Crackling in Speakers

Posted by: bagman

Crackling in Speakers - 03/02/10 08:03 PM

My receiver is a 2002 Panasonic SA-ZR45. For the past few years a crackling sound has penetrated the speakers. When I shut the receiver off the crackling gees away. Until recently. Now, the crackling is on all the time and I had to switch to the TV speakers, not too good. What could be the cause of he crackling, and how can it be fixed? Or, should I invest in a new receiver?
Thanks.
Posted by: SirQuack

Re: Crackling in Speakers - 03/02/10 08:50 PM

I'm guessing the crackling might not be good for your speakers at louder levels, you've been allowing this for a few years, that would drive me crazy... what speakers are you using?
Posted by: Adrian

Re: Crackling in Speakers - 03/02/10 09:25 PM

Is it coming from both speakers?
Posted by: bagman

Re: Crackling in Speakers - 03/02/10 09:34 PM

I have 4 M 3s, a center and rear, and a sub (6 Total + sub). It comes from all, starting from the rear and working its way all around, one-by-one.
Posted by: Wid

Re: Crackling in Speakers - 03/02/10 09:39 PM


Is it all the time or just when you turn it up?
Posted by: bagman

Re: Crackling in Speakers - 03/02/10 11:20 PM

It happens now all the time. If fact I've had it off for the past five days.
Posted by: pmbuko

Re: Crackling in Speakers - 03/02/10 11:26 PM

Time to get a new receiver, I think, as it's likely not very cost-effective to get your current receiver serviced.
Posted by: JohnK

Re: Crackling in Speakers - 03/03/10 12:31 AM

Baggy, a more up-to-date receiver would probably be a good idea, but there's a possibility that this is simply the result of a dirty volume control. With the receiver turned off, run the volume control(if the unit does have a volume knob)rapidly up and down between the min and max settings at least a couple dozen times to see if this helps by cleaning it a bit.
Posted by: Murph

Re: Crackling in Speakers - 03/03/10 07:40 AM

I was thinking that too John. When I went searching for some info on roughly what year digital volume controls became more popular than analogue (prone to crackles,)I found this interesting statement in a short article discussing the pros and cons of both.

"A digital volume control has its own problems. Each 6dB reduction in volume from the maximum setting throws away one bit of resolution. A low volume setting (say, 30dB of attenuation) is equivalent to discarding five bits. If you had true 20-bit resolution in your D/A converter, you'd be listening to 15-bit audio instead of 20-bit. The lower the volume setting, the greater the loss in resolution. "

Anyone with better knowledge care to comment if this is still current and how relevant it is? Here is the link for reference purposes.

Volume Controls
Posted by: bagman

Re: Crackling in Speakers - 03/03/10 10:31 AM

John and Murph, Thanks for the tip, unfortunately it did not work. Looks like a new receiver is answer. Not a bad thing. Any recommendations on one with a price point lower than $400?
Again, thank you.
Posted by: pmbuko

Re: Crackling in Speakers - 03/03/10 11:25 AM

This Onkyo TX-SR507 5.1-channel receiver is $249.99 from Accessories4Less, a reputable store.
Posted by: CatBrat

Re: Crackling in Speakers - 03/03/10 11:35 AM

Here's another choice. I bought this Pioneer VSX-819H-K 5.1 receiver for my Son and he's satisfied with it. It's $305.99 from Best Buy.
Posted by: ClubNeon

Re: Crackling in Speakers - 03/03/10 11:48 AM

The new '20 series receivers from Pioneer will be hitting soon. While I bagged the '19s the new models look to be back in the game. May want to wait around for them to start showing up at your favorite store.
Posted by: Murph

Re: Crackling in Speakers - 03/03/10 11:51 AM

Youre welcome but don't take the quote I posted too seriously. That was more of a question than a helpful tidbit.

I shared it because it didn't make a lot of sense to me. Of course, I realize it said "equivalent of effecting the bit rate....", and didn't say it's really directly changing the bit rate as that would be a mess, so I'm curious to understand how that works, if it's true.

I also apologize for a possible derail but so far no one is biting so you are probably safe.

I do now agree you most likely need a new receiver. Unless you have a knowledgeable buddy with access to schematics and time to spare, I'm sure you would cost as much to repair as it would to buy a decent new one.
Posted by: ClubNeon

Re: Crackling in Speakers - 03/03/10 11:57 AM

 Originally Posted By: Murph
I was thinking that too John. When I went searching for some info on roughly what year digital volume controls became more popular than analogue (prone to crackles,)I found this interesting statement in a short article discussing the pros and cons of both.

"A digital volume control has its own problems. Each 6dB reduction in volume from the maximum setting throws away one bit of resolution. A low volume setting (say, 30dB of attenuation) is equivalent to discarding five bits. If you had true 20-bit resolution in your D/A converter, you'd be listening to 15-bit audio instead of 20-bit. The lower the volume setting, the greater the loss in resolution. "

Anyone with better knowledge care to comment if this is still current and how relevant it is? Here is the link for reference purposes.

Volume Controls

That article misses the most common type of volume control in use these days. It isn't digital, but a digitally controlled, stepped resistance, integrated circuit. Basically the line-level signal is fed through an IC. Another set of pins on the chip select how much attenuation is applied, and a lower amplitude analog signal is passed to the output pins. Not as "pure" as a true potentiometer, but no crackles, and no loss of dynamic range.

That said, it's possible to design a very high quality digital volume control which behaves more like an analog control rather just bit shifting. Windows Vista/7 actually has one implemented as its main level control.