Assuming that the sub is placed in the appropriate location (see “sub crawl” on youtube): you would gain some low bass extension, generally improved bass, and possibly improved clarity from your stereo speakers. Bass is not always a strtaightforward subject; you may wish to consult Paul’s excellent book The Audiophile’s Guide: The Stereo. Note that the room, room treatments, and setup are as important as any equipment we purchase. Good luck, it’s a fun process!
Heads-up as REL has a subwoofer to speaker pairing guide on line. The for the B&W 802 the S/812 is recommended for a medium sized room. The 802D is not listed in the guide, butte S/812 is a fine subwoofer.
DIY speakers with very good SEAS drivers. The further they are from the wall (now 3 feet to baffle) the better the sound stage but the bass really drops off due to room nodes.
I had a DIY sub but could not integrate it very well so I sold it.
Now using REL S/510 sub in the only available corner and it’s a keeper. Since the room is not large (14.75 by 15.5 feet) the diagonal sub alignment provides the lowest bass response in the room, but I had to build a floor to ceiling bass trap on the opposite corner. We do a lot of listening when up one floor level and that extra length of space provides very deep and clean bass upstairs. I optimized the REL sub with a very good AC cable, plugged it into my P12 regenerator and made a better high level cable. The extra bass from low 20s to mid 50s Hz improves music immensely, including better vocals and more sense of space in the sound stage. RELs claims on what their subs can do are true!
Just bought a UMIK-1 microphone and now learning to use the RoomEqWizard (REW) software. It shows very well how the sub is integrating with the main speakers and room nodes.
I have two T9xs. I had the 812s but that was overkill. And if you want overkill, the JL F113 is a must! I loved that thing but it was not as musical as the Rel line in imho. Subs fill out the low end in my book, not so much as “add” low end. Once everything is tuned in, listen to Thanks to You/ Boz Scaggs then turn the sub(s) off and listen again. You’ll never go back…
I added a Rel 212/SX to compliment my Klipsch RP-280 2 channel system in December 2022. WOW! Love the addition. I previously had an SVS PB16 in this system, but moved to the theater room in 2018 and really missed the lower range the SVS single sub provided. The Rel is much better than the SVS in a two channel stereo system while the SVS is fantastic in the theater room.
The Rel 212 SX is a two active driver system with an additional passive driver. IF your budget allows, consider the Rel subs. This made a substantial improvement to my existing set up.
This is another issue I’m having with the CAM200s. Probably for another thread but I’ll describe it here as well. When I had my Bryston preamp, if you envision the volume knob from 6 clockface, full volume was between 7 and 8 clockface, very small volume range.
The BHK preamp, full volume is between 25 and 30.
I hear Paul say in a video that for maximum bass the volume should be operating around 3/4 within it’s range.
I currently have 3 subs in the room, with the subs off, a good solo piano recording sounded like a good piano recording + some. With the subs on, all the emotional content and flow, timing, and air(high registers) gets amplified and it sounded Maurizio Pollini is in my room humming alone with his master craft.
Draw back is you really need to spend time to tune the subs to match the room and speaker, when you change something major in your gear, chances are, you’ll have to retune the subs again.