Jay,
not surprised you had such bad luck with REL, they make two kinds of subs, HT ones which suck and Music ones which blow, hehe.

But seriously, the Q series are absolute distortion mongers, whilst the ST series are a nightmare to integrate with anything more than two speakers. I've been doing some serious research into the behaviour of downward firing subwoofers and have come to the conclusion that whatever gains you get from pressure loading the driver against the floor are wholly negated by the appalling behaviour in the crossover region.
It is the crossover that is the most important part of integrating a subwoofer with 'small' speakers and getting it wrong sounds exactly like what you had - zero midrange.

RELs are great for stereo applications where the built in crossover is a benefit, where you have an incredibly sophisticated and well implemented digital crossover such as in Meridian processors they're a liability.

Mark
G68, baby Genelecs, Humax Foxsat, Oppo+Vanity93, Toshiba HD-A35, Pioneer CLD-925 + Meridian 519, various other random bits and bobs
Got a black G08.2 you want to sell?