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

[vintagesteve]

I own a few pairs of Mission for Denon SC-M5K bookshelf speakers that I use for general tinkering and garage use. They are delightful little speakers for what they are, and especially regarding how cheaply they can be bought. I am also aware of a very similar (almost identical) looking model, the SC-M50. If you look at the latter with the grille removed, it has grooved 'lines' where the drive units and port meet, whereas the SC-M5K is one smooth moulding, no grooves. See photos. Now, I'm sure that little cosmetic detail is not the only difference, and I'd like to know just what the difference is between these two Mission for Denon bookshelf speakers? I presume one came out before the other and the second one was supposed to be an upgrade? If you know any more than I've said here I'd be interested to hear what you have to say. Thanks in advance.

2494224943

[fatmarley]

Old thread, I know.

I just bought a pair of Denon SC-M5K for my PC, and I found a video comparison here that says the UK version (grey front) is better built and sounds better. The tweeter material looks very much like an Audax unit (that's a good thing) and it says made in France on the back, so I'd be very surprised if it wasn't.


https://www.youtube.com/watch?v=5DtiHLhfdBc

[Macca]

little differences but would not be surprised if they added up.

[fatmarley]

They have different tweeters and a different crossover, so you'd expect some difference.

At some point I'll probably measure them and try to reverse engineer the crossover.

[Macca]

I'm assuming the different crossover is to correct for the different tweeter to give the same outcome, in theory.

So you have the Malaysian version or the UK one?

[fatmarley]

I'm assuming the different crossover is to correct for the different tweeter to give the same outcome, in theory.

You'd think so, but apparently the Malaysian version is supposed to be a bit brighter and not quite as nice sounding.


So you have the Malaysian version or the UK one?

The UK version with the grey front and suspected Audax tweeter. I'll high-pass them and use them with a sealed subwoofer (Peerless XLS10) and a TPA3116 2.1 amp I bought off ebay for around £20.

[Macca]

Malaysian is obviously cost cut - just having the drivers flush like on the UK version should improve the response.

Be interested to see what you think of them with the high pass and sub.

[fatmarley]

Malaysian is obviously cost cut - just having the drivers flush like on the UK version should improve the response.

Be interested to see what you think of them with the high pass and sub.

I'll report back, but it probably won't be until after Christmas due to postage delays...

For anyone who's interested, Missions version was the Model 70. It was a bit smaller, so I'd imagine it will have a bit less bass depth. It looks like they use the same tweeter as the UK version.

https://www.avforums.com/attachments/d8227898-c75d-4c8f-a795-0458a39fa836-jpeg.1341468/

[fatmarley]

The speakers arrived early. They are a lot smaller than I expected - cute little things.
The sound isn't bad, but there is a little bit of brightness in the upper midrange. I haven't tested them on my main system, so it could be a problem with electronics.
I also bought some cheap Mission 731i from ebay that are a little bigger, but one of the tweeters isn't working :(
There's no output when measured with my microphone, but on removing the tweeter, and taking an impedance measurement, there is sound, but the impedance peak is almost flat (the other tweeter has the usual peak at resonance)
I will swap the tweeters and see what happens...

I'm wondering if there are two problems. The tweeter out of spec and a fault in the crossover.

[fatmarley]

Here's the impedance of the good tweeter:

https://i.imgur.com/3kvVY2h.jpg

Here's the bad tweeter:

https://i.imgur.com/cfvNJjO.jpg

And here's the faulty tweeter with the ferrofluid removed. I'm waiting on the new ferrofluid before I glue the tweeter back together.

https://i.imgur.com/ZWm56yK.jpg

[fatmarley]

A couple of pics of the tweeter:

https://i.imgur.com/JUl4Kvz.jpg

https://i.imgur.com/CklMnta.jpg

[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.