DIY soundsystem has started to crackle, and overall sound quality has diminished?

[Jables66]

Not sure if this is the right place to post, but hey.

I set up my own many-speaker sound system for my PC using two sets of PC speakers (front and side pair, respectively) and for the centre/subwoofer output, I'm using a 100W Kustom guitar amplifier, which I'm transferring sound to via a 3.5mm to 3.5mm (+ 1/4" jack adaptor on one end), plugged into the centre/sub output on my PC and into the CD/Tape input on the amp.

Only recently, it's become noticeable that when playing music or sounds coming from my PC, there's a very noticeable crackle, and sometimes the audio quality drops to that of an old VHS, where the sound skips.

My suspicion is that I've worn out the speakers, since the audio software I'm using to support this Frankenstein's Monster of a sound system (Realtek HD Audio/ AC'97) allows me to allocate dB where I see fit. So naturally, to get the most bass out of my 'woofer, the max of 10dB has been allocated to the amp, and to even things out so that the other speakers aren't drowned out, all the other speakers have had the maximum allocation of decibels given to them as well. The one thing that negates my theory is that the amp is doing playing this poor sound as well. The amp can't be worn out, since I bought it a few months ago brand new, and I imagine the two 12" Celestion speakers are more than capable of handling the load.

All of the connections seem fine, so my next theory is a software issue.

Anyway, I apologise for rambling, but this has frustrated me no end.

Thanks, Jack

EDIT: Okay, I've performed a small experiment with my audio hardware, as perhaps I should've done before posting.
Very simply, I turned off a set of speakers at a time while playing music (rather loudly) in order to determine the culprit, if it is indeed a hardware issue. This experiment reveals that my amp is occasionally making popping noises, and the speakers are crackling (but nowhere near as badly as when the amp is on). I've heard that this kind of thing can happen with bigger guitar amps when the speakers aren't broken in yet or "stretched". The general procedure is to play on it, increasing the volume at 1/10th increments or something. I haven't done this yet, as the sound-proofing in this house is shite, and I'm afraid it'll have a detrimental affect on my two fish. Is this a plausible conclusion?

Also, one more thing I've uncovered while playing around with the amp's inputs and outputs (euphemism, right there...) is that running the cable from my PC to the effects return socket rather than the CD/Tape input has somehow tripled the bass output. So much so that I've already had a complaint from a neighbour.

 

[lsiberian]

This sounds like a mess to me. Engineering rule #1 Keep it simple.

1 Lets get those gains all to 0db and try not to max them out

2 I'd definitely suggest an amp designed for use with speakers and not guitars.

www.parts-express.com has Sure amps which can do the job.

3 Lets ditch the PC speakers and get some speakers designed for good sound. The Behringer 2030p's would be a substantial upgrade from your current speakers.

You want to simplify whatever you can in a system. Complex setups are impossible to troubleshoot. Simple systems are easy to trouble shoot.

 

[Jables66]

Alright, I'll give that a shot. Thanks man

 

[highfigh]

This sounds like a mess to me. Engineering rule #1 Keep it simple.

That's not true, and you know it!

Engineering rule #1 is:

Get a pocket protector and fill it with pencils, pens, a stainless 6" ruler, a few paperclips, some string,....

Oh, and make sure to have some white adhesive tape for those nifty black horn-rimmed glasses.

 

[sholling]

This sounds like a mess to me. Engineering rule #1 Keep it simple.

1 Lets get those gains all to 0db and try not to max them out

2 I'd definitely suggest an amp designed for use with speakers and not guitars.

www.parts-express.com has Sure amps which can do the job.

3 Lets ditch the PC speakers and get some speakers designed for good sound. The Behringer 2030p's would be a substantial upgrade from your current speakers.

You want to simplify whatever you can in a system. Complex setups are impossible to troubleshoot. Simple systems are easy to trouble shoot.

Very good advice. Even a used Craig's List receiver and the B2030Ps would be a huge improvement.

 

[Shock]

Never...ever...ever...use onboard audio. It suffers from huge interferance and is just plain bad.

Buy yourself a soundcard.

 

[Jables66]

Thanks for all your help, guys. Forums are much more useful than I initially thought. I have been searching eBay, Craigslist and UK based audio specialists for an idea 5.1/7.1 surround system, but no joy thus far. Freshly out of College, you see (with diploma in mechanical engineering, as it happens. So this advice has been a little embarrassing for me).

Though I have managed to discover the original problem with my current setup. I went through every change I made to my audio related software, and that came up with nothing. So, I then re-checked my hardware. As it turns out, the new effects unit/ pedal board was the cause of the interference, and since I have started to disconnect both the power to the pedal board and its input to the amp, the crackling and popping has ceased.

However, you're all right. I definitely need to replace these PC speakers. They're suffering from the same affliction that the volume pots on my older guitars are, in that they've become extremely scratchy.

 

[Knucklehead90]

While I have to admire you for using what was on hand to cobble a sound system together - remind me not to hire you to re-wire my home.