the effectiveness of these devices has been disputed for some time now. Check this out...
http://forum.audiogon.com/cgi-bin/frr.pl?raccs&1130502163&openfrom&1&4#1
http://forum.audiogon.com/cgi-bin/frr.pl?raccs&1130502163&openfrom&1&4#1
whats the difference?