Waiting on 802D3 to arrive -- Will I need a sub?


It's a rainy gray Sunday afternoon here in Atlanta today. I probably have better things to do but I've spent hours reading and researching trying to ascertain if I will need a subwoofer(s) once my B&W 802D3 arrive here in another week or so.

I can't decide and so I've decided to try posting here and crowdsource an answer, ha ha!

My goal is to create a system that will allow me to listen to 2-channel music for hours on end without fatigue.  The room is my living room and is a quasi open floorplan. It is around 24 feet long by 18 feet wide.  There are 10ft ceilings with an open stairwell back behind the seating position and an opening to my dining room that adds another 400 square feet or so of floor space.

Previously I've had B&W 804D2 towers with two B&W ASWCM10 powered subs.  I've sold the towers and the subs and am waiting on 802D3 to arrive as mentioned above.  The 804D2 absolutely had to have the subs.  The bass just wasn't there without them unless I really cranked the volume up.

So as I sit here I'm wondering if I made a mistake in selling my subs already.  With the 802's will I miss them or will those guys have me covered for 2 channel listening?

If it's likely that I will still need a sub (or 2) what do you guys think would be a good match to the 802D3?

Here is the rest of my equipment in case its helpful in offering an opinion:

Preamp:

·     PS Audio BHK Signature Preamplifier

Amplifiers:

·     Qty. 2: PassLabs XA60.8 Monoblocks

Inputs:

·     PS Audio DirectStream Junior (DAC)

·     VPI Traveler 2

·     Audio Technica AT33EV Phonograph Cartridge

·     Apple TV 4K 

Power:

·     Qty. 2: PS Audio P5 Power Plant

 Other:

·     Pro-Ject Tube Box S Phono PreAmplifier

 Speakers:

·     Bowers-Wilkins 802D3


Thanks!
Bryce
brycethomason
I want to just thank everyone for all the input and advice.  I've thoroughly enjoyed hearing folks from both camps. You all are certainly experts with well thought out opinions.  The one thing that is truly clear is that at the end of the days it will be left in the 'ears' of the beholder.  The 802d3s arrive on Tuesday of next week, so I'll know what suits my ears soon enough. 

The deal to sell my two B&W ASWCM10 (not the cm2 mind you) subs fell through, so I actually still have them.  I'll just hold on to them so I can do some a/b testing with them.  I don't know if they will do justice to the towers the way a b&W flagship sub like a DB-1D would but at least I'll have them to make that call here shortly for myself.

Again, I've enjoyed the hell out of this conversation and send a heartfelt thanks out for some seriously great engagement on the topic from this community.  Thanks for the help!
bdp24: "The bottom octave is a bitch to reproduce, and very, VERY few speakers are up to the task."

I would amend that sentence: "The bottom octave is a bitch to reproduce, and very, very few ROOMS are up to the task."

There is that too, dualmarantz! To find the locations of the resonant modes in your room (via the calculators on the net; modes are generally along all the wall/floor/ceiling intersections, and at the 1/2, 1/3, 1/4 divisions of the length, width, and height of the room), and avoid those locations for your equipment rack, speakers, subs, and listening chair, is a good start. If you can afford them, install "true" bass traps (not those flat pieces of Owens Corning 703 wrapped in cloth that some companies market as bass traps) in those mode locations, to soak up the standing waves. OB subs are a way to excite fewer of those modes to begin with, but most people don’t want to go there.
The answer to your question, in my opinion, is not always do I hear enough bass to satisfy myself? Bass frequencies suck up a lot of amp power which means that amp power isn’t there for the higher frequencies if it is need. Drawing great amounts of amp power also strains the amplifier. Typically amps. put out considerably less that they are capable of and that is desirable so as to preserve amp reserves when the program material demands it (head room, etc.). This has nothing to do with being a "bass face"- very few full range speakers can produce bass as well and as accurately as (a) dedicated subwoofer(s)and if you sacrifice amp power to produce bass you are likely to also be affecting the production of higher frequencies. Hopefully this will be helpful.
The 804D2 is 3db down @ 38hz,  The 804D3 is 3db down @ 17hz.  Unless you place them where a room causes a suck out effect,  there is no reason to add a sub to this speaker. 
If you do add a sub,  you will be ADDING to these frequencies of where ever you cross,  say 40 hz and down. Effectively,  you will be causing a hump in the bass region from the crossover point and down..  Not my cup of tea