@Kind of Blue I still use a pair of Tannoy 12" gold dual concentric speakers in sealed Chatsworth enclosures, not really hifi as they form the front right and left to my surround sound and are fed from a decent Pioneer AV integrated amp however these were made in 1969.
As I said though not hifi as the bass extension comes from a REL sub, so boom rather than bass!
I know the Tannoy Gold Duel Concentric, very efficient. They would allow valve amps to reach significant levels. Years ago I did a lot of reading around the drive units used by Tannoy they also used 15" duel concentric. I was considering making a set of speakers that incorporated them. My speakers also have 12" bass units. Mine are PMC MB1 identical to MB2 and MB3 with a few subtle differences, actually the MB3 uses exactly the same drive units as the MB1. MB stands for Medium Box. I waited for years to buy used BB5s Big Box but they never came up used at less than astronomic prices. BB5 can cost £26,000 for passive, the actives cost significantly more. The MBs use the same tweeter and mid range as the BB5 but only have 12" bass, they go down to 20 Htz The BB5 uses 15" bass and also has a far larger Transmission tunnel, going down to 16Htz. I would sell my sole for a pair of BB5 in any form but I have not won the pools. I do not do them.
A new set of MB3 even commercial versions start at £11, 000 plus discounted the domestic versions now £18,000. Silly prices. Chatsworths will also be very expensive, I am quite sure.
I use ATC pre-amp and power-amp only 150W. I was a little put out to find that ATC did a 300W version or I would have bought that. There is no substitute for power. I would really like to convert mine to active or buy a very much more powerful power amp. 600w perhaps Bryston but I shall probably be left with what I have. I was born before the dinosaurs, so I am constantly informed
so after sorting the Truck out, that will be it I guess... As you will know its not the absolute volume but the reserves of available power allowing instant response. Very much like large power units in vehicles a big good one is better than a little good one sort of thing. I heard a pair of BB5 being actively driven by what must have been well over 1000W per channel and they where the absolute Dog Bollocks. They are used by many recording studios and the BBC.
Any way we can have our pipe dreams can we not. One never knows
Did it take you some time to adjust the Rel Sub or does it have some automatic internal computer levelling? I would not feel it is not hi fi, it depends on how it integrates and weather it is over blown accurate and so on. There is an awful lot of rubbish spoken in the World of Hi fidelity sound just as in the car industry. It is whether we are happy and what we can afford and compromise against living in the real world with all the other pressures of life tugging and pulling. Not some joker from a Hi-Fi or Car Mag tells us. They may not be unbiased and and I have been informed nor would some pass scrutiny so far as impartiality and how many of them have science degree or or have music degree either.. They have to sell magazines and make a living and advertising is probably their greatest source of income just like for News Papers.
By the way I listened to your list of music and took some notes if i can read them as I was on London Pride last night I will give a comment latter, someone else wants the web at the moment but I can say that I generally like whet I played.
PPS you could make up some damping panels from rock wool insulation covered in cloth. It would cut down on any excessive boom.