Mission for Denon SC-M5K and SC-M50 - difference?

[fatmarley]

A couple of pics of the tweeter:

[fatmarley]

Not sure anyone cares, but I'll keep posting for my own records.

I put the tweeter back in and it's working, but it's a lot quieter than the other side. At first I wondered if it was the lack of ferro fluid? but it sounded fine when running an impedance sweep. My guess is the electrolytic capacitor is out of spec. I've got a pair of 4.7uf Anar polypropylene caps on order...

[Macca]

I had the Mission 731LE for a while, they were pretty good IIRC very refined for a budget speaker. Worth fixing if you can.

I'd have thought lack of ferrofluid would make the tweeter brighter not quieter? Maybe the magnet is knackered? But yes can't hurt to try replacing the capacitor, easy fix if that's the problem.

[fatmarley]

I had the Mission 731LE for a while, they were pretty good IIRC very refined for a budget speaker. Worth fixing if you can.

I'd have thought lack of ferrofluid would make the tweeter brighter not quieter? Maybe the magnet is knackered? But yes can't hurt to try replacing the capacitor, easy fix if that's the problem.

I read somewhere that the 731i was better than the 731LE that replaced it, but who knows. Even though the tweeter is not 100%, I much prefer them to the little Denons. Lower mids are much more open and realistic, and they don't sound bright in the upper mids (obviously one tweeter is down in level though). They are bigger speakers, so that could have something to do with it.

You're probably right about the lack of ferrofluid being brighter. My thoughts were from reading up on ferrofluid - One of the factors is the magnetization of the fluid, and I wondered if when the magnet gap is full of it, the magnetic forces would be stronger? My bet is on the capacitor though. The speakers are a bit worse for wear, so I wouldn't be surprised if they've had a good hammering.

I know Alnico magnets can lose their strength, but I've never heard of ferrite magnets doing it.

I'll report back after replacing the capacitor...

[Macca]

From memory there was the 731, 731LE and 731 Pro

Typical Mission, more models than a Littlewoods catalogue.

[fatmarley]

From memory there was the 731, 731LE and 731 Pro

Typical Mission, more models than a Littlewoods catalogue.

Yes, makes it confusing.

I bought my ex-girlfriend some Mission 731s years ago as part of a Richer Sounds bundle, but I can't remember what model they were. All I remember was how good they sounded. Just a very musical, enjoyable speaker, with tighter bass than my Kef Coda 8.

[fatmarley]

Well, there were three separate problems. The Ferrofluid drying out, the 4.7uf electrolytic cap measured 9uf, and there was a break in the 1R series tweeter resistor.