Problem with Rcvr or Powered Sub?

[tracer-mag]

I posted this earlier in the Beginner and Audiophyte forum.

I have a very basic home theater setup and am having a problem with one or both of the following pieces: Onkyo TX-DS595 5.1 Receiver and JBL 5pc satellite speaker system, with 100 Watt powered Sub, connected to the Onkyo with the low frequency cable. The sub has a power switch on back, an adjustment knob for the sub intesity, a seletors switch for "Auto" or "On" and a green/red LED. I normally have the swithc set to Auto, and it is my understanding that the sub will detect signal from the receiver and turn itself on or off accordingly.

Possibly important facts: I just moved from a new apartment building into a home; the home is about 35 years old. Prior to moving I had no problems with the system.

Problem: I have hooked up the system as it was prior to the move. The sub is routinely making a fast popping sound, almost sounds like a machine gun! It happens when initially turning the power switch on the sub to the on position, regardless of whether the receiver is on or off. I can get the sound to stop by moving the selector swithc on the sub from Auto to On, and when returning the switch to Auto, the sound does not return immediately. But, after about 10 minutes or so it repeats the problem. In the interim, the sub operates normally whether listening to music or watching movies.

I do not know if this is "clipping" or something else. I am concerned that maybe the sub is not getting enouch power or something like that.

Any help will be greatly appreciated.

TR

 

[MDS]

It sounds like the auto-on is turning the sub on and then off again a short time later. You may be able to fix that by adjusting the subwoofer out level on the receiver and the volume knob on the sub. You really need to do at least a basic calibration of all channels (including the sub) using the receiver's test tones and an SPL meter.

Then again, if it happens when you first turn the sub on then it could have something to do with the power. Is the sub connected to an outlet that is shared by other appliances in the house - like the fridge or dishwasher? That could cause power spikes when those appliances cycle on and off. Try moving the sub to its own dedicated outlet.

 

[tracer-mag]

Thanks for your reply. The sub is plugged into a wall outlet; the other plug from that outlet is a power strip where the receiver, dvd palyer, tivo, tv, and vcr are plugged in.

 

[mtrycrafts]

Is the sub connected to an outlet that is shared by other appliances in the house - like the fridge or dishwasher? That could cause power spikes when those appliances cycle on and off. Try moving the sub to its own dedicated outlet.

If he has the pop every time, that would be an interesting coincidence for an appliance to go on just at that time, every time he powers it up

It sounds like either the muting circut is not working, if it has one, the speaker gets a spike from the insrushing current to the power filtering circuit that is not properly blocked?

 

[MDS]

Could be. Who knows? Just thinking thru some possibilities.

Now he did say that it happens the first time the sub is turned on and that is probably in-rush current as you describe, but he also said that it happens a few minutes after turning the sub from on to auto and that may be caused by other devices on the same circuit cycling on and off.

I've been at this stuff for some time and I (fortunately) have never had some of these strange issues that people ask about. I feel like I'm missing out...everything just works for me.

 

[mtrycrafts]

Could be. Who knows? Just thinking thru some possibilities.

Now he did say that it happens the first time the sub is turned on and that is probably in-rush current as you describe, but he also said that it happens a few minutes after turning the sub from on to auto and that may be caused by other devices on the same circuit cycling on and off.

I've been at this stuff for some time and I (fortunately) have never had some of these strange issues that people ask about. I feel like I'm missing out...everything just works for me.

If it happens at the moment of switching to auto, I would think it is an internal amp problem, but it seems it is either way, including that inrush current
Perhaps in switching to auto, it turns off cap discharges perhaps, while waiting for the right amount of signal to turn on again? I hate those auto on features.