after 30 days you don't like them you can return them for a full purchase price refund. The new Emotiva X-Ref 10 subwoofer I think would mate well with the airmotiv speakers.

http://emotivapro.com/products/powered_monitors/airmotiv5.php

http://emotiva.com/xref_sub10.shtm

Unless you use a CRT television or monitor, magnetic shielding is unnecessary.