Subwoofer insight.

He is trying to say the REL subs are junk and that I have them hooked up wrong, even though I did it exactly as shown by the designer.   Obviously he knows way more than the engineers at REL.    You can tell by his mastery of language. 
https://rel.net/how-to-connect-your-rel-to-a-tube-amplifier/

https://relsupport.zendesk.com/hc/en-us/articles/115005872647-Stereo-RELs-Tuning-Guide

It is common for vacuum tube power amplifiers to have three sets of output connections. Since the REL high level connections draws no current, it is best to use it with taps intended for driving higher impedances such as 8, or even 16 ohms.

We suggest starting by connecting the RED and YELLOW “hot” wires of the REL high level cable to the 8 ohm speaker outputs. This is recommended even if your main speakers are connected to 4 ohm (or 2 ohm) outputs because the gain of RELs is designed to follow the longstanding industry practice of using 8 ohm as a standard. Selecting a lower impedance for the REL connection will result in MUCH lower output. 

Hi Ric,

I believe what Mr. ieales is trying to tell you is that REL subs are more difficult to integrate into a system than other brands of subs because they do not have variable phase adjustability. Phase in this case basically means that the output signal of the sub starts (or maybe I should say arrives at the listening position) at the exact same time as the output signal of the other speakers (including any other subs) in the system. In a single box speaker this is all controlled by the internal crossover. With a sub woofer and satellite speaker setup that crossover does not exist so that phase/time relationship between the sub and the main needs to be controlled in a different manner. One of the easiest and probably most economical ways to achieve this is by adding variable phase control to the sub amplifier.

REL's phase control allows you to vary the start of the signal in two increments where as other manufactures allow you to vary the start of the signal in as many as 360 increments.  It's kind of like using a ruler with markings at 0", 6" and 12" rather than using one that breaks down each inch into 1/32" segments.

Why REL does not include variable phase adjustability with their subs I do not know, I have a couple of guesses, but ultimately I do not know. OTOH there are a lot of very satisfied REL owners. So what does that mean? Who knows and for that matter who cares. I do know that you don't always need to measure to 1/32" to get the job done but if you can usually the end result will be better.

The bottom line is, do you like what you are hearing? If you do, that is all that matters.

MiniDSP could be employed to integrate the subs if one wanted to get more involved than a simple setup. https://www.minidsp.com/

That is a big room, you got anything smaller, you can treat without getting the partner upset? Does it have to be that room? There is no fix without room treatment of some kind, or just use part of the room, Can you use partitions? Fold out while in use and back when not. Servo bass? OB servo bass, pressures the room a whole different way.  If I had a room that big, there would be at least a 1000 lb of speakers, just for the mains and another 1000 pounds for bass units. That put it in better perspective...BIG room, BIG speakers, more work...

Regards

A lot of overly complicated, unnecessarily redundant information being spread around here.  MORE IS NOT BETTER!  Insanity may dictate otherwise, but keeping it simple makes it easier to control the Q in your listening room.  Quality, fewest connections possible and patience with the setup will go far.  REL Speakon connections are THEE best way to add a subwoofer to your system for 2 channel quality sound reproduction.  Use “LIVE” recordings to dial in the presence and atmosphere that your system can deliver.  REL has very good placement advice, but experimentation is key...corners are bad!  Mine faces front and is roughly in line with the mid driver on my main speakers.  Your room will dictate which is best.  Use bass heavy acoustic music to dial the sub in, repeating familiar tracks till you are satisfied.  It’s actually not that hard and fun to do when you have some extra time to tweak:)