Magnaplanar SMGa - No Treble

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RonnieThomas

Member
Joined 2012
Hi All
I had these Maggies stored for the last 15 years. Just tried them (they were the best speakers I'd ever had) and there seems to be no treble. The sound is sort of 'boxed up'. Was gonna put them on ebay but maybe they are destined for the trash....
Any advice please?
Thanks
Ron
 
A

andyr

Member
Joined 2003
RonnieThomas said:
Thanks John

Is that something I can do myself please??

Ronnie
Click to expand...

You haven't bothered to tell us where in the world you are, so it's a bit hard to give you advice. :)

If you are in the States - send them back to the factory, who will be able to re-lay any corroded drivers.

If you are elsewhere (so shipping is a problem), search the Planar Asylum archives for "delamination repair". Yes, it's something you can do yourself - but you need to get the wire kit sent from the factory. It's not difficult - simply tedious (I re-layed one of my mid drivers).

Regards,

Andy
 
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RonnieThomas

Member
Joined 2012
Maggie SMGa's No Treble

Thanks

I did notice the there is some 'corrosion' around the fuse holders. I took one of the fuses out and it made no difference at all... the speaker just kept working as before (not very well!!)

Is that an indication of a problem?

I'll clean them and try again

Ron
 
G

gootee

Member
Joined 2006
fullnet.com/~tomg/index.html
Use a multimeter set to read Ohms (Ω) and check:

1. With one meter lead on each end of a fuse that has been removed, it should read LOW, probably several tenths of an Ohm, or close to what it reads when the meter leads are touching each other.

2. With a fuse removed, measuring between the "+" speaker input and one of the fuse connections should give a very low reading, less than one Ohm (mostly just the resistance of the coil in the crossover). Measuring between the "+" input and the OTHER end of the fuse holder should then give about 3.2 Ohms (15 Ohm resistor [plus coil resistance] in parallel with 4 Ohm tweeter), if I'm looking at the crossover schematic correctly.

If the measurements from #2 are in the ballpark, your tweeter should be intact, electrically.

One thing I would probably replace first is the 50 uF electrolytic capacitor in the crossover. If it is an electrolytic type, and is original, then it's too old and has got to be replaced. You could use another similar electrolytic, or use a polypropylene. Just make sure the voltage rating is the same or higher.

If you don't have a multimeter or ohmmeter, you could jumper across the fuse holders with wire, temporarily at least, and try playing them at moderate volume to see if there is a difference. But chances seem pretty low that both fuses are blown.

For much more information, I suggest going to

The Planar Speaker Asylum

The crossover schematic is at

MUG Tweaks

Specifically, it's at

http://www.integracoustics.com/MUG/MUG/tweaks/smg xo.gif

I do recommend also at least removing the "socks" that cover the speakers, so you can inspect the drivers and crossover components and connections, etc. There's plenty of info on all of that at the first link I gave.

Tom
 
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A

andyr

Member
Joined 2003
Freecrowder said:
Saw this old thread and was wondering about the outcome with the treble? I just purchased a set of SMG's and they have no treble also. Would like more info on troubleshooting. will look at links provided, my first set of Maggies. Very, very disappointed righjt now.
Click to expand...

You do know about the Planar Asylum, don't you?

The Planar Speaker Asylum

You should get lots of help there.

Good luck,

Andy
 
j beede

j beede

Member
Joined 2007
Magneplanars represent great value, new or used. The down side is that voice coil failure or delamination is usually just a matter of time. I recently replaced the tweeters in an old pair of MG-IIA. I used 30ga copper magnet wire instead of the factory aluminum wire and I was pleased with very slightly shelved down highs that resulted. The tweeters were easy to replace. After looking at the woofers--I decided not to try replacing them and repaired the broken voice coils instead. The worst part of the job is removing the staples that hold the "socks" in place. The hardest part was putting the old fabric back on. I did not have time to order fabric from Magnepan. I would not attempt to reuse the old fabric again. Good luck.
 
j beede

j beede

Member
Joined 2007
Freecrowder said:
Saw this old thread and was wondering about the outcome with the treble? I just purchased a set of SMG's and they have no treble also. Would like more info on troubleshooting. will look at links provided, my first set of Maggies. Very, very disappointed righjt now.
Click to expand...

Sorry to hear that. I gather you bought them before hearing them? The tweeters are very suitable for DIY, the woofers less so. You likely have multiple breaks in tweeter continuity due to corrosion. You will need to strip off the old tweeter wire with acetone and lay down new wires. You can buy wire and adhesive from Magnepan--$50 per tweeter as I recall. I used 30ga copper magnet wire ($4 for 200') and spray adhesive ($10). I was very pleased with the results. A set of "socks" from Magnepan is $90 as I recall. New cloth is virtually mandatory. FYI: I was not impressed with the aluminum soldering kit I bought locally.

Unless you are a serious DIY hobbiest you probably would be happier finding a cleaner/newer pair of used MMG for around $300.
 
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