Center channel vibrations/crackling

[davef]

Hi trekkerj!

Could you better describe what you are specifically hearing? I will try to help..

When you say vibrations, would this be closer to:

1. A crackly or static sound like crumbling tinfoil in your hand?
2. A specific rattling sound like something loose is vibrating against something else.

Is this sound volume dependant? Is It heard at all volume levels or at just loud volumes?

What reciever are you using? What television?

Thanks for your time.


Good Sound To You!

David Fabrikant
www.ascendacoustics.com

[trekkerj]

OK, it's difficult to describe. It definitely is volume dependent. I have dynamic range control on my receiver OFF. High volume, high frequency audio seems to produce this distortion I'm hearing. It's like the volume is too high (but it's not). If I heard the same thing in a .wav file, I could use a low-pass filter or normalize the volume. Shouldn't this speaker be able to handle these things better?
I have a Pioneer VXS-D509S receiver with a Toshiba 57HDX82 TV.

[davef]

Hi trekkerj,

I believe what you are experiencing is your receiver "clipping". This is caused when too much power is being demanded from your receiver's amplifier, more than it is able to supply. This will cause the normally rounded sine waves of the signal to be clipped and look more like square waves. The result is a high level of distortion which typically sounds like crackling and is extremely volume dependant. Again, this is being produced by your reciever, not the speaker, which is why you have heard it with two completely different speakers.

The reason you hear it out of the center channel is that for a movie soundtrack, at least 70% of all sound is directed towards the center.

Our 340 center is capable of handling a tremendous amount of power, however, it is simply reproducing the signal it is being fed.

I would suggest that you upgrade your receiver, or, if your receiver has center pre-amp outputs, add an additional amplifier just for the center channel usage. This has many additional advantages as well.

It is also very possible that your receiver could have something wrong.

Hope this helps!




Good Sound To You!

David Fabrikant
www.ascendacoustics.com

[trekkerj]

Great, just what I needed to hear.

Do you have any recommendations for any receivers or amps? Is there any way to test this theory before spending additional money?

Are there any specs for my receiver that you could look at and see if it might be an issue?

BTW, i say it's volume dependent, but I'm still not really 'blasting' the volume very high. I don't know if it's clipping, it sounds more like a vibration.

[davef]

Hi trekkerj,

I have already checked specifications on your receiver and this did help confirm my conclusions.

There is no simple way for you to 100% confirm this. First off, what speakers are you using for your left / rights? You could try placing one of your left/right speakers in place of the center and turn up the volume of the center so that it matches the same volume level when you heard the distortion from the 340 center. If you still hear the distortion, absolutely a receiver issue...

We now sell H/K receivers which are well know for the high current capability their amplifiers can provide. These have considerable headroom which is what you need. Give us a call or send me an email and I would be happy to offer you a great price on a unit.


Good Sound To You!

David Fabrikant
www.ascendacoustics.com

[trekkerj]

So what about my receiver helped you reach your conclusion? I want to understand this more.

Currently, I still have the cheapo Jensen speakers as left/rights. I ordered 4 CBM-170s to replace those.

Also, turning up the volume to a certain level doesn't product distortions all the time. The is usually during certain vocal sounds that causes a small vibration off of something.

[azanon]

I've noticed a little crackly sound out of my left front 170 when i really turn the volume up to "45" on my sony receiver, trekkerj. When i push it past "55", they all start sounding like mush. I dont have a decibel meter with me, but "45" is pretty loud - not uncomfortable loud, but i wouldnt want to listen at that volume for 4 hours every day as to probably have long term hearing loss. Thing is i have a 200 dollar sony receiver. I'm pretty sure its the culprit, because at, say, "30", all 5 speakers sound like a dream.

Bradley

[BradJudy]

Bradley,

Be careful - it sounds like your amp is clipping at high levels and clipping can damage speakers. Either keep the volume down or get a new receiver.

Brad

[trekkerj]

The crackling doesn't happen at very loud volume levels. However, my Pioneer is infamous for needing loud volume readings. A good volume level for me is -35db. I think the crackling is at the source, but I'm not 100% sure. However, my new 340c center doesn't impress me (or at least, it doesn't sound like a $200 improvement). At least not yet. I am still running my 4 front/surrounds from my cheap Jensen set. So I am reserving judgement for when I get the 4 170's and calibrate the speakers. Hopefully that will make it all come together. For now, the center sounds like it has more bass response, but I can simulate that on my old center by turning up the sub volume.

<blockquote id="quote"><font size="1" face="Arial, Verdana, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Originally posted by azanon

I've noticed a little crackly sound out of my left front 170 when i really turn the volume up to "45" on my sony receiver, trekkerj. When i push it past "55", they all start sounding like mush. I dont have a decibel meter with me, but "45" is pretty loud - not uncomfortable loud, but i wouldnt want to listen at that volume for 4 hours every day as to probably have long term hearing loss. Thing is i have a 200 dollar sony receiver. I'm pretty sure its the culprit, because at, say, "30", all 5 speakers sound like a dream.

Bradley
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

[azanon]

Brad,

Oh i didnt know that. I was trying to tear up the Sony so my wife would go for me needing a new receiver. Dont want to ruin the Ascends in the process!

Bradley