Speaker Distortion on a Pye D18T - UK Vintage Radio Repair and Restoration Discussion Forum

DoctorWho · 1st Oct 2006, 9:05 pm

I had serious speaker distortion on a Pye D18T which was very bad and made everyone sound as though they were blowing raspberries.

I decided that I didn't have anything to lose and so I took the speaker out of the cabinet and examined it, I found two nuts on the back of the magnet assembly which, when undone, allowed the magnet to be withdrawn from the cone.

The problem was then obvious, there was surface rust on the magnet which was also on the paper inside the coil of the cone.

First I cleaned up the inside of the coil with emery paper and got it smooth again, then I used emery to clean up the magnet assembly and got rid of all of the rust, it took a few attempts to get rid of all of the rust and also line the magnet back up again by loosening the central screw in the magnet assembly and centralising it and tightening up again.

The end result was well worth the effort though, the magnet assembly was bolted back in to place and the sound quality is now superb, even at full volume.

It sounded daunting, but was actually much easier than it sounds and I'd strongly advise that anyone gives it a go if you get a speaker like this, as it's always better to preserve an original rather than replace it, and the resulting sound quality made it all worthwhile, the set now sounds magnificent.

I hope this may be of help to someone else.

Peter.

chipp1968 · 2nd Oct 2006, 8:43 pm

I have done this before with good results , but its not always easy to take the thing apart , so you were lucky

DoctorWho · 2nd Oct 2006, 8:53 pm

Yes indeed, the unboltable magnet assembly made life easier, having to remove the cone would have made it far more complex and fiddley.

Sideband · 2nd Oct 2006, 8:59 pm

I did a similar thing with a Murphy radiogram a few months ago. I don't know how the owner could have listened to the 'wonderful tone'?? Fortunately I didn't have to remove the magnet. What had happened was that the corrugated suspension ring around the voicecoil had detached itself from the metal frame so the cone was only suspended around the edge of the speaker. I had to carefully cut out the dustcap in the centre and use some paper shims to centralise the cone. All I did then was to glue the suspension ring back in place using 'Evo Stik'. When I took the shims out an hour or so later, the speaker was perfect. I was able to refit the dustcap and when tested, the sound was back to normal with no scratching even at high volume.

Rich.

Ghostuser · 13th Oct 2006, 11:11 am

I had an HMV445 where the speaker cone surround had been eaten away by some creature. The remains appeared to have been four segments of very thin leather and I was able to cut some new pieces and super glue them in place. This set has large cone movements due to a strong bass response and the result was excellent.
Nigel

1st Oct 2006, 9:05 pm	#1
DoctorWho Rest in Peace Join Date: Apr 2005 Location: Devon Posts: 850	Speaker Distortion on a Pye D18T I had serious speaker distortion on a Pye D18T which was very bad and made everyone sound as though they were blowing raspberries. I decided that I didn't have anything to lose and so I took the speaker out of the cabinet and examined it, I found two nuts on the back of the magnet assembly which, when undone, allowed the magnet to be withdrawn from the cone. The problem was then obvious, there was surface rust on the magnet which was also on the paper inside the coil of the cone. First I cleaned up the inside of the coil with emery paper and got it smooth again, then I used emery to clean up the magnet assembly and got rid of all of the rust, it took a few attempts to get rid of all of the rust and also line the magnet back up again by loosening the central screw in the magnet assembly and centralising it and tightening up again. The end result was well worth the effort though, the magnet assembly was bolted back in to place and the sound quality is now superb, even at full volume. It sounded daunting, but was actually much easier than it sounds and I'd strongly advise that anyone gives it a go if you get a speaker like this, as it's always better to preserve an original rather than replace it, and the resulting sound quality made it all worthwhile, the set now sounds magnificent. I hope this may be of help to someone else. Peter.

2nd Oct 2006, 8:43 pm	#2
chipp1968 Rest in Peace Join Date: Jul 2006 Location: Somerset, UK. Posts: 2,356	Re: Speaker Distortion on a Pye D18T I have done this before with good results , but its not always easy to take the thing apart , so you were lucky

2nd Oct 2006, 8:53 pm	#3
DoctorWho Rest in Peace Join Date: Apr 2005 Location: Devon Posts: 850	Re: Speaker Distortion on a Pye D18T Yes indeed, the unboltable magnet assembly made life easier, having to remove the cone would have made it far more complex and fiddley.

2nd Oct 2006, 8:59 pm	#4
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,580	Re: Speaker Distortion on a Pye D18T I did a similar thing with a Murphy radiogram a few months ago. I don't know how the owner could have listened to the 'wonderful tone'?? Fortunately I didn't have to remove the magnet. What had happened was that the corrugated suspension ring around the voicecoil had detached itself from the metal frame so the cone was only suspended around the edge of the speaker. I had to carefully cut out the dustcap in the centre and use some paper shims to centralise the cone. All I did then was to glue the suspension ring back in place using 'Evo Stik'. When I took the shims out an hour or so later, the speaker was perfect. I was able to refit the dustcap and when tested, the sound was back to normal with no scratching even at high volume. Rich. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

13th Oct 2006, 11:11 am	#5
Ghostuser Pentode Join Date: Oct 2003 Location: Alton, Hampshire, UK. Posts: 137	Re: Speaker Distortion on a Pye D18T I had an HMV445 where the speaker cone surround had been eaten away by some creature. The remains appeared to have been four segments of very thin leather and I was able to cut some new pieces and super glue them in place. This set has large cone movements due to a strong bass response and the result was excellent. Nigel