My home cinema/music listening kit consists of amp=DENON 3802, centre=KEF Model 100, L/R=KEF Q5 and surrounds=KEF Eggs set up in my 13' x 24' lounge/diner partitioned by a 6' wide archway at 12' from lounge end. I decided to wonder in to my local dealer to see if he could recommend a decent sub that would offer a significant improvement to both my music and LFE listening pleasure. I find that I do get some nice rumbles out of the Q5 speakers in home cinema use but I'm wondering if I'm still missing something and music sounds very thin in surround mode - the centre cuts off @ 70Hz and the Q5s don't seem to take over seemlessly very well below that (the amp is configured to centre=small). I was considering REL stampede but that's the max I would want to spend. The dealer suggested the M&K KX10, so I've booked a demo in a few days time, when it's back from loan. I've been looking for advice on the forum and comparing the specs on paper and I'm not feeling confident about this recommendation - but then I haven't listened to it yet. The KEF Q5's paper spec says it has a lower frequency response of 39Hz +/-3db and the M&K spec for the sub says 35Hz @ -3dB. So, I'm thinking why pay so much money to gain an extra 4Hz over what I've already got?! Also, I want to check the frequency response of my set-up. Thanks to this forum, I found "SigJenny" PC software but what microphone should I use and how do I get a frequency calibration for it? I have a £30-ish (digital) SPL meter but no frequency calibration details. Thanks for any help or alternative suggestions.