Beovox S120 -Mid-Range repair

[Martin Gordon]

Hi, I recently acquired a pair of Beovox S120 speakers for a nice sum of £30. They had the usual issue of foam rot on the woofers, which I have replaced, and I’ve also replaced the capacitors thanks to a kit from Danish Sound Parts.

However the next problem to resolve is the mid-range driver. On one of the speakers the mid-range driver is distorting/buzzing annoyingly at certain frequencies.

I’m fairly inexperienced when it comes to speaker repair and wondered if anyone had any tips on how to fix this issue. I came across this video on  S80 repair, which I believe uses the same mid-range driver.  Would this be the best way to go about fixing this issue?

[AdamS]

If you’re lucky, it may just be the foam behind the driver. There’s a sheet of foam that is pressed by the plastic cover behind the midrange and tweeter to provide pressure form the rear to hold it in place. This foam can age and deteriorate, so the midrange isn’t being held in firmly, and can rattle. Change the foam or add a bit more in, and this may well fix it.

If you’re unlucky, it may be the same problem i had with both my MS150 midranges, where some idiot re-capped the crossovers in the past and put the wrong capacitor values in the midrange circuit, allowing too much low frequency to get to the driver, and eventually causing the voice coils to overheat and fall off the formers. When you re-capped, were all the new capacitors the same value as the ones you took out?

[Martin Gordon]

Hi Adam, thanks for the reply.

I don’t suspect it’s the capacitors in the crossovers. The problem was present before changing them over and the values were all correct in the replacement kit sent by Danish Sound Parts. My hope was that changing the capacitors would resolve the issue, but this has not been the case unfortunately.

I’ve taken a look at the foam previously and it looked good at first glance. I’ll try adding extra padding to see if this fixes the issue and report back.

[Martin Gordon]

I tried a halfway house solution this afternoon of adding more padding and it seems to have improved slightly. Fingers crossed that this is the root cause as it would be a big jump in my DIY skills to repair the midrange driver.

AdamS, do you remember what type of foam/padding you used?

[AdamS]

I didn’t actually need to do mine as the foam was fine – as above, it was the crossover damaging them!

As to the capacitors, I have absolutely no doubt that the capacitors in the Danish Sound Parts kit will be correct – my question was whether they were right before this? Like I said, someone had been at mine before I owned them, and one of the capacitors in each crossover was wrong – I only found this out when I fitted the new capacitor kit.

[Martin Gordon]

OK, in my speaker the capacitors were untouched and all the values were as they should be. I’ve had another tinker this afternoon and I think the extra padding has worked and re-adjustment of the foam has worked, so time to start enjoying these great speakers!

[AdamS]

Excellent news – enjoy!

[Author]

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