Where is the bass on my B&W 802d speakers?

FWIW jasonbourne71 makes a much- overlooked observation, that is the importance of the location of the listening position can greatly affect the sound you hear from your speakers (although I disagree with his suggestions for speaker placement). 

The absence of bass information can direct your attention to the higher frequencies and making them sound brighter than they would if your bass FR were neutral or slightly boosted. 

Your listening position could be in a bass null and moving it forward or backward could possibly solve both of your audio problems if you put it in in a neutral zone or a small node. Ditto for moving your speakers out further from the wall than you presently have them. You might just find a bass node to solve you bass issue and actually improve your treble response and bass clarity.

I know zip about your electronics beyond a perception that I gained from reviews that they might be, sound wise, less than ’warm’ and exacerbate problems when connected to speakers which might also be less than ’warm’. IME brightness can often occur from this syndrome as manufacturers are focused on maximizing imaging potential by over emphasizing the mids thru high frequencies. Folks caught up in this tend to buy separate components with similar design goals and end up with a bright system. 

FWIW, if your room dimensions as listed mean you have a 6 1/2ft ceiling this might in and of itself create problems. I’ve never heard a room with so low a ceiling, but I could imagine that it would give you some increase in first reflections and tilt up your highs. I have no ready solutions suggestions for that. 

FWIW, using an equalizer as a tool if not a permanent component might be helpful to find the frequencies which need to be changed to get you where you want to go, sonically speaking.

Get a couple of subs as that can really damp room nodes, move the main speakers around, move the whole rig into a better space.

Have you checked the basics? Have they always been low on bass, or is it a new thing? Has anything changed?

Being in a NULL is a real thing, and almost nothing will fix that other than moving the seating spot, or speakers. 

Just having gone through this myself with other speakers, it drove me nuts for months. Turns out, I swapped polarity (Rch) from my sub to main speaker. It sucked the bass out of the room. Thought there was an issue with my sub, until I setup my SPL meter, started a 40hz tone, then panned L-R on my balance. Went from good bass, little bass, no bass.

Felt like a dumb A$$, but was happy it was such an easy fix. 

I agree with approximate speaker placement. Have you tried using SPL meter and Stereophile test CD or similar with test tones? You  need to find out whether you get a response down to 33 Hz or somewhere near that vicinity at your listening position. If this test fails, then you should try changing the speaker placement as suggested by @jasonbourne71. I would do these steps before you start swapping electronics.

One other thing to try...  Most people will setup speakers to be symetrical in a room.  i.e. same distance from the back wall and from the side walls.  And if your room is symetrical, then you can get a lot of equally timed reflections coming together that can create the nodes.  Try moving the both speakers 1 foot off center (both right or both to the left) so they are no longer symetrical to the room.  Now your reflections will be misaligned and mistimed and it can scramble the nodes.

I did that with a set of Martin Logan electrostatics where my "best" seating position was right in the middle of a measurable bass node.  The shift elimated the bass node.

... just a thought...

- Jeff