Newbie here. I just picked up a pair of Tannoy Mercury M1's for free. The owner said the woofer was dead on one and I thought it would make a suitable first DIY audio repair. I connected it and the woofer wasn't dead but was sounding like a tweeter. Opened it and sure enough someone had connected the tweeter wires to the woofer and vice versa (maybe when they were adding polyfil to the cabinets). Checked the tweeter with a 1.5 voltage battery and it was definitely dead. I had an old pair of Gennexa (optimus) Pro X7s in the basement with tweeters that looked almost the same (both speakers are 8 ohm though the Gennexa's are 89 db sensitivity and the Tannoys are 87 db). After fashioning a new mounting plate for the tweeter out of fibre board, I connected the tweeter and was pleasantly surprised that I couldn't hear a discernable difference between the two speakers. What I'm wondering though is whether the original tweeter might be salvagable and how difficult/expensive it would be to fix it? Thanks.
How the tweeter would be fixed if a butterfly could be found, is to remove the plasticbit you still show in the top picture, make sure everything is clean with no debris in the gap — did the voice coil come out with the dome? Then carefully install the butterfly (the plastic bit with a working dome attached), reinstall the face plate and away you go.
dave
dave
I guess somebody mistakenly fitting the woofer signal wires to the tweeter would cause the mess in your view of the tweeter voice coil gap and magnet.
You can see the remnants of one of the tweeter tinsel wires and bits of the voice coil still stuck in the magnet gap I think.
It does look like it could be a replaceable item by fitting the new whole plastic assembly, I do not know if Tannoy was using its own drive units at that time or if it is a Vifa or Peerless tweeter they used.
The fact that you managed to replace it, and get it up and running is good. If you can live with the looks then maybe a bit more resistance in the tweeter feed could get you close enough to match the volume level of the other speaker. Can you see the Xover and the resistor values currently fitted?
You can see the remnants of one of the tweeter tinsel wires and bits of the voice coil still stuck in the magnet gap I think.
It does look like it could be a replaceable item by fitting the new whole plastic assembly, I do not know if Tannoy was using its own drive units at that time or if it is a Vifa or Peerless tweeter they used.
The fact that you managed to replace it, and get it up and running is good. If you can live with the looks then maybe a bit more resistance in the tweeter feed could get you close enough to match the volume level of the other speaker. Can you see the Xover and the resistor values currently fitted?
Thanks for the instructions Dave! Much appreciated. I've been looking for a butterfly online without success but will continue...
Actually, the volume levels seem pretty synced, in my ears anyway, and the speakers do sound very crisp and clear with good imaging etc (better anyway than the Boston acoustics hs 225s they're replacing). And the looks don't bother me as the speakers came with fully intact grills. Now if you'll excuse a possibly dumb question, how would I go about seeing the Xover and resistor values? Thanks.
Not a dumb question if you haven't done this before.
The Crossover could live on the back of the rear connection terminal, use of hotmelt glue or some such allow the manufacturers to mount a few small components there. Alternatively it could be on a larger piece of hardboard/ wood or a printed circuit board. you should possibly see it from the tweeter cut-out when you removed the tweeter, or it could be hidden under some foam or sound absorber fill.
The other way of getting to it would be to gently remove the six woofer screws and gently remove the plastic cover and bass driver. note that the plastic will be brittle with age and the woofer will have probably stuck to the cabinet via its thin mounting gasket. So please exercise care if you want to do this
Alternatively, the much easier option is to do a google image search for tannoy mercury M1 crossover schematic which may have already be posted on one of the pages here as it was a popular model at the time.
Also as you seem relatively content with where you are now after your fix, you could simply live with what you have now.
The Crossover could live on the back of the rear connection terminal, use of hotmelt glue or some such allow the manufacturers to mount a few small components there. Alternatively it could be on a larger piece of hardboard/ wood or a printed circuit board. you should possibly see it from the tweeter cut-out when you removed the tweeter, or it could be hidden under some foam or sound absorber fill.
The other way of getting to it would be to gently remove the six woofer screws and gently remove the plastic cover and bass driver. note that the plastic will be brittle with age and the woofer will have probably stuck to the cabinet via its thin mounting gasket. So please exercise care if you want to do this
Alternatively, the much easier option is to do a google image search for tannoy mercury M1 crossover schematic which may have already be posted on one of the pages here as it was a popular model at the time.
Also as you seem relatively content with where you are now after your fix, you could simply live with what you have now.