Would like to get more bass out of my B&W 801 series 2 speakers

@chessie I own a pair of 801 series 2 which look just like yours. But in your room, they look small; in my room they hulk up like your JBLs (see more below). While they may be a bit insensitive, I was told on this forum that due to their relatively benign phase angle, that they were relatively easy to drive to the point that my Rogue Audio all-tube Stereo100’s (100 wpc) could ‘make them sing.’ I’ve never tried that combination, but have bi-amped them in several ways, although currently drive them with two McIntosh solid-state MC252’s bridged to mono for 500 wpc. I don’t find that giving them access to more power gives them any more volume; although it seems to help the dynamics a bit. I added a bit of low-volume subwoofer which helped their extension a little.
All of which is to say that I don’t think the amplification is your biggest problem.
I think your biggest challenge is the room, as in, it is very large, at least to me. I can’t speak to the efficacy of room treatments, but they seem to be used more for ‘trapping’ excess bass, rather than enhance it, in an effort to curb room modes.
Now, if I could put my McIntosh XRT-20’s in your space, let me assure you— you would hear the bass! Then you might need to reach for the bass traps!

Big room needs big driver(s) to move the air. Then look at your amp if they have trouble providing the power required by the driver(s) you have chosen. Not to say the 801’s can’t get the job done, but worth asking the question, in my opinion.

Neat house. You deserve the bass you need. I paid less than half what I paid for the 801’s to obtain the XRT’s as they are not as highly regarded, but boy do they deliver good, rich bass from the bottom to the top of the range (using series 2 crossover). Some say their best feature is the midrange, while the engineer was proudest of the tweeter tower. 

@chessie

You have not said how your floor is constructed but the law of action and reaction may have a bearing.  When your big driver moves forward, an equal force tries to move the cabinet back, especially if the speakers are on rollers. You need to mechanically fix the cabinet to the floor, with spikes or an equivalent, to give the big driver a steady platform to perform from.

The floor is vinyl that looks like wood on a concrete slab.

OP, Have you ever measured the SPL out of your room / speakers?  If not, try to get some measurements to determine if the bass responses were indeed lacking and, if so, how far is it from the targeted or the factory published level.  REW is free but need some training and experience.  I would suggest getting either Wiim Pro or Pro+ to do the room correction and EQ.  While going through that process, you will be getting the current measurement out of the speakers and room.

The coveat is the internal mic of iphone or androi phone may not up to task and a mic such as Umik 1 is recommended.

yags1 probably has it with the Sound Anchors stands.  Or, possibly Gaia Footers or Townshend.  So many chase around trying to fix what cannot be fixed until stability issues are addressed.  This also applies to equipment.

The Sound Anchors, Gaia or Townshend will not provide more bass, but rather better bass.  They will also clean up the mids and highs and organize the sound stage.

Oh, and yes the windows are quite reflective of sound and not in a good way.

Cheers