Crackling in Speakers

[Redbone]

Ever since I hooked up my subwoofer my speakers have been acting a bit crazy- intermittently crackling and popping with static. They even buzz and crackle constantly when an electric appliance like a blender is being used in the Kitchen. I am told it might be a ground loop but Dr, Hsu told me that is not possible. What the heck is going on?????

 

[mtrycrafts]

Ever since I hooked up my subwoofer my speakers have been acting a bit crazy- intermittently crackling and popping with static. They even buzz and crackle constantly when an electric appliance like a blender is being used in the Kitchen. I am told it might be a ground loop but Dr, Hsu told me that is not possible. What the heck is going on?????

May want to experiment? Unplug the interconnect to the sub and see if it is still doing all these. If not, something is passed on through the interconnect.
A ground loop has a noise problem, fairly constant and not kitchen appliance.

What kind of power cord came with the Hsu, 2 prong or 3? Filters in the sub amp maybe broken?

What did Dr Hsu say besides not a ground loop? Any suggestion to check?

 

[Unregistered]

Is it all your speakers or just the ones around the sub?
Is your sub magnetically sheilded?

-If I had to guess I would say your sub is interfering with your speakers. Try moving the sub around. This should minimize your problem.

 

[Redbone]

Hsu said the rest of the system is at fault as it is definately not the sub. The sub has a three prong plug. I lived with the H/T system for three months without a sub and it never made any sort of crackle or pop noise before the sub was installed. I have an NAD T753 receiver??

It seems to be coming from just the back speakers but I am not positive as they are the closest speakers to the sitting area, the sub is magneticaly shielded.

I am sure some people have had radios or speakers that buzzed and crackeld when a kitchen appliance or hairdryer were being employed?

 

[mtrycrafts]

Is it all your speakers or just the ones around the sub?
Is your sub magnetically sheilded?

-If I had to guess I would say your sub is interfering with your speakers. Try moving the sub around. This should minimize your problem.

How would the sub interfere in his manner?

 

[mtrycrafts]

Hsu said the rest of the system is at fault as it is definately not the sub. The sub has a three prong plug. I lived with the H/T system for three months without a sub and it never made any sort of crackle or pop noise before the sub was installed. I have an NAD T753 receiver??

It seems to be coming from just the back speakers but I am not positive as they are the closest speakers to the sitting area, the sub is magneticaly shielded.

I am sure some people have had radios or speakers that buzzed and crackeld when a kitchen appliance or hairdryer were being employed?

Oh, OK, not sure why but I thought your sub was acting up. What happens if you unplug the interconnect to the sub with the sub still powered up? May need to turn the volume down, then back up after you unplug.

What prongs on the rest of the system, 2 prong or 3?

You may need to get a cheater adaptor just to test. That is an adaptor with 2 prongs and place it on the sub power cord, see if the speakers are still acting up. Or, if your sytem also has 3 prongs, do that one first and see. A process of elimination. Do you have cable TV cable hooked up to the system? If so, unplug that and see what happens.

 

[Redbone]

Excellent advice Mycrafts but the conundrum here is that the system did not have interference of this type before the sub was incorporated. My reciever has a three pronged plug and I heard that with the NAD units this could casue ground looping? I have replaced with a cheater plug. My sub is only a two prong configuration.

The crackle or pop if you will seems to come mostly from the rear speakers and at decent intervals sometimes 2-10 minutes apart. No idea or clue as to what is causing it.

 

[mtrycrafts]

Excellent advice Mycrafts but the conundrum here is that the system did not have interference of this type before the sub was incorporated. My reciever has a three pronged plug and I heard that with the NAD units this could casue ground looping? I have replaced with a cheater plug. My sub is only a two prong configuration.

The crackle or pop if you will seems to come mostly from the rear speakers and at decent intervals sometimes 2-10 minutes apart. No idea or clue as to what is causing it.

There is something interacting between these two power components. It is interesting that only your rear channel speaker is what is acting up.

Well, while it sounds different from a 'good' ground look symptom, it may be. Not a simple issue to get to the bottom of. One of your component has a 2 prong power plug, the other has a 3 prong.
Have you tried to reverse the sub plug? Or is it polarized with a wide blade on one side?
Do the speakers still pop with the cheater plugs on? Not a good practice for a permanent solution

Try the tests I suggested see if you can isolate the cause. Interconnect to the sub while the sub is still powered?
Or, pops could be a capacitor problem someplace? Except you also indicated that now other household equipment can cause poroblems and it didn't before.
No simple solution

Maybe someone has a link to the grounding issue at this site. I think there is such an article here someplace or
http://www.q-audio.com/grounding.pdf

 

[Redbone]

I put a two prong cheater plung on my NAD three prong plug. It seems to have fixed the problem I hope it is a viable and correct solution. All components in my system with the exception of the NAD have two prong plugs.

Why do you need a three prong plug and how does it effect a system?

 

[mtrycrafts]

I put a two prong cheater plung on my NAD three prong plug. It seems to have fixed the problem I hope it is a viable and correct solution. All components in my system with the exception of the NAD have two prong plugs.

Why do you need a three prong plug and how does it effect a system?

OK. If that 2 prong cheater fixed it, there is an interaction between the two through the grounding. Cheating the ground in your main system can be dangerous if there is a short someplace. You, your family can get hurt?
That is how the main system is grounded. the cheater plug lifet it.
The Hsu used a different grounding method that was designed around the 2 prong plug.
Just be very careful.

 

[Unregistered]

I put a two prong cheater plung on my NAD three prong plug. It seems to have fixed the problem I hope it is a viable and correct solution. All components in my system with the exception of the NAD have two prong plugs.

Why do you need a three prong plug and how does it effect a system?

The third prong on the plug is a safety ground. It is tied to the case of your receiver and is only there to provide a guaranteed path to ground in the event that there is a fault in the product that energizes the case or any other user-accessable area.

Your receiver (probably) has transistors mounted on heat sinks. The case of the transistor is usually at the negative rail voltage (-50V or so). If the insulator between the transistor and the heatsink were to fail and there were no third wire in place, then the heatsinks would be at a -50V potential, and since the heatsinks are usually screwed to the chassis at some point, then the chassis would also be at -50V. Potentially hazardous for the user.

With the third wire in place, the chassis is guaranteed a low-impedance path to ground. If the insulator fails and the third wire is in place, then the amplifier's -50V supply is connected to ground, which blows the AC fuse on the receiver, protecting the user.

The third wire is a requirement for UL listing and is just safe practice anyway. Your other components do not have a third wire because they are low power devices and do not constitute a safety hazard, are double insulated, or conform to certain internal component spacing rules (or some combination of these three).

 

[Unregistered]

Oops, about the crackling. Some appliance motors use brushes to deliver current to the armature. This kind of design interrupts the current with a gap which generates a constant sparking. This sparking puts high voltage spikes back on the AC circuit, and also generates a LOT of broadband EMI.

If lifting the safety ground eliminated the crackling sound, then the sound may have been a result of the motor's voltage spikes appearing on the safety ground wire (in the wall) either conducted or due to the wire's acting as a receiving antenna. Why it only showed up on the rear speakers is unknown, but it may be that your rear speakers are driven by a lower power amplifier and thus do not have the same filtering/bypassing in their power supplies that your front speakers have.

 

[Redbone]

I believe the crackle was in all my speakers with the exception of the sub. I could predominantly hear the backs because I sit 4ft from them as opposed to 10ft from the fronts. I believe the Nano second crackles were coming from all speakers. I hope my receiver and my family will be safe with the two prong method?? I am kinda worried now that I have done something that is not supposed be done. Will this ruin my receiver?

 

[mtrycrafts]

I believe the crackle was in all my speakers with the exception of the sub. I could predominantly hear the backs because I sit 4ft from them as opposed to 10ft from the fronts. I believe the Nano second crackles were coming from all speakers. I hope my receiver and my family will be safe with the two prong method?? I am kinda worried now that I have done something that is not supposed be done. Will this ruin my receiver?

No, the cheater will not ruin your receiver. The safety issue is a consideration 'if ' something goes wron inside the receiver.
Chances are remote. You are more likely exposed to a greater risk driving the family around.

 

[Redbone]

Hmmm thanks for the info and the problem is solved....

 

[warnerwh]

I didn't see if anybody asked if you checked the polarity of the outlets if you're using more than one for your system. I'd make sure this was correct just out of habit. You can buy a polarity checker from any hardware store for 5 bucks. Having a cheater plug on won't hurt anything. The third prong is a safety ground. Both the neutral and safety ground commonly are tied together at the breaker box anyway. The reason I suggest a polarity checker is you want to be sure that hot and neutral aren't reversed in your outlets especially since you have two prong plugs everywhere. The polarity checker is easy to use as you just plug it in and there's three little lights. Don't worry about it that you don't have the third wire as many of us are old enough to remember when nothing had three prongs and we're all still alive. The extra wire is an extra safety precaution.