speaker refoaming?

[Simon T]

Not sure if this is quite the right group, but the woofer speaker in my old Toshiba TV has started making a nasty rattling sound. Took the set to bits to find the foam around the edge of the speaker has perished.

Problem is, with it being such an old set, you can't get replacement speakers, however I am aware that you can get "re-foaming" kits. Though I am struggling to find a kit for such a small speaker (measures 4" across the housing, the speaker cone itself is 2.75").

Not had much luck on Ebay and most places selling these kits (which I am struggling to find the right size for) seem to be based in the US.

Any suggestions?

TIA

[The Natural Philosopher]

I have some sites for that..have to do some wooofers..

be worth a bell

[Dave Plowman (News)]

You may not be able to get an identical unit, but have you tried for one which fits? It's hardly likely to be critical in a TV.

Somewhere like this would be a start:-

Not had much luck on Ebay and most places selling these kits (which I am

[Martin Brown]

If it hasn't gone too far then some tissue paper and PVA adhesive will do a bodge job almost as good as the original at that size.

A better bet is look for a similar size and power rated impedance loudspeaker that will fit in the physical space. If it is inside a tube based set it needs to be a magnetically screened unit intended to be used in a CRT based set. Beware that chassis may be live on old TVs.

RS is not the cheapest place to buy but they do have some:

that or you will have to get used to funny colours in one corner.

[Scott M]

Or put the speaker outside the TV. World must be drowing in unwanted speaker cabinets.

[Alan]

In message , Simon T wrote

Foam draught excluder??

Probably cheaper in your local pound shop.

[grimly4]

There's a guy on ebay sells kits - ask him for your size, and he'll have it, most likely.

bloke...

[NT]

I'd be amazed if you can't find a suitable replacement speaker. You cuold probably use 3mm underlay to re-suspend it. Get the cone alignment right, they are fussy.

NT

[mick]

Would this fit?

this?

[Simon T]

Thing is, when it talks about 4" speaker, is it on about the outside diameter of the case, or the diameter across the top of the speaker cone?

[Andrew Gabriel]

This thread reminds me... A few years ago, my parents' 1970's Sony HiFi stopped working. I opened it, and quickly found the +40V supply was dead, which besides being half the power supply for the output stage, was also the supply for the pre-amp, tuner, and front panel lamps, so it did nothing. I mended the PSU (failure was caused by the glue used to hold some heavy components to the PCB slowly corroding the copper tracks).

They reported that it still sounded very distorted, and it did when turned up loud. Took it home, ran it with a signal generator and dummy load on a scope, and it looked fine. Took it back to them - same problem. Then I thought to switch to another set of speakers, and it was fine.

So I disassembled the speakers which didn't work (bass reflex cabinents designed and built by my dad in the 1960's, although he fitted new drivers and retuned them in the 1970's when they switched from a valve amp to this new Sony one). At that point it was obvious what happened - the PSU failing in the amp had blown both speaker cones right out. The amp is DC coupled with no built-in speaker protection circuit, so the speakers very likely got a full 40VDC across them when one half of the PSU failed. Foam surround ripped in half completely, all the way around.

With new drivers fitted, it's now working fine. I haven't retuned the ducted ports as the drivers look pretty identical to the blown ones, but I might do that one day.

[mick]

It's usually the frame size (and it is here). The cone diameter isn't always given. In this case there are links on those pages to pdf files which have dimensional drawings.

[thirty-six]

Bodge it. Use micropore tape to make at least five suspension points at the cone edge. It wont be as efficient as a proper job, but hey, it gets it working without worrry.

[Dave Plowman (News)]

You need a decent air seal between front and back of the cone.

[thirty-six]

I know how it works, but the bounds of acceptability in sonic performance change according to whether one is attatched to a particular piece of equipment. I'm not and I have used the repair method on my own speakers. Rebuilding half the edge support with bits of tape gets one over half way there. \it's not as designed but still acceptable in many cases.

[Dave Plowman (News)]

Given it's a bass unit any leaks will be even more disastrous to the performance. With higher frequencies you may get away with it. Basic physics.

[thirty-six]

So it's not a sub-woofer. more of a yapper.

Good job my audio perception is not too fussy about exact physics. I've done it, it's mostly good enough if half of the edge is reconstructed. It's not Hi-fi, but very few TVs ever came close, although I did have a Ferguson which could drive some external speakers quite well. Great design and componentry let down by a poor PCB construction, believed to be Thomson and built in France.