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Discussion Starter · #1 ·
Hello,


I have a pair of Definitive Pro Tower 400 amplified speakers. When they are turned on they emit a loud thump sound. Will this damage the speakers or is it normal for amplified speakers to do this?


What is the best way to power them:


1) Use the switched outlets on my amplifier and let it "thump" when turning on the amp.

2) Leave them plugged into the UPS power source all the time to avoid the "thump" when starting the amp.


Thank you for the help.
 

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I would never plug powered speakers into an accessory outlet on a receiver. Plug them into the wall and see if they still thump. Those amps draw enough current that they should go directly into the wall. Don't ever plug a subwoofer's power cord into a receiver, either.
 

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Discussion Starter · #3 ·
They only thump when power is first applied.


If I keep them plugged in all the time do you know how much power they draw when not in use?


I purchased a UPS power supply so they will not "thump" ever time the power flickers.


Thank you for the help.
 

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I have the Def. Tech. 2002 TL powered spkrs..

I have them plugged in to a power conditioner and that particular receptacle (on the back of the conditioner) is set to "always on".

If I'm explaining this right, the sub-woofer amp goes into standby mode after several minutes where there is no signal. This can be verified by a small red LED on the rear of the spkr., which also shuts off after several minutes of no signal. No thump this way.

There was a time when I didn't know how to stop this, but it didn't cause any problem.
 

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Discussion Starter · #5 ·
Great guys.... I get it now.


I plugged them into a my ups and the red light is on but it does go off after a few minutes with no signal from the receiver.


I originally had it this way but I was startled awake a few times in the dead of night with that loud thump sound... It sounded like someone breaking in!!
 
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