Heard the B&W N804d3s ...

B&W have quite a variety in sound between models and over the years. I don't think you can simply think of them progressing linearly with minor tweaks but they do produce good quality consistently but often changes are different cosmetics and flavours.

In that sense - stick to what you have!!!!

@shadorne ... that's exactly what I intend to do for now. I just want a little "oomph" in the bottom end, that's all. I really like the sound of the N804s. The 804d3s are no slouches, trust me, and they are a bit of a different flavor; however, to me, that flavor simply doesn't appear to justify $9 grand worth of ice cream.

" The old aluminium tweeters of the Nautilus line you own can sound harsh. "

For me, listening to B&W aluminum tweeters is like cleaning your ears with an icepick. 

" Audio is not based on what you read in paid magazines, but is based on the results you get during shootouts and tests. They give you the real and True information you want and need."

I stopped reading reviews years ago. You really don't need them. I think most audiophiles are afraid to make a decision on their own. I understand, because a mistake can cost a lot of money, but if you take the time and learn to do it yourself, you get much better results.    

I have some old B&W 602's in my office system.  I have tried different amps and pre's with them.  I am currently running 2 Carver 65x2 amps that I just had serviced and recapped, one to each speaker biamped.  They sound great.

My local Best Buy had a pair of open box CM5's that they gave me a great price on.  I brought them home and they were very slightly better.  They had a bit better sound stage and clarity, but the difference was minor. I am also a huge believer in diminishing returns and I didn't think it was a $900 upgrade.

I have been looking for a replacement bookshelf, but haven't been able to decide what to get.  I have demoed speakers that are much more expensive and running on better gear and I don't think they sound as good as what I have.  I agree that you need to demo in your own space.

A good sub should sound good with the 804's and actually will do more to the perceived sound than just add lower bass.  The 804's are basically very revealing older monitors with "built-in stands", as opposed to full range speakers.  I agree with other posts that room size will limit lowest bass you can experience in your listening room (but not necessarily down the hall!). For this reason I would shoot for quality of bass rather than trying to buy down your Hz.

Try the Rythmik and see how that works. For the quality of the rest of your system, you might be happier with the F12. Another option for a small room is the B&W PV1D or the PSB Subseries 450.  Anyway you cut it, good bass is expensive.

kn