ToTo Man
the band not the dog
A few months ago I made the difficult decision to sell my Tannoy Lockwood Majors (fitted with MG15s) and revert to my Tannoy Edinburghs which I had ‘retired’ several years earlier. The Lockwoods are of great pedigree, however I just could not get on with them in my acoustically treated but modestly sized 4.2m x 3.8m x 3.25m room unless I applied Dirac room correction across the full frequency spectrum to smooth out the response. With correction applied, they were superb, probably the best sounding speakers I’ve owned, and in hindsight I was crazy to sell them. However, unfortunately I listen with my eyes almost as much as my ears, and I was very frustrated that I had an aesthetically beautiful (to my tastes at least!) pair of Edinburghs that I hadn’t enjoyed for years. I was also given an ultimatum to reduce the number of “wardrobe-sized speakers” in the house, so sadly the Lockwoods had to go…
I original retired the Edinburghs due to being unsatisfied with their bass output. Over time the surround of the 3149 driver stiffens and consequently raises the Fs significantly, necessitating either a re-cone or a long and arduous process of removing the incumbent doping compound and applying new doping compound. I chose a 3rd and perhaps more radical option; to buy a pair of XXLS400 subwoofers to fill in the missing lows! Once balanced with Dirac, this turned out to be one of the smartest moves I have made. I was now experiencing bass with a smoothness, speed and extension I hadn’t had with any of my previous loudspeakers including the DSP’d Lockwoods. However, the more I listened to the Edinburghs, the more I noticed other colourations, particularly in the mids around the crossover frequency. No problem I thought, I can fix this by applying Dirac to the mids and highs as well as the bass. To a large extent I was right; with full spectrum DSP applied the Edinburghs became much more neutral and transparent in the mids and highs, and the soundstage opened up superbly. However at higher SPLs, there was still an audible harshness that made extended listening quite fatiguing, and no matter how hard I tried I just couldn’t learn to love the sound.
I’m no expert, but as far as factory-built cabinets go, the Edinburgh enclosure seems very well made, and so with the right driver and crossover, I figured it must have the potential to be a stellar loudspeaker. Which got me thinking, what if I replaced the stock 3149 driver with vintage DC driver and crossover? After consulting a couple of Tannoy experts I was advised that the Monitor Gold 15 or HPD 385 would be ideal for the 200L distributed-ported Edinburgh enclosure. However, as a woodworking novice, I was less than enthusiastic about irreversibly enlarging the cutout in the beautiful cork baffle to accommodate a 15-inch driver, so I turned my attention to 12-inch units. After a very disappointing experience with a pair of recently serviced and re-foamed HPD 315s which turned out to be an extremely poor left/right sonic match, I elected to use a pair of Monitor Gold 12s which I'd stored away for a rainy day. Having never measured these, it came as a wonderful surprise to find them matched to ±1dB across most of the range. They are also the flattest of all the Tannoy drivers I have measured above 1kHz. Things looked very promising!
I was a fool to think that it would be a simple process of unbolting the 3149 driver and bolting in the MG12, in fact it couldn’t have been further from the truth! This is what I learned during the process: (1) The bolt holes of the two units don’t line up, so new holes need to be drilled for the MG12. (2) The rear basket of the MG12 is larger in diameter than the 3149, so the baffle cutout needs to be enlarged. (3) MGs are clearly not designed to be front-mounted, as the bolt-holes literally need to be drilled 1mm away from the edge of the cutout, which means if you make the cutout fractionally too big or you slip the drill then it’s game over. (4) The drill holes are so close to the edge of the cutout that conventional tee-nuts are extremely difficult to use to provide a thread for the bolt, so I instead inserted the bolts from the rear and screwed on conventional nuts from the front after the driver had been mounted on the bolts, - not as easy as it sounds!
Two weeks of hard graft and I now have one Edinburgh cabinet fitted with an MG12 driver and its associated LSU crossover. From early listening tests and measurements, I am chomping at the bit to get the other one done! I am very impressed with the sound; it’s transparent, clear, detailed but also punchy and has excellent depth and sense of scale. I’m actually surprised by the quantity of bass; it sits between my sealed Lancaster MG15 (which are too lean IMO) and the Lockwood Major MG15 (which were overbearing IMO) but is better controlled with more speed and less overhang. I don’t understand much about T/S parameters, my ignorant plan was just to “stick the MG12 in and hope for the best”, and the plan seems to have worked out well.
As you can see from the following graphs that compare the Edinburgh MG12 against the Lockwood Major MG15 and Lancaster MG15, the Edinburgh MG12 is the smoothest measuring of all of the Tannoy models I've had in this room, and to my ears it’s certainly the best sounding with the least amount of colouration. That doesn’t mean it’s perfect however. There is a broad -3dB trough between 100Hz and 500Hz which makes it sound just a touch thin and clinical. A quick experiment with parametric EQ to boost this region by a couple of dBs restores enough warmth to the sound without making it undesirably bloated, after which there is honestly nothing else I can fault with this loudspeaker. I was already intending to use Dirac to smooth out the sub-100Hz bass response and integrate my XXLS400 subs below 40Hz, so I’ll probably just extend the range it corrects up to 500Hz and call it good, as I really don’t think I can be bothered going down the rabbit hole of playing about with cabinet damping to see what effect this has on the trough, as taking the driver in and out is a PITA. Besides, it may well be caused by floor bounce, since the trough looks more like a series of peaks and dips rather than a flat shelf, in which case altering the cabinet damping will likely have no impact on this.
As I write this I am currently listening to an intentionally mis-matched pair of Tannoys as my other Edinburgh cabinet undergoes its transformation. I have a Lancaster MG15 on the left channel and an Edinburgh MG12 on the right channel and I'm having a swell time! Played together in stereo it’s amazing the similarities these two loudspeakers share. Switch to mono and pan the balance left and right however and the differences become apparent: the Lancaster is superbly musical and engaging to listen to but is ultimately coloured through the bass and mids (i.e. you can hear the cabinet contributing to the sound); whereas the Edinburgh MG12 sounds more grown up and sophisticated, cleaner and more accurate, more solid and grander in scale. Both are excellent in their own way and I will definitely be hanging onto my Lancs as an investment as they are 100% mint (even still have their original boxes) and would be fab if not a touch indulgent in a second system. However, I dare say the Edinburgh MG12 will become my endgame reference speakers, at least as far as Tannoys are concerned.
Here’s a before and after pic of the Edinburgh with 3149 driver (left) and MG12 driver (right). The MG12 sadly doesn’t quite match the 3149’s cosmetic beauty, but that’s a small price to pay for a such a significant sonic improvement! Once I cover up the old bolt holes and missing areas of cork with a 3/4-inch wide “ring” facing of some sort around the driver it should hopefully look (almost) as pretty as before. Any ideas on what I could possibly make this ring out of would be greatly received??!!
I original retired the Edinburghs due to being unsatisfied with their bass output. Over time the surround of the 3149 driver stiffens and consequently raises the Fs significantly, necessitating either a re-cone or a long and arduous process of removing the incumbent doping compound and applying new doping compound. I chose a 3rd and perhaps more radical option; to buy a pair of XXLS400 subwoofers to fill in the missing lows! Once balanced with Dirac, this turned out to be one of the smartest moves I have made. I was now experiencing bass with a smoothness, speed and extension I hadn’t had with any of my previous loudspeakers including the DSP’d Lockwoods. However, the more I listened to the Edinburghs, the more I noticed other colourations, particularly in the mids around the crossover frequency. No problem I thought, I can fix this by applying Dirac to the mids and highs as well as the bass. To a large extent I was right; with full spectrum DSP applied the Edinburghs became much more neutral and transparent in the mids and highs, and the soundstage opened up superbly. However at higher SPLs, there was still an audible harshness that made extended listening quite fatiguing, and no matter how hard I tried I just couldn’t learn to love the sound.
I’m no expert, but as far as factory-built cabinets go, the Edinburgh enclosure seems very well made, and so with the right driver and crossover, I figured it must have the potential to be a stellar loudspeaker. Which got me thinking, what if I replaced the stock 3149 driver with vintage DC driver and crossover? After consulting a couple of Tannoy experts I was advised that the Monitor Gold 15 or HPD 385 would be ideal for the 200L distributed-ported Edinburgh enclosure. However, as a woodworking novice, I was less than enthusiastic about irreversibly enlarging the cutout in the beautiful cork baffle to accommodate a 15-inch driver, so I turned my attention to 12-inch units. After a very disappointing experience with a pair of recently serviced and re-foamed HPD 315s which turned out to be an extremely poor left/right sonic match, I elected to use a pair of Monitor Gold 12s which I'd stored away for a rainy day. Having never measured these, it came as a wonderful surprise to find them matched to ±1dB across most of the range. They are also the flattest of all the Tannoy drivers I have measured above 1kHz. Things looked very promising!
I was a fool to think that it would be a simple process of unbolting the 3149 driver and bolting in the MG12, in fact it couldn’t have been further from the truth! This is what I learned during the process: (1) The bolt holes of the two units don’t line up, so new holes need to be drilled for the MG12. (2) The rear basket of the MG12 is larger in diameter than the 3149, so the baffle cutout needs to be enlarged. (3) MGs are clearly not designed to be front-mounted, as the bolt-holes literally need to be drilled 1mm away from the edge of the cutout, which means if you make the cutout fractionally too big or you slip the drill then it’s game over. (4) The drill holes are so close to the edge of the cutout that conventional tee-nuts are extremely difficult to use to provide a thread for the bolt, so I instead inserted the bolts from the rear and screwed on conventional nuts from the front after the driver had been mounted on the bolts, - not as easy as it sounds!
Two weeks of hard graft and I now have one Edinburgh cabinet fitted with an MG12 driver and its associated LSU crossover. From early listening tests and measurements, I am chomping at the bit to get the other one done! I am very impressed with the sound; it’s transparent, clear, detailed but also punchy and has excellent depth and sense of scale. I’m actually surprised by the quantity of bass; it sits between my sealed Lancaster MG15 (which are too lean IMO) and the Lockwood Major MG15 (which were overbearing IMO) but is better controlled with more speed and less overhang. I don’t understand much about T/S parameters, my ignorant plan was just to “stick the MG12 in and hope for the best”, and the plan seems to have worked out well.
As you can see from the following graphs that compare the Edinburgh MG12 against the Lockwood Major MG15 and Lancaster MG15, the Edinburgh MG12 is the smoothest measuring of all of the Tannoy models I've had in this room, and to my ears it’s certainly the best sounding with the least amount of colouration. That doesn’t mean it’s perfect however. There is a broad -3dB trough between 100Hz and 500Hz which makes it sound just a touch thin and clinical. A quick experiment with parametric EQ to boost this region by a couple of dBs restores enough warmth to the sound without making it undesirably bloated, after which there is honestly nothing else I can fault with this loudspeaker. I was already intending to use Dirac to smooth out the sub-100Hz bass response and integrate my XXLS400 subs below 40Hz, so I’ll probably just extend the range it corrects up to 500Hz and call it good, as I really don’t think I can be bothered going down the rabbit hole of playing about with cabinet damping to see what effect this has on the trough, as taking the driver in and out is a PITA. Besides, it may well be caused by floor bounce, since the trough looks more like a series of peaks and dips rather than a flat shelf, in which case altering the cabinet damping will likely have no impact on this.
As I write this I am currently listening to an intentionally mis-matched pair of Tannoys as my other Edinburgh cabinet undergoes its transformation. I have a Lancaster MG15 on the left channel and an Edinburgh MG12 on the right channel and I'm having a swell time! Played together in stereo it’s amazing the similarities these two loudspeakers share. Switch to mono and pan the balance left and right however and the differences become apparent: the Lancaster is superbly musical and engaging to listen to but is ultimately coloured through the bass and mids (i.e. you can hear the cabinet contributing to the sound); whereas the Edinburgh MG12 sounds more grown up and sophisticated, cleaner and more accurate, more solid and grander in scale. Both are excellent in their own way and I will definitely be hanging onto my Lancs as an investment as they are 100% mint (even still have their original boxes) and would be fab if not a touch indulgent in a second system. However, I dare say the Edinburgh MG12 will become my endgame reference speakers, at least as far as Tannoys are concerned.
Here’s a before and after pic of the Edinburgh with 3149 driver (left) and MG12 driver (right). The MG12 sadly doesn’t quite match the 3149’s cosmetic beauty, but that’s a small price to pay for a such a significant sonic improvement! Once I cover up the old bolt holes and missing areas of cork with a 3/4-inch wide “ring” facing of some sort around the driver it should hopefully look (almost) as pretty as before. Any ideas on what I could possibly make this ring out of would be greatly received??!!