Crackling Noise When Recording

[PhilGnFla]

The problem:
When I start recording my first track, using either my guitar, mic, or keyboard, it sounds fine up until around 25-27 seconds in and I start hearing a crackling noise in the background. I have only recorded just under 40 seconds so far, but when the noise begins, it continues to the end.

My configuration:
I have a 2006 Dell Deminsion E510 running Windows XP. I am using the mic-in on the front of the PC. The input for the guitar and keyboard is one of two configurations; through a Tascam mixer/recorder or directly to the PC mic-in. I have a Sure SM48 mic so it is always plugged into the Tascam. I am only recording one input at a time (mic, or guitar, or keyboard).
First configuration: I have an old 4 track Tascam mixer/tape recorder (which has 8 inputs). The mic, guitar, and keyboard are all plugged into the Tascam. I use the Tascam line-out (L and R) outputs through a cable that mixes the output down to one 1/8" plug (with 2 rings) that goes into the PC's mic input. I use the trims and gains on the Tascam to control the input/output volumes going to the PC.
Second configuration: I have also used an adapter plug (with 2 rings) to get from the 1/4" jack to the 1/8" jack for the guitar and keyboard and plugged them directly into the PC's mic-in.

So, anyway, like I said, for both configurations the recording sounds fine for the first 25-27 seconds then I start getting the crackling noise. Any ideas?

Thanx,
phil g.

[steve]

Ideas? Yes. The sound card is letting you down. That is not at all uncommon because it is one of the first corners that PC manufacturers cut.

To be perfectly honest, an SM458 into a Tascam mixer/recorder is not A1, but it should be pretty decent, and you're not geting pretty decent, which leads to the next thing in the chain which is the sound card..There are a couple of "tricks" that the manufactures use to give the impression that their sound cards are not really as bad as they really are. One trick is "Noise Reduction" and the other is "Echo cancellation". The names sometimes change, but these type of effects are about cancelling out noise. If you disable all of these effects, then the inherent noise of the sound card becomes constant, but at least the recorded signal is not coming and going. Switching off all effects gives you the opportunity of getting consistent recordings, but ultimately you need to upgrade your sound card. If you are using an "on-board sound card", then that is the weakest link.

[PhilGnFla]

Hey Steve. Thanks for the reply. Yep! I was suspecting the sound card also. Just wanted someone else to convince me I was thinking o.k. So, again thanks for the input.

Now, you said something about, "an on board sound card". Well, that is exactly what I have. (It is part of the modem I think.) So, can I buy a new sound card and add it in one of my open slots? Can you recommend a good sound card? Or should I bite the bullet and get a new computer with the correct sound card (and more/faster memory)?

Thanx again,
phil g.

[steve]

PCI and USB sound cards have both been around for a good while and are likely to be with us for a good while to come, so if you upgrade your sound card now and upgrade the computer later you can move the sound card to the new computer.

USB devices are popular because they can be used with laptops, they do not require opening the computer case (just plug into the USB port) and the important analogue electronics are well away from the electrically noisy parts of the computer. The main disadvantage is that USB is processor dependent and if the processor usage touches 100% then the sound card looses synchronisation with the computer and the recorded sound turns to static. USB sound cards can be a bit prone to connection problems - the sound breaking up, the device being unavailable, and such like. I use a cheap USB sound card (Behringer UCA 202) with my laptop and it has been great - nice sound and no trouble at all, but this forum is littered with questions about USB problems.

I've used M-Audio USB interfaces and the sound is good, the build quality is OK but plastic, and sometimes the device needs to be removed and restarted to get it working.

PCI sound cards have a potential for picking up electrical noise from inside the computer. Personally I've never had any problem with that but I've seen reports of such problems. Some of the more expensive PCI sound cards use a "breakout box" that contains the analogue electronics to avoid this problem. When installing a PCI sound card it is probably best to try and keep it a little bit away from the power supply and if possible keep a free slot between it and other cards so as to avoid picking up interference. It depends on the motherboard layout whether you can do this, but as I said, I've never had interference problems with PCI sound cards.

The big advantage of PCI sound cards is that once they are correctly installed they should be pretty well problem free. They do not give problems about not being connected, or the sound breaking up (though such problems can still occur due to other reasons such as disk fragmentation or software hogging CPU, RAM or other resources).

Many PCI sound cards are very much orientated to playing computer games. For recording you will do much better with one that is designed for music use.

I've used M-Audio 2496 sound cards on Windows and they work very well with Audacity. They do not have mic level inputs, just line level in/out (and MIDI).

On-board sound cards (on the motherboard) can be disabled in the BIOS set-up. It is generally a good idea to do this if you install a PCI sound card.

Sound cards (as with much hardware) often come bundled with loads of crapware. You need to install the "drivers" but most of the rest of the junk can be left off your computer. Always check what you are installing before you install it.

[PhilGnFla]

Hey Steve, thanks for the info. Now I just have to convince myself my PC is worth investing in upgrades, or if I should get a new faster/bigger one first, either with a better sound card, or then add a better sound card.

[steve]

PC specifications are not the all and everything. I had an old Pentium II 500MHz computer with a SoundBlaster Live value and plenty of free disk space which worked really well for recording. It eventually got replaced, mostly for the benefit of other programs. With a low spec machine, it is more important that it is kept in a well maintained state. The old PII was used for little other than e-mail, web browsing and recording and Windows was routinely reinstalled once a year.