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Connecting a powered subwoofer to integrated amp

ddilillo

ddilillo

New Member
I connected a powered subwoofer to my two channel integrated amp using speaker wire going from the amp's speaker B terminals to the sub's high level input. My L & R speakers are connected to the speaker A terminals. Everything works at low volume but when I turn it up for a while, the amp seems to shut down. Any idea what's happening? Am I straining the amp with an impedance mismatch?
 
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The impedance presented by the sub is ridiculously high and would be nearly transparent to the amp. What happens if you disconnect the sub and run at the same volume for the same amount of time?
 
What integrated amp? What subwoofer?

With a powered sub, the impedance your integrated amp will see is normally so high as to be insignificant.
 
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ddilillo said:
I connected a powered subwoofer to my two channel integrated amp using speaker wire going from the amp's speaker B terminals to the sub's high level input. My L & R speakers are connected to the speaker A terminals. Everything works at low volume but when I turn it up for a while, the amp seems to shut down. Any idea what's happening? Am I straining the amp with an impedance mismatch?
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I'm curious. How are you connecting to the sub's high-level input with speaker wire? What subwoofer and integrated amp are you using? These things might give us some clues into what your problem might be.
 
You say you are running the sub from speaker B terminals and a set of speakers from the speaker A terminal. My question is: Does your sub also have its own set of speaker outs? All subs I have seen have both speaker inputs and speaker outputs. If you run the wire into the speaker inputs on the sub, you might want to run another set of speakers on the subs output. That may be where your impedance mismatch comes from. I have a powered sub that is connected to my Yamaha CR-2040. Either speaker B or C, cant remember which, but I also have two small speakers run off the subs speaker output. Can listen at any volume level for any amount of time with no problems. Remember, since it is a high level input, the sub is getting ALL frequencies so it has to have a crossover inside to split up those frequencies so the sub can get the lows. It then sends the rest of the frequencies out the speaker outputs. Since you have nothing attached there, the sub may sense an impedance mismatch and shut down. Just a thought.
 
chris35745 said:
You say you are running the sub from speaker B terminals and a set of speakers from the speaker A terminal. My question is: Does your sub also have its own set of speaker outs? All subs I have seen have both speaker inputs and speaker outputs. If you run the wire into the speaker inputs on the sub, you might want to run another set of speakers on the subs output. That may be where your impedance mismatch comes from. I have a powered sub that is connected to my Yamaha CR-2040. Either speaker B or C, cant remember which, but I also have two small speakers run off the subs speaker output. Can listen at any volume level for any amount of time with no problems. Remember, since it is a high level input, the sub is getting ALL frequencies so it has to have a crossover inside to split up those frequencies so the sub can get the lows. It then sends the rest of the frequencies out the speaker outputs. Since you have nothing attached there, the sub may sense an impedance mismatch and shut down. Just a thought.
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The speaker outputs from a powered sub are there only as a convenience, unless the sub has a high pass crossover built into it...which is not at all common. Even then, you can use them, or use the speaker output from your main amp. Either way, there is no resulting "impedance mismatch".
 
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jayvis said:
I'm curious. How are you connecting to the sub's high-level input with speaker wire? What subwoofer and integrated amp are you using? These things might give us some clues into what your problem might be.
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What else would one use to connect to the high-level (aka speaker-level) inputs?
 
It's a KEF Kube 12b subwoofer and a Tandberg 3012 integrated. Here's the back of the subwoofer. I am connecting speaker wire from the "speaker input" to the B terminals on the Tandberg.
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I know the sub presents a very small load to the Amp, But I'd check to see the speaker and sub wires are correct, that is in phase.

I once had an Amp shut down with power meters connected out of phase, and they, like the sub present a very small load.
 
That particular sub does not contain speaker outs so your initial connection is probably the best way to go. This connection should still not present any extra load on your receiver.

Other brands of powered subs that have speaker inputs and outputs, they are just straight run throughs and the sub amplifier is just tapping into the speakers. Still should be no load. Powered subs are (for the most part) built the same as far as inputs are concerned.

Passive subwoofer speakers are a different beast.
 
Rick Vestal said:
The impedance presented by the sub is ridiculously high and would be nearly transparent to the amp. What happens if you disconnect the sub and run at the same volume for the same amount of time?
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This is good test. I would also try running the sub by itself without the main speakers connected.
 
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