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

This in combination with your other post clearly points to a room problem.  B&W 802 D diamonds measure flat down to about 33 Hz in an anechoic chamber.  Your room/speaker interaction is the root cause of your problems.  See my post to your first question.

@billstevenson +1 Where the listening spot is affects perception of bass. Move the speakers closer to or right up against the wall. You probably have them too far out into the room.

well physics of sound in room is what is happening. you're having what is called exciting of room modes and room nulls. those are not something you can escape so maybe the SBIR related dips are a lot in your room. you can only know this by sweeping sine wave from 20Hz to 20kHz or using a measurement mic and Room EQ Wizard to take RTA of your room form your seated position. There should be big dips @onehorsepony 

I have my speakers out from the front wall 24", 8' apart and 4' from the side walls. Soundstage is very 3-dimensional. When I push the speakers closer to the front wall, say 6", the bass is improved and the tweeter energy sounds toned down.

However, I do lose the soundstage.

Someone, in one of my posts insisted that my preamp and amplifiers are not a good match for my speakers. Can anyone elaborate as to why?

@onehorsepony unfortunately as you hear for yourself in your space... Speaker/room synergy is more important than any amp you buy. Bass nulls don't just go away because you got a new amp. this is how people here get stuck in a cycle of purchasing things because someone told them it will solve something without actually addressing the physics of why there are nulls in the bass region in rooms. What you need is a measurement mic and Room EQ Wizard, corner bass traps and a subwoofer

@kofibaffour  +1 Room EQ Wizard

The first thing to do if you want to fix a problem, is to determine exactly what the problem is.

What is your room size and what amp are you using?

What do you have for amp,preamp  as well as loudspeaker cables  and power cords  each one part of the sum of the whole  can has a sizable impact 

if you would state what  you have  it can be determined if it is sufficient 

I have 40+ years in audio , and owned an Audio store .

first thing  how big is your room ?  How har are speakers from the wall ?

the closer to the wall more bass reinforcement   All of the above count ,

another big thing since I have rebuilt the important Xovers 

if your speaker is over 10-15 years old the Capacitors dry out  which would cause Detail and or low frequency response  to be greatly effected !!

Bass nulls and bass booms are caused by room nodes. These are created by the shape of your room and the position of your speakers within that room. Changing speakers will do nothing. Room treatments will not help a great deal as bass  nodes require fundamental changes in the room shape to be dealt with. Bass boom can be solved by DSP but bass nulls, as you have, cannot,  as it is not good practice to boost frequencies a lot with DSP as it can lead to clipping. However, you could try supplementing the bass with subs. Oh, I’m sure you have done this, but check the previous owner did not leave any foam plugs in the ports - B&W supply these to help temper bass boom issues and they are often left in there when selling. Alternatively can you fire your speakers down the room the other way and move the listening position ?  That will fundamentally alter the bass nodes  

With regard to your other issue of too much glare in the top end, unlike bass issues these are easy to treat with room tweaks: rugs, curtains, simple absorber panels at reflection points etc. 

What is your room size and what amp are you using?

Approximately 16 x 25 with 6 1/2-foot acoustic ceiling panels

PSaudio BHK preamp and BHK 300 monoblocks

 unfortunately as you hear for yourself in your space... Speaker/room synergy is more important than any amp you buy.

Well to be honest, replacing my Bryston BP26 and Classe CAM-200's with the PSaudio BHK preamp and BNK 300's did make quite an improvement.

The soundstage became larger, much better separation between instruments and just an overall fuller sound.

It seems to me that you can test the Room Null theory by walking around the room. If there are nulls, there should also be points of boost, where the bass is accentuated. As is pointed out above, there isn’t much you can do about how the speakers perform in the room without major re-orientation. For instance, if they are on the 25’ wall firing in at the 16’ ft wall, put them on the 16’ wall and fire them at the 25’ wall. 
 

The reason subwoofers help is that you can move them around the room. Put the subwoofer in the listening position and move around the room until the bass is strong. Then put the subwoofer in the place where you are standing and the bass will sound strong in the listening position. The subwoofer, by being in a different position in the room, counteracts the room modes generated by your main speakers. 
 

Some people find they need, two, three, or four subs in an ‘array’ to fix the problem you are having. 
 

I responded to a quiz recently, is it the room, the speakers, or the amp that makes the most difference to sound quality; 62% responded that it was the room. It truly is a limiting factor, or, shall we say, the biggest opportunity to improve sound quality. 
 

Good Luck

Good luck is correct. These speakers weigh in at over 100lbs per unit. Although they have casters on the bottom, they are ineffective once they sink into the rug

Acknowledged. I have the 801’s which have a single Woofer. No one said it would be easy. The gear purchase is often only the beginning of the journey. 
 

I remember one presentation from Dyne Audio (I think) that mentioned a typical bass frequency sound wave was 30’ in length which means that unless your room is at least 30’ deep, the sound wave ‘high’ will bounce back and either reinforce the succeeding bass note ‘highs’ or level (nullify) them. The subwoofer’high’s and ‘lows’ are frequency and distance sensitive. Avoid offending bass frequencies, no nullification; move to a different distance from the speaker (or the wall), and again, the nulls disappear. It is these facts that any solution must address. 
 

Bass traps, ‘catch’ the rebound signal off the back wall, and solve the null problem by preventing the interaction. Seems a cleaner solution to me, but I listen near field at the moment, so I’m not experiencing what you are right now. 
 

Again, Good Luck. 

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

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’.

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

I'd love to read some reviews of my electronics where they say that they tend to be bright. I was under the assumption that they were more on the warmer side since they had tubes on the input stages.

Also, some rooms do have 6 1/2 ceilings. In my case it is a finished basement.

BHK Preamp Review

The sound of the BHK Signature was incredibly smooth. Everything I played through it had a palpable presence that washed over me like a slowly moving stream -- no pressure, no haste, no fatigue, just music. Voices emanated tangibly from the soundstage, easy to pinpoint in space

OP, FWIW, I took a few moments to read some of the reviews on your amp and pre-amp. In the reviews I read they were given high marks, and a reader might logically assume that they might be an excellent match. Since I haven’t heard them, I cannot agree or disagree.  But IME synergy between electronics and speakers is critical. Whether or not this synergy exists cannot be determined until you have maximized the speaker/listening position for your speakers. Obviously if the electronics’ are not a potential problem there are only two other options, the speakers themselves or (most likely) how you have set them up. How you approach this problems solution is up to you. 

Good luck.

jeffbij had some great advice.  I am sure that either your chair or those speakers are in a bass-null area of the room, there's really no other explanation.