Ok some history first. I have owned a pair of Proac Response One Point Five Floorstanders for about 2-3 years. Upon initial purchase I found the bass a bit boomy, not at all sharp. After experimenting for a few weeks I increased the distance from the rear wall, and added a set of Mana Soundbases and Nordost Pulsar Points under the Speakers. This had a massive effect on the bass, tightening it up perfectly so there was no tail off of on the speakers at all, just plenty of loud, tight, sharp bass and it appeared to improve the lower frequency response. Whenever mates came round they would always comment on the quality of the bass and these were experienced hifi owners. Now, having read all the good reviews of subs and having recently bought some surround sound speakers I decided to buy a sub(got to spend your money on something after all). I purchased the SVS PC Plus 25 - 31. I have been playing with this for the last five or so days trying to intergrate it with my system. I kept listening to different tracks with the sub on and off to see if I could hear the difference and virtually without fail they sounded exactly the same. The only way I could hear a difference was by turning the sub upto 2/3 volume and then that just sounded rumbly and overpowering. Hmmm I thought, that was a complete waste of £620. I started experimenting with my Denon AV Amp and set the speakers to small, crossover to 80hz and the processor to Stereo @ 80hz so no bass was being fed to the speakers and set the sub to about 10.30. Then by switching between stereo and direct(i.e. sending full bass to fronts) I could hear the difference between the sub and the speakers. Each time I switched to direct there was noticeably more bass coming through the system as the Proacs are overwhelming the SVS. Now to my point (I know I took my time). The more I listen to it the more I actually prefer it in Stereo Mode with the bass going via the sub producing less bass and the bass itself does sound even better(phew). It's just that I have bought a sub so that I can get less (although slightly better) bass out of my system Now I know that on movies I will get a response lower down the frequency range but it's pretty marginal (those Proacs already go really low with the tweaks).