine. However those sub class D plate amps are just notorious for failures. I would use a decent externally installed amp personally. I'm glad I own nothing with one of those plate amps.
 
S

shadyJ

Speaker of the House
Just for my future information, if I don't want to send the whole sub back, would this be a similar enough replacement amp?

If that plate amp fits the cut out for the previous amp, yes, it should work. You will have to set the high pass filter to protect the driver below port tuning though. You could always just seal the cut out with a board with some binding posts on it, and just use an outboard amp too.
 
AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
There is a post on AVS from I think the owner. I think the problem is they don't keep spare parts, including amps. So the clowns import the junk from China and must toss the returns. This chap posted about a year ago and said they were thinking of stocking replacement amps. He seemed to think that this would require monumental organization. So far nothing has apparently changed. You really do wonder how some of these executive types find their way out of bed in the morning. Come to that it might be better for all concerned if they didn't.

Seems these are problem units anyway, with lousy customer service.

The sub is ported, so all this DSP nonsense has to be pretty much bogus. There is not much you can do to EQ a ported sub. It will work just as well without DSP if it truly has it.

So my advice to the OP is not to ship it back unless he has stock in the shipping companies. I personally would put a nice set of terminals on the sub and get a nice solid amp, drive it with that and be done with it. Otherwise there is a good chance he will be shipping back a second or third time.

A Crown or QSC amp should fit the bill just fine. My best advice is to drop that sub amp like hot potato.
It would be good if he could turn his "active sub" with a bad amp into a "passive sub" so he can use his own External Amps.

This is exactly the reason I hate the idea of putting amps inside subs and speakers, especially if the speakers/subs weigh so much. Shipping becomes a problem. Another problem is if these companies don't have spare parts, especially a few years later.

So it's best to keep Amps OUTSIDE the components.
 

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