You're one of the good guys and I hate doing this but I also hate misinformation online (I think we both know how much trouble it can cause).
I tried to make some graphs in MS paint to show what I mean but failed and I can't overlay graphs in the software I use
. I wanted to show that the midrange always stays at the same level when the crossover stays the same - but the bass can only be linear with one enclosure size and tuning frequency (with that particular crossover). That is a fact, not an opinion. If you go for an extended bass shelf (bigger box) without adjustments to the crossover, the bass, midbass and possible lower midrange will be lacking. If you raise the tuning frequency to try to compensate, you will have a peak at the tuning frequency (wonky low frequency response), so it kind of compensates but you still have a midbass and lower mid that's lacking. (This is all assuming you have a speaker with a perfectly flat frequency response to start with)
This isn't an opinion, this is a fact, that can be backed up with data (if I could work out how to do it).
I don't dispute this, but respectfully point out that
some of the most desirable vintage speakers of all time, and the monitors which some of the most respected ears in the business chose to use, used these drivers and the same crossover in a variety of cabinets, volumes and port tunings.
So, the effect of cabinet size must be amenable to workarounds, and the driver/crossover not particularly susceptible to having its plusses buggered up.
There are level controls on the crossovers from golds onward, BTW, Treble and Energy IIRC.
Tannoy wisdom is that they work better in some cabinets than others...there is a hierarchy, with rectangular Lancasters supposedly not getting anything near the best out of the drivers, and the sweet spot being Yorks, particularly corner Yorks. Look at what fetches the money on ebay.
I've owned a few different Tannoys over the years, including Autos, and the ones I prefer, which I still have, are 12"MG in 200l cabs with silver crossovers.
I think those fairly high efficiency drivers with large cones, because a large area of their wavefront is directly driven, with smaller cone movement, rather than propagated from a fairly small source, are doing something a bit different, and are more subjectively more immune to cabinet and port effects than speakers with smaller drivers with big excursions.Big Altecs are the same - way less fussy about cabinets than you may think. For years Tannoy used to sell Lancasters with the wrong size port, or the port blocked off...still sounded pretty good. They could do that because the driver and crossover is outstanding, one of the best transducers made to date.
I know you have the maths to back it up, but I've heard a lot of Tannoy drivers in a wide variety of cabs, and I'd say they all sound good - some special - but the bigger the cab the free-er and more effortless they sound, though the Autos could boom unless they were loaded with Reds. Though that kind of follows, as they were designed for silvers, which are more or less reds. I will say though that I regard the Tannoy horn designs as being less successful than the ported ones. Perhaps the mid-shy Tannoy you referenced upthread was a horn design?
I'll just finish up with an anecdote....I had a pair of HPD 385s lying around, and I was at the car boot and there were an empty pair of Maplin AC PA carpet covered cabs (for 1 x 15 and a piezo horn) on a stall for a fiver...bought them, took them home, converted the horn cut out to a guestimate port, screwed the crossovers in internally, drivers a direct fit...all done by mid afternoon the same day. Sound bloody excellent. No boom and subjectively flat. Come and hear em if you like!
Then there's the Lockwood design...
Anyway, I'll stop now. I'm happy to continue the conversation if you listen to some Tannoys - and Altecs - and familiarise yourself with the sound, and what they do. At the moment I'm reminded of the scientist who say a bee can't fly...
