sound cards electrical noise aluminum foil EM shielding

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dan
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sound cards electrical noise aluminum foil EM shielding

Post by dan » Tue Jul 05, 2005 1:53 pm

i decided there's enough differences between this subject and an earlier post to post this as a new topic ...

but it's my understanidng the reason on-board audio doesn't sound as good as card is due to electrical noise/interference taht a seperate card is better able to isolate.

which makes me curious-- would EM shielding your pci sound card, perhaps by wrapping it in aluminum foil - improve its sound quality?

if so, why don't sound card manufactorers EM shield their cards?

also would other components, such modem, wireless g card, etc benefit from EM shielding and if the would is wrapping them in aluminum foil a good way to achieve this?

perplex
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Post by perplex » Tue Jul 05, 2005 2:21 pm

the reason on-board sound doesnt sound as good as a card is because of low quality components and lack of components that a card will have.

EM shielding will help, But you won't notice unless your PSU doesn't have a case or you have some other big EM emitter like a TV next to your case. The other reason you won't notice is because your speakers/headphones,soundcard are not audiophile standard maybe :?

Lastly, the power going into your soundcard isn't perfectly regulated as it's AC converted to DC. So it's not as clean as a battery's power output.

dan
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Post by dan » Tue Jul 05, 2005 2:28 pm

with a wireless g card, fax modem card, and sound card EM in PCI slots adjacent to one another, and maybe the video card as well, interfere with one another? also what would be an effective way to reduce EMI?

- apart from sound quality issues, would EMi also interfere with graphics, modem, networking NIC?

perplex
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Post by perplex » Tue Jul 05, 2005 3:04 pm

probably but again i doubt you'd notice. i dont think any interference would effect DVI because it's digital, but maybe because it may effect the components :?

dan
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Post by dan » Tue Jul 05, 2005 4:32 pm

actually my matrox g450 is analog not digital :)

would it be safe to use aluminum foil as it is electrically conducting?

geforce1
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Post by geforce1 » Tue Jul 05, 2005 4:46 pm

I doubt that wrapping a sound card in aluminum foil would be such a good idea. The only thing you'll hear from the card would be sparks :-)

EDIT: As for trying to reduce EMI, some motherboard BIOSes have spread spectrum settings for the CPU (more common) and the PCI/AGP (less common). Be careful if you're overclocking with spread spectrum turned on.
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dan
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Post by dan » Tue Jul 05, 2005 4:55 pm

geforce1 wrote:I doubt that wrapping a sound card in aluminum foil would be such a good idea. The only thing you'll hear from the card would be sparks :-)

EDIT: As for trying to reduce EMI, some motherboard BIOSes have spread spectrum settings for the CPU (more common) and the PCI/AGP (less common). Be careful if you're overclocking with spread spectrum turned on.
thanks for the warning!!!! still i wonder if it could be a viable product.

You know, i've wondered what spread spectrum was for.

sthayashi
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Post by sthayashi » Tue Jul 05, 2005 6:58 pm

dan wrote:
geforce1 wrote:I doubt that wrapping a sound card in aluminum foil would be such a good idea. The only thing you'll hear from the card would be sparks :-)

EDIT: As for trying to reduce EMI, some motherboard BIOSes have spread spectrum settings for the CPU (more common) and the PCI/AGP (less common). Be careful if you're overclocking with spread spectrum turned on.
thanks for the warning!!!! still i wonder if it could be a viable product.

You know, i've wondered what spread spectrum was for.
F*** up the design a bit and you make yourself a nice handy antenna. Just what you wanted in your sound card, right?
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|Romeo|
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Post by |Romeo| » Wed Jul 06, 2005 3:20 pm

sthayashi wrote:
dan wrote:
thanks for the warning!!!! still i wonder if it could be a viable product.

You know, i've wondered what spread spectrum was for.
F*** up the design a bit and you make yourself a nice handy antenna. Just what you wanted in your sound card, right?
Pay attention to the above; it's quite likely that whoever designed the sound card knew a lot more about shielding than you do -it's quite a specialised and can cost a lot of money to get a specialist in if you get it wrong during design :oops:

CX23882-19
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Post by CX23882-19 » Fri Jul 08, 2005 5:00 am

I'd keep Spread Spectrum OFF, particularly if you have an nForce2 based motherboard. The interrupts get screwed with it on (on NF2) and the result will be even worse sound quality in the form of squawks and clicks.

Given what sound cards can achieve in actual real-word tests anyway (>100dB SNR) I think it's a moot point. Of course audiophiles will argue the toss about it, but that's to be expected. :)

ronrem
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Post by ronrem » Fri Jul 08, 2005 7:54 pm

Both MSI and ECS have mobos with special pci slots that give a cleaner interface for a soundcard. You want to be sure the psu was designed to have low emissions,good sheilding,filtering. Be sure case ground is good.

I suspect a high powered Vid card nearby could be a concern too.

Mar.
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Post by Mar. » Fri Jul 08, 2005 8:40 pm

I seriously doubt that the same components that are used for an onboard sound device, would magically produce better sound if tied into a PCI card.

As far as wrapping a sound card in tinfoil, wtf?!? Of course it's unsafe! Even if you somehow didn't bridge any electrical connections, which is sure to happen, those IC's and caps radiate heat, which needs to be carried away by airflow, if even a little...
~mar.

m0002a
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Post by m0002a » Fri Jul 08, 2005 10:35 pm

I have a SP/DIF cable from the digital output of my optical drive connected directly to my soundcard. Given the length of wire and the path it takes from the optical drive to the sound card, I thought this was the most important thing to shield, so I replaced the wire on the OEM cable with 18 AWG twisted pair with foil shielding (I already had some of this cable). The audio card itself is in the next-to-last PCI slot, reasonably far away from other sources of interference.

Ozy666
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Post by Ozy666 » Sat Jul 09, 2005 9:15 am

Generally you don't need to connect your CD/DVD drive to your sound card anymore. The digital sound is transported over the PCI bus.

Ozy

m0002a
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Post by m0002a » Sat Jul 09, 2005 10:02 am

Ozy666 wrote:Generally you don't need to connect your CD/DVD drive to your sound card anymore. The digital sound is transported over the PCI bus.

Ozy
Yes, I know. But it also competes for PCI bandwidth that way. I didn't pay anything for the cable, so I figured that I might as well use it.

Mar.
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Post by Mar. » Sat Jul 09, 2005 11:23 am

m0002a wrote:
Ozy666 wrote:Generally you don't need to connect your CD/DVD drive to your sound card anymore. The digital sound is transported over the PCI bus.

Ozy
Yes, I know. But it also competes for PCI bandwidth that way. I didn't pay anything for the cable, so I figured that I might as well use it.
Yes, and the PS/2 mouse connection uses an IRQ anyway, so you might as well use that instead of USB. :roll:

My point is that it doesn't really make a difference, and one way is much easier than the other.
~mar.

croddie
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Post by croddie » Sat Jul 09, 2005 12:58 pm

There's also some grounding you can do. There was a thread on this on head-fi but I didn't understand much of it.

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