KEF Kube10

[Scotty19]

I have 2 KEF Kube 10 subwoofers hooked up to my Integra DRX 4.3 AV Receiver using the LFE connection. The sound is fine when I have one sub turned on and it doesn’t matter if it’s the one on the left or right. When both subs are on I get an occasional pop in the left sub. I thought it may have been a power issue so I am running the two main speakers through two Marantz mono blocks. Any advice would be appreciated.

 

[TLS Guy]

I have 2 KEF Kube 10 subwoofers hooked up to my Integra DRX 4.3 AV Receiver using the LFE connection. The sound is fine when I have one sub turned on and it doesn’t matter if it’s the one on the left or right. When both subs are on I get an occasional pop in the left sub. I thought it may have been a power issue so I am running the two main speakers through two Marantz mono blocks. Any advice would be appreciated.

How are the two subs connected, via Y-connector or each to the receiver?

 

[Scotty19]

How are the two subs connected, via Y-connector or each to the receiver?

There are two subwoofer ports on the back of the receiver so each one has its own connection

 

[lovinthehd]

Swap the subs around, any change?

 

[Scotty19]

No it seems to be the left side. I bought better cables but still the same. I have read that the popping may happen if the amp doesn’t have enough power. That’s why I run my mains through the mono blocks.

 

[lovinthehd]

No it seems to be the left side. I bought better cables but still the same. I have read that the popping may happen if the amp doesn’t have enough power. That’s why I run my mains through the mono blocks.

Don't know why the subs would make any sounds due the amplifier section of the avr lacking (altho overdriven could create issues I suppose). So is it the particular sub you have on the left or no matter what you do with cable swapping, the problem remains on the left sub?

 

[TLS Guy]

No it seems to be the left side. I bought better cables but still the same. I have read that the popping may happen if the amp doesn’t have enough power. That’s why I run my mains through the mono blocks.

You mean the left sub? Then you need to change the connections around, and see if the pop moves to the right side. If it stays on the left, then your left sub is faulty. If it moves then the problem is on the receiver output.

Power has nothing to do with this. A sub connection is a high impedance connection, and no appreciable power goes down a sub connection. Whoever told you that has his mouth on the wrong side of his neck.

My bet is that this fault is in the sub.

 

[Scotty19]

Yes only the left side which would lead you to think the issue is the receiver yet there’s no issue on the left side when only the one subwoofer is turned on

 

[lovinthehd]

Maybe just try a soft reset of the avr (unplug it for a bit)....that can often clear up strange glitches. Still, did you actually change cables or subs to eliminate a particular sub?

 

[TLS Guy]

You mean the left sub? Then you need to change the connections around, and see if the pop moves to the right side. If it stays on the left, then your left sub is faulty. If it moves then the problem is on the receiver output.

Power has nothing to do with this. A sub connection is a high impedance connection, and no appreciable power goes down a sub connection. Whoever told you that has his mouth on the wrong side of his neck.

My bet is that this fault is in the sub.

Yes only the left side which would lead you to think the issue is the receiver yet there’s no issue on the left side when only the one subwoofer is turned on

Switch the connectors on the back of the receiver and see what happens. This has to be a sub issue or both subs would pop.

 

[lovinthehd]

Or even use the different sub pre-outs switched around....to see if one pre-out may have the issue.

 

[Scotty19]

I will try that tomorrow. I switched the left and right cables with the same problem.

 

[Scotty19]

What I don’t understand is why there’s no issue with only one subwoofer running but the problem is when both are turned on. The left subwoofer by itself has no issue until the right one is turned on

 

[lovinthehd]

What I don’t understand is why there’s no issue with only one subwoofer running but the problem is when both are turned on. The left subwoofer by itself has no issue until the right one is turned on

I just wouldn't focus on that particularly as proof of anything. I'd still eliminate possibilities first.

 

[lovinthehd]

Heck, maybe just run a splitter on the sub pre-out that doesn't pop as another test. At least don't think that model has separate settings for delay/level, just an internal splitter but not sure....

 

[Scotty19]

Okay thank you I will do a soft reset, switch left and right cables and switch the left and right subs. I never thought of a soft reset so I will do that tomorrow and then the other changes that were suggested

 

[lovinthehd]

Okay thank you I will do a soft reset, switch left and right cables and switch the left and right subs. I never thought of a soft reset so I will do that tomorrow and then the other changes that were suggested

Ya just gotta do the elimination of possibilities thing when troubleshooting many audio/video issues....

 

[Scotty19]

I think I may have a splitter in the house somewhere and I can try that also

 

[Scotty19]

Thank you for all of the suggestions, I will post tomorrow if they make a difference

 

[TLS Guy]

What I don’t understand is why there’s no issue with only one subwoofer running but the problem is when both are turned on. The left subwoofer by itself has no issue until the right one is turned on

That really is the puzzle. Applied logic would indicate the problem is in the right subwoofer. I suspect there is something like a DC blocking cap going bad in the right subwoofer, feeding intermittent voltage spikes to the left subwoofer. To prove it move the subs physically, but do not change the wiring and see if the pop then occurs on the right.