Asus Xonar's EMI shield, DIY EMI 4 Revolution 7.1 SNR?

Asus Xonar has not a heatsink but an farrady cage EMI shield to help screen out noise and improve its SNR. Some creative x-fi also has the same feature.
Asus claims a SNR-118 dBA, with something like a 3-4 SNR improvement due to EMI shielding.

I have an older m-audio revolution 7.1 -- should I build a EMI shield if I want to improve its SNR ratio and if so, how do I do this without short-circuiting the wires? If it is risky I won't do it, but if it is risk-free, inexpensive, quick, and improves SNR by 3-4 dBA it might be worth doing. Oh I am using analog logitech speakers 5.1

I'm not sure how effective they actually are, hasn't Asus stopped putting them on its newer cards? Some people place the card inside a magnetically shielded bag like you gets with most computer equipment. The most interesting solution appears to be ERS paper. See here:

http://www.head-fi.org/forums/f46/hotro ... 6k-226975/

thanks for the link. I don't want to risk damaging my own card. I'm not sure hwo effective they are, but at newegg and other vendors, asus xonar and new offerings from creative x-fi fatality use shielding.