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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment.

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Old 19th Sep 2019, 12:17 pm   #1
Colin Boggis
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Default Speaker Repair

I don't know if this method has been used before, but I just repaired a speaker from a DAC90A with total success. The voice coil was off centre & rubbing as the fabric centring ring had come unstuck. Initially I tried to release the cone from the frame using various solvents but all I managed to do was pull off the thick cardboard trim. I then decided to take a chance and go for broke - I disconnected the 2 wires on the rear of the cone from the voice coil and then, using a sharp craft knife, cut round the perimeter of the cone. Once this was done the cone came out easily. After cleaning the frame I ran 5mm of silicone sealant right round the edge of the frame just adjacent to the fixing rim. I put a little JB weld (slow cure epoxy) round the edge of the fabric ring and then refitted the cone with 3 fine card spacers inserted between the pole piece and voice coil former, spaced at 120 degrees. I gently pressed the edges of the cone into the silicone until it sat evenly all the way round. It was the n left overnight. The next morning I removed the spacers and was pleased to fid the cone moved in & out without rubbing. I resoldered the voice coil wires and tested the speaker. Much to my surprise It works fine. So one refurbished speaker at very little cost.
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Last edited by Colin Boggis; 19th Sep 2019 at 12:19 pm. Reason: Add pictures
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Old 19th Sep 2019, 1:55 pm   #2
unitaudio
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Default Re: Speaker Repair

Well worth the effort, old speakers aren't too thick on the ground nowadays.

Regards,
Paul
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Old 20th Sep 2019, 8:14 pm   #3
crackle
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Default Re: Speaker Repair

I have had the same fault with one of these speakers. it must be common on the DAC.
I found there was no need to remove the cone. With 3 shims inserted to centre the voice coil the cone could be pulled up leaving a gap to put glue around the rim of the inner centre ring with a fine paint brush.
Then just push the cone back down so the fabric pushes on the frame and leave overnight.
I didn't want to risk removing the fine layer of rust as it would have gone in the voice coil gap.

Mike
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Old 21st Sep 2019, 4:38 pm   #4
Colin Boggis
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Default Re: Speaker Repair

Reading the repair Crackle carried out, I think I may have gone a step to far by cutting out the cone! Good one Crackle.
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Old 21st Sep 2019, 7:10 pm   #5
crackle
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Default Re: Speaker Repair

Which ever way you do it a speaker was saved, well done.

Mike
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