Has anyone added a small subwoofer to 2 channel and been thrilled with the result?

I have Hegal H160 with Fritz's new Carbon 7 MKII speakers and recently added a modest Definitive technology subzero sub and a Paradigm crossover.. My room is about the same size as yours and the sub does make a subtle difference in filling in the bass at levels below 40 HZ. Here is how I set them up. . Connect the Hegel L and R preamp outputs to the Xover L and R low level inputs. 2. Connect the #1 subwoofer output to the input of the subwoofer. Sub output 2 doesn't support the phase control. 3. Set the subwoofer cutoff control to about 80-100 hz. 4..The phase control allows you to "synchronize" the motion of the sub with the woofer in the main speakers. Put on a recording with a prominent kick drum. Adjust the phase control so that the total amount of bass from the sub and main speaker is maximized. If the sub and speakers are very close it may not make a big difference. 5. Now you go back to the level control and fine tune that with different recordings. 6. Now go back to the cutoff control. If your speakers are small you may want to raise the frequency to 120hz. If they are large you may want to lower it to 40-60hz. It will depend on the room as well. 7. Now you can adjust the phase control again so that you blend the sub and main speakers. Don't worry about getting it perfect at first. As you play the system with more music you can fine tune it. The Hegel has great bass so you will probably notice tighter more dynamic bass than before. The H160 is broken in but will sound better if you leave it on 24/7. Enjoy

Interesting setup, Subzero with a Paradigm crossover...appreciate the input. Seems there are many ways to this so It's nice to get all the options on the table and that is a new one!   Thanks,

If you've got an existing 2 channel small speaker setup the physics makes it impossible to reproduce deep bass frequencies below around 50 Hz with any kind of useful sound pressure level simply because those small drivers can't move the volume of air necessary so a subwoofer is a good bet.  But you run into the issue of crossover frequency and ensuring correct phase between the satellite speakers and the subwoofer in the crossover frequency range.  Try to get a subwoofer with a built in crossover i.e. one that you connect the 2 channel small stereo speakers into and then the subwoofer to the amplifier.  This will ensure correct phase and crossover.  Adjust the subwoofer level for a well balanced sound, maybe just a little extra.  You may be pleasantly surprised how much bass content you've been missing in your music.

No.  But only in my trick I am using a box with boss 10 inch cheap driver and is not too bad.  It is connected to 1 600 watt Alpine amp.  The model before last.  My theater is the same size as your room and running 2 2000 watt dual 18" SRX cabinet and I am quite pleased with the performance.  For the truck I havent got around to installing the second 10" sub and amp configuration.  I just need a couple hours to wire it in.

+1 on REL. The best decision I made was to add a REL T5i sub to my system (room size 12x16 feet). I was on the verge of upgrading my Dynaudio Contour 20 bookies to the bigger Contour 30 floorstanders due to a slight lack of bass (noticeable with jazz and electronica). I realized upon auditioning the Contour 30’s that I preferred the imaging of the smaller Contour 20’s and adding a sub would be a more affordable option as well. Turned out to be the best decision as the C30’s would have been overkill due to my room size. Once I got the REL dialed in it brought my system to another level. Hope this helps!