Upgrade to B&W 804 D4 Speakers

The 804s aren’t a great match for your tube amp (or most tube amps) as it has both difficult impedance drops and phase angles even well above 80Hz, so even if you cross the subs around there your amp will be working hard to drive the speakers properly.  From Stereophile measurements section…

The solid trace in fig.1 indicates that the impedance magnitude, measured with Dayton Audio's DATS v2 system, lies between 3 and 6 ohms in the upper bass and midrange, with a minimum value of 2.55 ohms between 121Hz and 131Hz. The electrical phase angle (dashed trace) is occasionally high; for example, there is a current-hungry combination of 3.7 ohms magnitude and –55° phase angle at 87Hz. The effective resistance, or EPDR (footnote 1), drops below 2 ohms between 22Hz and 33Hz, 62Hz and 116Hz, and 663Hz and 886Hz. The minimum EPDR is 1 ohm from 88Hz to 110Hz and 1.6 ohms at 886Hz. The 804 D4 must be used with amplifiers that don't have problems driving 2 ohms.
 

In that price range I’d highly recommend the Joseph Audio Perspective 2 that is much more amp friendly, and frankly when I compared the smaller Pulsars (original version) to the 805 D3 I found them superior in almost every way — better imaging, more expanded 3D/holographic soundstage, just as detailed but more balanced, natural, and overall just more musical sounding, and they pull off a superior disappearing act as well.  I’d expect similar between the Perspectives and 804s.  The ProAc D48 or K3, Usher ML802, and the Vandersteen Treo are others well worth a look in that price range that’d also be more suitable for your amp.  Just my $0.02 FWIW. 

I listened to a pair at my local Best Buy a couple of months ago.  They were connected to some SS integrated amp with 100 wpc - don't remember which brand.. 

They sounded slightly metallic to me, but it was actually kind of pretty pleasant to my ears.  Surprisingly, the bass was so-so - I expected more.  I listened to some Pink Floyd songs that I'm quite familiar with.

I also think that a SS amp might be a better match with these.

You have a lot of choices at 16K. B&W are very good value. Dynamic too. Maybe not the most musical.

I agree with comments, with a budget of $16k you can get a lot of speakers.

Canuck Audio Mart is chock full of speakers, some barely used, usually much lower price than new. 

I personally try to buy nothing new. Most stereo shops also have lots of used gear you can audition.

B&W seem to be power hungry, and not a good match for tube amps.  

Ask Chatgpt about amps to drive B&W, see what it says?

In that price range, you might consider Fyne Audio F-703s or F-702SPs.  I have the F-702 ( not SP model) with two Rythmik subs with a Rogue RP-7 preamp and Odyssey Kismet mono-bloc solid state amp.  Wonder music presentation!