Best subwoofer for Quad 988?

I get excellent results with a pair of Rega vulcans(the drivers are small so this means speed).They are based on the REL subwoofers set up(speakon connectors),no roll off,the main speaker and the subs work together.This may sound strange,but I believe in using british subs with british speakers.Both the Rega and the Rel are UK designed.Look them up.They are fast and you will not know you have subs in your listening room,just the bass in the music.I have used various Quads since 1985.I can talk source and electronics,but,thats on a different day.

TBI! Read the Stereo Times review by Dan Dzuban. He owns a pair of Quad 989s. http://stereotimes.com/speak112204.shtm

I'm running a TBI Magellan VI with a pair of 4 way full range electrostatics and the transistion is seamless.

If your friend is happy with the Quad's volume as it is, then any REL would be perfect. Otherwise spend a little more for a pair of Velodyne DD-10s or 12s.

Tom,
I would recommend the Martin Logan Depth which is made to work in conjunction with ES speakers like your Quads. Very fast and musical sub that has three eight inch woofers. I have also used and liked B & W ASW 750 and ASW 675 which were good with two channel music.
Regards,
JWALKER

The best subwoofer for the quad 988 is TBI. Read this review. http://www.videohifi.com/16_TBI_ENG.htm and others from the site.