Is that serious? (pic inside)

[admin_exported]

One of my MA Studio 10s recently suffered from a quiet tweeter. I decided to open up the lil' beast. I was shocked and amused to find a vinyl brush bound (magnetically) to the driver unit. I was also less amused to see a lot of corrosion on the end of the internal wiring.

Is this something I should worry about and get put right by sending the pair out for a service? I'm concerned that maybe they don't sound as pure and great as they could, despite their age. These were made around 1990. Got them second hand about less 2 years ago.

 

[Anonymous]

You could try re-wiring them yourself using some half-decent speaker cable and high quality / purity silver solder (go to Maplin if all else fails). Just rewire between the insides of the binding posts and the crossover and between the crossover and the speaker terminals. Follow the colour coding or whatever of the old wires to avoid getting things out of phase. If you're brave and the speakers will bi-wire, you could bypass the crossover all together?

 

[Frank Harvey]

Bypassing the crossover wouldn't be recommended unless you know exactly how it works: crossover points etc. The HF unit will always pass through filtering, otherwise a full range signal will fry it. Some manufacturers let their bass and/or mid drivers roll off naturally, which in this case you could wire direct. But if the mid or bass drivers have been tailored to crossover at a certain point (before it's natural roll off point) by the crossover, you would HAVE to pass through the crossover.

 

[Anonymous]

I just want to reinforce what Dave from FrankHarveyHifi has just said - do not try bypassing the crossover!!! even if the signals dont fry the drive units you will experience different output levels which will throw the whole sonic output out of alignment.
Get yourself some decent cable - you can buy solid silver wire via ebay for around £8/m : http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=350157734078&ssPageName=STRK:MEWNX:IT
this will go a long way to improving the sound from your speakers and will be very resilient to corrosion.

 

[Anonymous]

I stand corrected. Which begs the question - why bi-wire at all?

 

[Messiah]

Also makes you wonder why so much is spent on speaker wire when you see what is used inside. The stuff in the picture looks like THIS

 

[Anonymous]

Which in turn makes you wonder whether, once they're out of warranty of course, it's worthwhile opening up your speakers and re-wiring them as a matter of course, provided you can handle a soldering iron without burning the house down......

 

[Anonymous]

the length of the wire within speakers means youre unlikely to get much if any benefit at all

 

[proffski]

Quite right, ignoring the crossover unless you are considering Bi-Amping would be an expensive mistake at least as far as the tweeter is concerned. Secondly some crossovers also incorporate equalisation in their design. Bi-Wiring is not the same as Bi-Amping! Bi-Amping would obviously require another amplifier and an external electronic active crossover as opposed to an internal passive one.

 

[Frank Harvey]

Darren Heal:I stand corrected. Which begs the question - why bi-wire at all?On some speakers, it is a case that the lower terminals are connected directly to the bass driver to utilise it's natural higher frequency roll off, then the crossover is used to marry up the HF unit to match in. I can't remember who used to do this now, but I think it was Royd.

Shame Royd aren't still around - they could've done a special edition speaker in pink called The Pink Royd.....

......I'll get me coat.

 

[Anonymous]

momo72:
... I was shocked and amused to find a vinyl brush bound (magnetically) to the driver unit. I was also less amused to see a lot of corrosion on the end of the internal wiring.

It could easily be that the previous owner had discovered the corrosion and tried to remove it with the exact brush you found?

As recommended by others I would also suggest that you just try to redo the wiring - but I have to say that with a pair of loudspeakers this old you may get a lot better sound just buying new ones (I know - much more expensive solution as well) since loudspeaker technologies has developed over the years.

 

[fatboyslimfast]

proffski:Bi-Wiring is not the same as Bi-Amping! Bi-Amping would obviously require another amplifier and an external electronic active crossover as opposed to an internal passive one.

Not quite - Bi-amping works on the same prinicpals as Bi-Wiring (i.e. the speaker's internal passive crossover stays in place, but one amp drives the LF side of the crossover, and one the HF). What you have described is active crossover and amplification, and is a whole different world, both in sound quality and cost!

 

[Anonymous]

getprogs:It could easily be that the previous owner had discovered the corrosion and tried to remove it with the exact brush you found?

I think it's more likely the previous owner's kid(s) did a trick on him and pushed the brush through the rear port.

As recommended by others I would also suggest that you just try to redo the wiring - but I have to say that with a pair of loudspeakers this old you may get a lot better sound just buying new ones (I know - much more expensive solution as well) since loudspeaker technologies has developed over the years.

I'm not considering buying new ones yet (although I started looking at websites last night... bad sign), but a service might have to happen sooner rather than later.

 

[Overdose]

To get back on topic. No, it's not serious at all and is an easy and cheap fix.

If you're confident with a soldering iron, then just replace the wires yourself with some OFC wires of the same dimensions or slightly thicker. Make sure to maintain original polarity and routing.

You could also send them in to an electronic repair shop and have them do it. That should be an hours work tops.

Before sending them away for repair though, just give the drivers a once over for obvious damage, such as deteriorated suspension. No point repairing a BER pair of speakers.

 

[Anonymous]

I'm thinking of giving this re-wiring job to 1st Stop AV Ltd in London as I work next door. Are they "recommendable"?