Subwoofer to go with new BW 804 D3

The most important thing for accurate bass sound is to deal with room modes. For that, it is better to use two smaller subwoofers rather than one big (unless all that matters is to reproduce huge explosions). Additionally, dsp room equalization like the DSpeaker Antimode 8033 will clean up low frequency response even more, and for not much money and only little effort.

+1 JL Audio
Best sub I ever owned!

I'd think that a single Fathom F112 V2 would be more than sufficient. You can always get another down the road. I'm using an 18 year old B&W ASW650 sub and last night thought to myself "awesome bass" (also have 804 d3).

I agree with the recommendation of the JL Audio e110 or e112. I'm using an e110 with my B&W N804s and it packs quite a punch.

REL all day long!