computer noise

and what records it

so im sittin here,thinkin,i hear all this stuff bout silent pc’s and the latest gizmo to make yer machine super quiet,so i ask myself,besides a mic,what will record noise? will the soundcard itself pickup vibes frm the case and or fan while recording? ???

This isn’t really an answer to your question, but I use a laptop to record, then I transfer the files to a noisy desktop for all the mix down and midi tracks. I think you are correct, the only time noise gets introduced is during the recording procss. I am not sure if the sound card itself picks up the sounds or if the mics do. My mics are pretty far away from my labtop but I still get some noise unless I unplug the laptop and run it without the power plugged in.

Troy

Eyup!

All electronic components generate noise, the components which go to build a soundcard are no different.
The soundcard therefore generates its own noise, which you can do nothing about, and is also affected by noise radiated from all other components and wires inside the pc (and even from sources outside the pc!)

Ideally, the soundcard should be enclosed in a sealed metal enclosure and any gaps left for connectors should be as small as practicable. The metal enclosure should be connected to ground (chassis) via a short, stout lead. Any connecting leads should be filtered.

As I have yet to see a shielded soundcard, my best advice would be to mount it in a slot as far away from other cards, especially graphics cards, as possible, and dress all wires and cables so as to avoid it.

When you look at the noise specs for soundcards, always bear in mind these are never achieved in the real world. In practise, the electrical noise contributed by your pc will always be significant.

Beefy Tip no 47
If you hear a zippp… noise when you use your mouse, it is most likely noise radiated from the graphics card. Move the two cards as far apart as possible…

Beefy Tip no 63
If the noise level gradually increases after you have been using your computer for a while, you need better cooling.

Beefy Tip no 462
If you use a laptop, you’re stuffed :)

Steve

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As I have yet to see a shielded soundcard,


Behold, the Aardvark Lx6!

http://www.portlandmusiccompany.com/lx6.html

/uselesstrivia

My son and I both have Dell laptops that we use for recording. He has an external firewire audio interface (Edirol-FA10), and I have an external USB audio interface (M-Audio USB). On both lap tops, the external power supplies radiated so much interference that the power supplies had to be disconnected from the computers while recording. The problem was much reduced by wrapping the power cordfrom the wall-wart to the computer with conductive foil which was then connected to chassis ground on the audio interface using a jumper with alligator clips on both ends.

By the way, the noise was present whether or not a microphone was being used, and was similar in level on both computers/interfaces, and repositioning power supply and input leads to separate them as much as possible had no discernable effect. Maybe the noise was just too severe for this to help audibly. Anyway, although the foil wrap on the power cord looks pretty sloppy, it works.

T

The soundcard will not directly pickup noise from the computer, but it’s a good idea to keep it away from the graphics card when you install it.

I like using quiet computers whether I’m recording or not. You can check out my quiet DAWs at Custom DAW. Someone is going to complain about this plug but guys we’ve been over this - I don’t make any money selling these DAWs. I do it because I like to keep up with the technology & I like helping other people doing what I’m doing (home recording).

One of the nice things about using a digital interface and external analog converters is that the most sensitive analog signals are not brought into the extremely noisy interior of the computer. The computer itself is a broad-band radio source and virtually no analog circuit is completely immune to RF noise pick-up. By placing the low-level circuitry and analog converters in an external box (or separate digital mixer) the field-strength of the interfering signal can be significantly reduced, making protection easier and the consequences of residual pick-up less significant. While in-computer soundcards may be adequately shielded, external converters are less likely to pick-up RF noise and convert it into audio. If the converters are internal it is preferable to feed them with line level signals. The smaller the input signal, the larger any induced noise will be in relation to it. This is one of the reasons that the “mic” inputs of computers are so bad. Adding high-gain analog circuitry to such a noise-prone environment requires the manufacturer to design the circuitry very carefully and shield it well. Both of these things raise the cost and rarely done on general purpose soundcards.

The other common computer device which emits large amounts of radio frequency interference is a CRT monitor. Keep it away from the converters and cables or you might pick-up video related noises (buzz from vertical retrace, whine from horizontal retrace and a possible assortment of noises based on what is on the screen). An alternative to the CRT is to use an LCD monitor which uses much lower signal voltages and generates less interference.

Cooling fans are the big culprit for acoustic noise, followed by hard disk noise. I haven’t found an adequately quiet solution yet for cooling. I spent a fair amount on a Zalman cooler for my DAW only to find that it did not help very much despite its quiet rating. The CPU fan is still the loudest noise in my case. At some point I will try to quiet it down and may go to water cooling but for now I just close-mic whenever possible put absorbtive materials near the PC when I have to.

The noise that a cooling fan will produce is related to its speed and inversely related to its size but in addition, the specific construction of the case may allow more or less coupling between the fan vibrations and radiating surfaces in the case (including the motherboard). If you have ever listened to a tuning fork held in free-air then placed the butt on a table you will realize how much difference a “sounding-board” can make. Isolating the vibration of the fan from the case or mounting structure can help.

Jim

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for now I just close-mic whenever possible put absorbtive materials near the PC when I have to.


I usually prop 2-3 sofa cushions (“Absorbtive material”) around my PC case when I’m recording vocals or acoustic guitar. That cuts the noise by about 75-80 percent. That’s usually plenty for my purposes, since it’s easy enough to use EQ to cut the remaining hum, and the rest gets masked by the other elements of the mix. Of course, if every track in my mix were recorded acoustically, I could see how even that little bit would build up in an ugly way…

PR

So, it seems like the most quiet solution is a laptop with a USB breakout box for recording?

What about that Lexicon Box?

http://www.musiciansfriend.com/product…=245505

Since the box itself can be separated from the computer, doesn’t that help a great deal?

Troy

Laptops can be quiet but mine gets louder than my desktop when it decides it is too hot. This appears to be random although I am sure it is just a response to a temperature sensor. A sudden increase in fan noise can be a larger problem than a continuous low-level sound.

There are quiet desktop PCs and with sufficient effort and/or expenditure you can have one (This for example). That is probably “best” but a laptop is definitely convenient and usually quiet, especially for live or “field” recording since it is much more portable than a desktop system.

Jim

Quote (doghouseman @ June 19 2006,16:36)
So, it seems like the most quiet solution is a laptop with a USB breakout box for recording?


I think that either an external USB or firewire interfaces would be good from a noise perspective. My experience (based on a sample size of 2) is that you get lower latency with the firewire. Firewire certainly can support more inputs because of its greater bandwidth. So, price and quality being equal, I’d go with a firewire device.

T

I have a HP SFF DC5100 pc. The thing is #### near silent.

It’s got an interesting hybrid oil cooler / fan contraption to cool the CPU down with. The oil cooler thing sit on the CPU in a horizontal ‘pipe’ (square tube) the diameter of a old style powersupply fan that goes from the front to about 3/4 through the PC.

At the front of the ‘pipe’ is a fan with a variable speed controller.
Big fins, slow rotation. Can’t ever hear it.

Its got 5 ‘steps’ in its speed range. I’ve heard it once (under real heavy load) ‘step up’ to notch 2. Even then you have to listen with your ear close by to hear it. It basically just take the ‘ambient’ heat hanging around the oil cooler’s heatsink away.


BTW my laptop (HP nx9010) have this issue that it records HDD and mouse activity when plugged in. For some or other reason if I lift the ground from the powersupply to the wall outlet it gets waaaaay quieter. Could not figure it out yet. Maybe there’s a circuit that gets ‘closed’ when the ground is plugged in ?

It doesn’t sound like ground hum. It sounds like the HDD going, and it corresponds to the HDD indicator LED … weird.

my .02

W.

Quote (Wihan Stemmet @ June 20 2006,07:55)

BTW my laptop (HP nx9010) have this issue that it records HDD and mouse activity when plugged in. For some or other reason if I lift the ground from the powersupply to the wall outlet it gets waaaaay quieter. Could not figure it out yet. Maybe there’s a circuit that gets ‘closed’ when the ground is plugged in ?


This is the same thing that happens with our Dell laptops - Every time the system performs a disk access when the external power supply is plugged in, noise is generated. The power cable seems to act like an antenna that transmits RF generated by the disk drive. The RF seems to be picked up by the audio cables leading to my audio interface even though they are shielded. Unplug the power supply, and disk whine is gone.

T

that shielded ardvark looks like it mite be worth a try,lotta stuff for only 249.00
anyone have any experience with the ardvark products???? :D :blues:

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anyone have any experience with the ardvark products???? :D :blues:


No personally. Katow here used to have the 6x and 10x running in a machine together.

Me, I wouldn’t recommend them these days as Aardvark is out of business.

My CD ROM was creating all kinds of weird noise. Have no idea why or how, but it was giving me grief just playing CDs. I came across a great sale on a DVD player/CDRW. It’s a bunch mo-quiet.

Gee, lots of info here. But the simple answer is, the only reason you’d need a super-quiet computer is when recording using a microphone. Or if the noise bugs you, of course! :wink:

If you always record from electronic/electric instruments, or are using softsynths, then the fan noise only matters if it’s loud enough to interfere when you’re trying to listen to your monitors. (Which probably isn’t a big issue, and you can just stick a bunch of foam between you and the computer if it is an issue.)

alright,!!! thats what i was lookin for,didnt know if the machine would pick up machine noises also,as far as it buggin me,#### im deaf anyways,thats not a problem,and i can see isolating it somewhere or recording far enough away from it as not to pick up anything with a mic,thanks guys for the inputs,carry on.:blues: