Magnepan MGII Repair/Restore, Glue, Glue and more Glue

[FireGuruMN]

I bought a pair of MGII last fall on CL for $200.00 with known issues. They sat around during the winter because there was no way quality control would allow stinky glue in the house. I once finished off an entire office with Victorian woodwork, built in shelves, wood ceiling and did all the staining and sealing indoors over the winter. There is not enough ventilation in the world to make me do anything like that again.

One speaker had the sock and wood removed so I knew there was a LOT of delamination that needed fixing. The previous owner even had the repair kit from Magnepan to make the repairs. He just did not have the patience I am guessing.

So now that the grass is green in Minnesota it is time to have at it.
Here is what MGII's look like if it matters:

I said LOTS of delamination right:

At least the ends are firmly attached. If you don't know the theory behind these speakers here is the executive summary:

• The face of the speaker has long strips of magnets.
• Behind that is a mylar sheet.
• Wires are glued to the mylar sheet.
• Current flows through the wires from your amplifier and the mylar gets sucked in and out from the magnets.
• That makes music.
• There are thin wires for high frequencies, thick wires for low frequencies. Weights on the mylar to make the frequencies even lower.

Because it is an imperfect world the wires come unglued from the mylar and start making nasty vibrations that are not music.

Firstly, I tested the speakers to ensure that all the wires were conducting all the way through. Basically hook them up and make sure sound is coming from everywhere on the mylar. If areas are dead then you have to find the break and fix it. It's mostly a long continuous run so it will be obvious if something is broken. Mine were all good so if you have broken ones this post is no help.

There are many many opinions about how to reattach the wires. Google away. I will wait. . .
The repair kit that comes from Magnepan actually contains an instruction sheet on how to make the repairs. It is about as useful as the sex education class I had in 8th grade. That is to say, not much use in the real world.
So my plan:

• Use acetone solvent to remove the old glue.
• Use DAP contact adhesive to glue them back down applying it with tiny disposable makeup brushes.
• Apply the Magnepan glue at the end as recommended in the instructions because the only other thing would be to dump it down the drain.

If you are in any way OCD (obsessive compulsive disorder) and you are on medication, I recommend getting off the medication before starting this project. Consult your doctor. It is tedious work.

I started on the thin tweeter wires. I think I have more wires separated than most people. I don't know the history of these but it was not being stored in a museum for sure.
This is a really bad area with a tear in the mylar also. The wires are about 1/4 inch apart.

That might be a burn more than a tear because the wires were black. But they are not broken so I moved on. Setup a light so it casts shadows of the separated wires:

For the tweeter wires use as little glue as possible to hold them down. If the mylar gets heavy it will not make high frequencies as well. Basically I held the wire in place and brushed over it with some glue. Many of my wires were too long for whatever reason. It is important that the wires be lined up with the magnets but they have to be glued down. I ended up making waves in the wires to keep them over the magnets and glued down. Not the best choice but the other option is to pull the wire off all the way to the end and that was not going to happen in my world.
Not pretty:


Continued. . .

 

[FireGuruMN]

So I got past the tweeter wires. I hooked it up to an amp to ensure I still had signal and then moved on the the thicker wires where there was much much more delamination.
It appeared to me that someone had already removed the old adhesive or it was entirely gone or it never existed. So I was spared the cleaning part of the project. The wires were totally clean as far as I could determine.
Again, not pretty. The glue was globbing. The brushes were dissolving in the glue. The wires were too long and would not stick down even with lots of waves. It was like the entire bottom of the mylar had shrunk. Maybe it overheated and did shrink. But I worked out a rhythm. Apply glue to one length (about a foot). Let that setup while pressing down the previous wire. And keep that process going. I made it through about a square foot doing that.

Run the end of the brush along the wire as it sets up. Your fingers will get covered in glue if you try to press down with your fingers.

This is NOT how it should look if you did a good job:

The 4 black circles on the right in the green goo are the weights on the mylar. Like it matters.
These are the brushes I used. Great for cleaning tube sockets and such but the bristles were falling off with the contact cement.

At this point I figured the entire project was a total loss and I was just going to get it done and get on with my life. Ain't no body got time for this. Bring out the big glue can and the big brush!

I put on a thin even coat and let it set up a bit. Then I just worked rubbed over each wire with the end of a brush constantly as the glue was setting up. Eventually they started sticking. Maybe 10 minutes working time. That process actually worked very well. The Magnepan instructions talk about using a spray adhesive so maybe the wide area process is what was intended. Either way that us what I recommend if you have a lot of loose bass wires.
Let the contact cement setup for how ever long the instructions say. I can't read instructions because I am an engineer so I waited until it felt dry and put on the glue that Magnepan included in the repair kit:

I thinned it out more than is shown here. The glue is called "3M 30NF" if it matters. It goes on white and dries clear. I have the feeling that most of the glues are mostly water or alcohol and not much residue is left behind after everything evaporates. That is good because the weight of the moving mylar diaphragm should not change in a perfect world.

Continued. . .

 

[FireGuruMN]

While that was drying I grabbed the other speaker. I removed the wood. Just screws holding the wood on. Sides first, top has 2 screws and a couple of nails, bottom just falls off. Fuse and speaker terminals are held on with 2 screws. There are 2 trim strips on the face of the speaker. They come off fairly easily but they are VERY FRAGILE. Be gentle.

It occurs to me that I should have put all this at the beginning of this thread but since one of mine was already stripped it ended up here. So sad. Then you have to take the sock off. There are more staples holding the sock on than could possibly be necessary:

AND there is another layer under this layer. Turns out this is a good quantity of staples. More on that later.

Try to remember how the staples were applied and how the fabric is folded. It is important if you want to put the sock back on correctly with out waves, wrinkles, tears and other nasties.
Copper staples:

A sign of quality? Better acoustic properties? I replaced them with stainless steel because that is what I had. I'm thinking both material will not rust and rust would be bad. One of these speakers had sees some water on the bottom.
Then I got some good news:
The wires on the second speaker looked almost perfect. Kind of like a good-twin bad-twin story. Whatever. I will take it as a gift. I put some of the Magnepan glue on just to make sure the wires stayed where they were and brought them inside to dry. It was a bit too cool outside for glue to setup properly.
Wood restoration:
Put some sort of oil on the wood and it looks prettier. Done.

I like cherry even though this is oak. Mohagony is another good choice. Whatever makes you happy will make the wood happy.
Reoiling wood is pretty much the most satisifying/gratifying thing you can do in your garage:

Here is another picture of that tear. I made sure to keep it from gluing to the magnets. The brown thing is a magnet if you care.

I replaced the 10uf capacitor. The old one was probably fine but replacing speaker caps is what I do. I had a 10uf but it would not fit. Well it would fit but it left a bulge. So I had two 4.7uf's and a couple of 0.1uf bypass caps that got close enough to 10 to keep my electrons happy.

There is a log of glue over the terminals so I chose to attach to the leads of the old capacitor instead of trying to get under the glue. Those tiny tiny tweeter wires are not fun to repair.
ALWAYS check every fuse in every piece of equipment you are restoring. The correct fuse is a 3 amp. Mine both had 20 amp fuses installed. Face Palm.


Continued . . .

 

[FireGuruMN]

So eventually all my oil dried and glue setup and capacitors capped and fuses fused. I hooked the speakers up without the socks and wood on just to see what sort of an abomination I had created through my hack job repair work.
A word of warning: These speakers need a lot of power and they can drop to VERY low resistance during normal operation. I was using a Denon 4806 and had the volume up to 0db before they even started sounding good.

Oops, Did I say they sounded good. OMG, yes I did say that. And OMG they really really do sound good. Imagine how they would sound if they were properly repaired! Where the heck is all that bass coming from? And treble everywhere in the room! I gotta get these done and hooked up to a proper system.

Time to put everything back together, Caution: more hack work coming:
I am thinking that there are distortions in space here in Minnesota. No matter how much I stretched, pulled, twisted and swore at the socks, I could not get them stretched so I could staple them the way they came off. So I saw that I had about 1/2 inch at the bottom that was covered by the bottom board. So here is what happened:

You have to put in LOTS and LOTS of staples because this fabric shreds incredibly easily. What is it, 40 years old? Some year I will replace it. Maybe. Not this year.

The trim strips are another beast. There are nailing surfaces behind the grill cloth. They are not symetric up and down the speaker. So find the tiny little staples and make sure they line up with the nailing surfaces before you start nailing. Also, STRAIGHTEN the legs of the existing staples before putting the strips back in place. I found that if you use a very flat hammer and hammer directly above the staples you can mostly reuse the existing staples. But the wood putty gets trashed and other issues. Maybe just try and put in new staples if you have the right tool. Cut a gage block to get them lined up right:

One of mine vaporized when I hit it:

I think they were stored on a wet floor when they were off the speaker? That will be fun to match the stain. I have not dealt with it yet.
Oh, there is a UP and DOWN to the side boards. The UP is where the nail is. The nail is sharp and rusty. Be careful. Orient it correctly so it lines up with the wood blocks in the speaker that you cannot see anymore because the sock is on. If you were smart and numbered them you might be able to line up with the old screw holes. If not, press hard while drilling a new hole.
This was interesting (compared to what you ask):
Magnepan makes stubby banana jacks (bottom) to go with their thin speakers:

A set was in my repair kit special ordered by the previous owner I think. The normal ones work fine for me but you might need the stubby ones when you are back on the OCD meds.

Continued. . .

 

[FireGuruMN]

So I think these speakers were hung from a wall in their previous life. There were hooks near the tops of the speakers. Don't hang these speakers on the wall. If you are going to hang them on the wall, sell them instead to someone who will appreciate them. IMHO.
I googled and googled trying to find what the original stands might look like. Nothing. Nada. Zippo. So I tried Bing. HAHAHA just kidding. There were screw holes in the bottom of the base board. All the way across. That might be significant. Who cares. I'm doing my own thing.
Prototype:

Just clamped on. Gotta have them tipping back a bit so they don't fall forward because the front of the stand is shorter than the back. 3 degrees maybe?
Spoiler alert. This is what I built:

1x3 red oak. The original wood on the speakers was oak. Oak is nice to work with if you have the right tools. I don't have the right tools.

Marginally better than a square cut:

Yep, did that with a power miter box. 16 inches up, one inch back.

Who needs plans, you got pictures:

The dangerous way to cut a 60 degree angle:

Clamp one to the master to get the angles to match

Drill holes for the screws of you will not get them in because they will break. Basically drill a hole the diameter of the screw and leave 1/2 inch at the bottom for the screw to bite into. Counter sink the holes or they will never sit flush. They make screw shaped bits for doing this. Wish I had one. . .
Don't zoom in too much on this picture:

I built scenery for theater in high school so making things that last is a bit new to me.
What did I say about gratification in your garage?

Continued. . .

 

[jazzmans]

The original legs were just metal legs with the same 'rough' dimensions less the triangle.

Maggies LOVE power, so feed them as much as you can. Mine get between 300 and 600 wpc.
A 20 amp fuse? I'd bet that's what caused the damage to the mylar, overdriven and overheated.

On the true ribbon models, the ribbons have a 1.5 amps fuse.

The sound of maggies is like nothing else, I agree. The only speakers I have that sound like them are my old infinity speakers with Emits and Emims (which are another type of planar driver, like maggies.)

You're likely ruined for box speakers forever.

 

[FireGuruMN]

My favorite stain:

Two screws up through the bottom and one at the top is enough.

Now I'm ready to set them up in the theater room.
I started with them widely spaced, pretty much at the side walls. That made them 15 feet apart and I was sitting 10 feet away. OMG that was awful. No sound stage at all. Just two speakers. No interaction at all. Back to Google. Magnepan say the spacing should be 60% of the distance from the speakers. So 10 feet away means 6 feet apart. Like this:

I would never put a normal speaker like that. But these are not normal speakers. Wowza! Lots of dimension and depth. Like an entirely different speaker. Hard to believe that position could matter that much.
But there is not nearly enough bass to fill this room (15x25) with all the deadening carpet and other surfaces. It's a bit disappointing. So I switched the amplifier (CX-A5000/MX-A5000) off of "pure direct" and over to "straight". That brings in my subwoofers (two 10" JBL powered by the MX) (because I have the preamp configured for "extra bass" which took for ever to figure out from the manual when I set that system up). So now I have lots of bass but it sounds awful. Back to the setup menus. I changed the speaker location to 9 feet. The subwoofers are directly behind the maggies at 10 feet in the setup menus. Incredibly that made the sound much much better. That has to be a super short delay for a 1 foot change in distance but everything matters. Google "time aligned drivers" someday. I'm not waiting this time.

I'm guessing that they are probably going to block my projector in that position though. I will have to find a different place for these I guess.

On to the next one. I ordered Tang Band drivers, 3 sheets of 1" thick MDF and a new table saw blade. Let the sawdust fly, I'm building SUG1-19's from scratch!

 

[FireGuruMN]

Maggies LOVE power

I forget who but someone said "the speakers sound great at about 200 watts and they blow up at 205 watts".

 

[jazzmans]

One of the keys to placement is AWAY from the side walls. You should be able to spread them out further and still sound great. I keep mine just under 3 feet from the side walls, and two feet from the rear wall.

I suggest you get tape and start marking placement, as tiny adjustments make a BIG deal in sound output.

I use subs with mine, the key to subs integration is turn the subs down and keep turning them down (both crossover and db) til they disappear.
I also have my subs directly behind my maggies.

I forget who but someone said "the speakers sound great at about 200 watts and they blow up at 205 watts".

I remember that phrase also, and think it might have been HP or at least in The Absolute Sound, long, long ago. I've only blown a fuse on my 2.5R once (the true ribbon model with 1.5 amp fuse), when I was trying for ultimate db.

 

[Blue Shadow]

I forget who but someone said "the speakers sound great at about 200 watts and they blow up at 205 watts".

That refers to the Ohm F not Magneplanar. Clipping will take out the fuse but they can handle more clean power. Some have 500-600 watts driving their three way speakers.

Staples. Hardest part of doing the repairs.

 

[maxhifi]

The original base for my (long ago sold) MG-IIB's was a piece of satin black painted 3/4" MDF, with a somewhat rounded shape, and two counter sunk holes to hold up the speaker.

Very nice work!

 

[FireGuruMN]

Found this on the interweb:

searching for "base" instead of "stand". That would explain the multiple holes in the bottom board. I have trouble imagining those are very sturdy. The frame is made of oak but still that is a lot of speaker to hold up with 4 screws. But I don't suppose there is a lot of frat parties going on in places where these are installed.

Why would the "right" label be on the front of the speaker? Is there a "wrong" label on the other speaker? Sorry. I do like the Magnepan logo/badge though.
Those would be a lot easier to build. . .

 

[swechsler]

Found this on the interweb:
searching for "base" instead of "stand". That would explain the multiple holes in the bottom board.

The original bases did not have those corners cut like that. I can't tell from the pic if they were original bases that were modified or if the owner built a completely new base. At any rate, I think your oak stands are a more elegant solution.

 

[goodolpg]

Interesting reading.
Thanks for posting.

 

[Blue Shadow]

The original legs were just metal legs with the same 'rough' dimensions less the triangle.

This is true for later Magnepans but the early ones had MDF bases to attach to the speaker. This ad shows a pair that appear to have been painted a gloss instead of the stock satin, nearly flat black. https://reverb.com/item/13181992-magnepan-magneplanar-mg-i-imp-vintage-speakers

MUG has a drawing for the MG-III mdf stands. The width of the II stand might be narrower to match the speaker, I didn't check. The MDF is half rounded all the way around the top. The MG-III stand has a Tee molding but the II did not to the best of my knowledge. http://www.integracoustics.com/MUG/MUG/pix/kendo/Magnepan Base.pdf

On the true ribbon models, the ribbons have a 1.5 amps fuse.

the True Ribbon Tweeter models, the 2.5/R and 2.6/R, the MG-III-series and up as well at the Tympani IVa have ribbon tweets with varying fuse sizes. Best to refer to the owner's manuals if posted on Magnepan's site for proper fusing or look at the input panel which has fuse information on it.

The sound of maggies is like nothing else,...You're likely ruined for box speakers forever.

FGMN has a lot of nice speakers he has rebuilt. I wonder how his DQ-10s compare.


As to setting them up, there are a couple things to keep in mind.
You noticed that separated they sounded like two separate speakers without a cohesive center image. at 6' apart there was a center image. You can separate them until the image breaks and then put the back together a bit.
The tweeters can go on the inside or outside, try it to see the result, making sure the tweeter is exactly the same distance from you on both sides for each set up. Then aim the speakers to have the tweeters shoot to the outside of the same side ear and then move the speakers to where the tweeters are aimed to cross just in front of the listener. Up to you, enjoying the speakers to find the best of those adjustments.

As to bass response, this will depend on the wall behind the speakers and the location of the speaker wrt that wall. Moving the speakers 1" closer or further from that wall can make a big difference. To start, you want to be able to walk from the listening area forward between the speakers and as you go, listen to the bass response. There will be peaks and dips in the bass. You want to have the listening position in a bass peak.

There is a lot to learn about speaker set up and Jim Smith, Magnepan National Sales Manager in the late 70s, for a couple years, has a book about getting good sound where he discusses speaker set up. We picked up the Magnepan line while he was the sales manager and the above info is from the time he came to the store to talk to us about the speakers with some added info from his book. http://getbettersound.com/index.php

 

[maxhifi]

Found this on the interweb:
View attachment 1859309
searching for "base" instead of "stand". That would explain the multiple holes in the bottom board. I have trouble imagining those are very sturdy. The frame is made of oak but still that is a lot of speaker to hold up with 4 screws. But I don't suppose there is a lot of frat parties going on in places where these are installed.
View attachment 1859313
Why would the "right" label be on the front of the speaker? Is there a "wrong" label on the other speaker? Sorry. I do like the Magnepan logo/badge though.
Those would be a lot easier to build. . .

Those cut corners are not original. The bases are more sturdy than they look though, I never had a speaker tipping incident. Mine had no logos on them, just slabs of MDF. The way they are shaped, and the enormous screws make sure they are strong and not prone to any instability. The real problem with maggies is what happens when you have a cat!

 

[Blue Shadow]

Magnepans didn't have logos years ago. Just the nameplate/connection panel on the back of the speaker except for the three way speakers with the outboard first crossover (bass and mid-tweet split).

They do have logos now and Magnepan can supply them to identify the manufacturer with their logo. Since I rock it old school, all the logos I have gotten to rebuild Magnepans have gone with the speakers to the new owner. I have my old school MG-IIIa and Steve's Tympanis in the sound room. I know who made em so I'm good for now.

 

[GD70]

This was a very enjoyable write up. It's amazing how forgivable the speakers are with not perfectly aligned wires between the magnet strips.
Magnepan notes in the repair kits, if there's small tears in the Mylar, to use scotch tape for the repair. When I rewired my SMGs, I had two small tears I repaired this way. I was able to slip a piece through and under the tear, then gently press the Mylar down against the magnet to make sure it stuck to the underside surface. Then put a piece of tape on the top surface. Worked perfectly.
My sock and side trim removal was exactly like yours. I did take note, and placed those thin trim strips to the side in the same orientation as they were removed so the original staple holes would line up later for reinstallation. Also marked them with tape "Top-A", "Top-B" etc..., I'm anal like that and wanted reassembly to be as easy as possible.
Luckily, my socks are brown, stretchy material, so I had no difficulties reinstalling them.

Like you, my first listen was a jaw dropper! I had planned to fix-n-flip, but after that first listen, nope. At that moment, I understood Magnepans and why they have such a loyal following. No box speaker can do what the maggies can. I've got some decent speakers that I'll never sell, and maybe I'll sell the SMGs for a slightly larger set but for now, I'm satisfied.

Congrats and hope you enjoy them for years to come!

Cheers, Glenn

 

[cpu_]

How similar are these to the MG2.6R? Mine need repair. Apparently delamination has been visited upon them after almost 20 years of glory.

 

[Blue Shadow]

There are the same except the 2.6 has ribbon tweeters that are attached by screws vs. the mylar and thin wire of these IIs.

So you just have the woofer to do. Easy. Tweeters are exchanged for new from Magnepan for about c-note a pop plus shipping both ways.

If you are going to dive in for a repair, start your thread on them as the speaker isn't an MG-II.