[mlantinen]

Thanks for the responses everyone.  
 
I'm getting some conflicting info though.  
 
Is the coil supposed to be glued to the diaphragm though?  I took a look at some of bilavideo's pics of a murdered driver and it looks like the voice coil is attached to the bottom of the diaphragm.  If that's the case I don't think it's attached to my other driver either...poking at the diaphragm through the holes it doesn't seem as though the voice coil is moving with the diaphragm, so maybe it's detached too.  Both of the drivers very well could have been jostled around alittle too much while transporting them from the house to the garage, knocking both diaphragms loose from the voice coil.  Talk about s**t luck.  
 
Mr. bilavideo whenever you get a chance please confirm the above.
 

 
 

 

[mlantinen]

Well here's the housing at least.  Not polished yet, but pretty close to done.
 

 

[tisb0b]

Looking very nice, have you considered adding a jmoney headband?

 

[pbandstefanwich]

I'm not an expert at driver repair by any means, but I've taken apart and repaired a couple cheaper drivers so far. Never tried taking apart a driver as expensive as RS1s though. Anyways, I do know that the voice coil is definitely supposed to be attached to the diaphragm. You could try super glue. I've had that work for me before. Although, I'm not sure if Grado originally used any sort of special glue. Also, I know that when they re-cone loudspeakers some people like to put a very small voltage across the voice coil when they're remounting the spider and diaphragm. This creates a magnetic field and ensures that everything gets lined up perfectly. I believe they change the direction of the current when mounting the spider and diaphragm to get the right tension, but I could be wrong. Not sure if this would apply to headphone drivers too, but it's something to keep in mind if you don't think you could get the voice coil lined up in the center of the diaphragm. Probably better for you to try and get things lined up by hand first though, to avoid any risk arising from putting too large a DC voltage across the wires.
 
Another thing, the outer rim of the diaphragm is supposed to be glued to the plastic driver base.
 
This is what I've noticed from the drivers I've looked at. It is possible the older Grados used a different design, but I highly doubt it. Dynamic headphone drivers seem relatively simple and a relatively standardized design that hasn't changed a whole lot lately.

 

[Mercuttio]

Honestly? At this point I'd slow things down, and not touch that driver before doing some experiments on an SR60 driver. That's the cheapest way you'll figure out exactly how they're supposed to be.

 

[Bilavideo]

Thanks for the responses everyone.  
 
I'm getting some conflicting info though.  
 
Is the coil supposed to be glued to the diaphragm though?  I took a look at some of bilavideo's pics of a murdered driver and it looks like the voice coil is attached to the bottom of the diaphragm.  If that's the case I don't think it's attached to my other driver either...poking at the diaphragm through the holes it doesn't seem as though the voice coil is moving with the diaphragm, so maybe it's detached too.  Both of the drivers very well could have been jostled around alittle too much while transporting them from the house to the garage, knocking both diaphragms loose from the voice coil.  Talk about s**t luck.  
 
Mr. bilavideo whenever you get a chance please confirm the above.
 

 
 

 
Ah, the nightmare of the Grado driver autopsy.  It's like looking at what was left behind by a Salvadoran death squad.
 
The coil is definitely glued to the diaphragm.  It is not, however, glued to the magnet, but fits within the groove between the magnet and the magnet plate.  It's possible for it to be pulled loose by a strong hit of bass or by a gust of wind pushing through the open backs.  There are, in fact, mysterious driver failure issues that come up, stuff that would make you want to jump off a bridge.  I've had it.  I was working on a pair of MS1s, had everything ready to place into the box and then one of the drivers failed, and for no apparent reason.
 
Dropping a driver will not, in and of itself, kill it.  You would have to puncture the diaphragm or knock out the voice coil or really smack it hard enough to dislodge the magnet, which actually has fairly exacting tolerances in order to preserve that perfect groove between the magnet and the side of the magnet plate.  But to dislodge the magnet, you'd really have to hit it hard, much harder than simply dropping it.  The magnet isn't glued into the plate.  It's held there by magnetic force and that force is finger-pinching powerful.  Having played in that particular sandbox a time or two, I can tell you that the magnet is not casually stuck there.  Removing it takes a bit of effort; putting it back without getting bitten takes a bit more.
 
The one thing that bothers me about this picture is the voice coil leads.  Unless they're insulated (which they can be), their position, relative to one another, raises some questions about whether there's a short circuit in the system.  You can't see it from these autopsy pictures but if you scroll back far enough, you'll see what I'm talking about.
 
The driver is Fred Flintstone simple.  You've got a diaphragm, a voice coil, a magnet, a magnet plate and a plastic frame for the diaphragm.  You can't break the frame.  You can only rip the diaphragm (or crinkle it, but crinkled drivers still work).  You can burn up the voice coil or knock it loose.  You can demagnetize the magnet.  There's not much you can do to the magnet plate, other than drill holes through it, which I've done (and wouldn't do again).  
 
If you're not getting any sound at all, the usual suspects include:
 
1. A burned voice coil;
2. A misaligned voice coil;
3. A short circuit between the terminals and the voice coil;
4. A demagnetized magnet;
5. A problem in your cable that has nothing to do with your drivers; and
6. A problem in your rig that has nothing to do with your driver.
 
There's also Yahweh and his ant farm.  (See Job.)

 

[mlantinen]

 
 
Quote:

The coil is definitely glued to the diaphragm.  It is not, however, glued to the magnet, but fits within the groove between the magnet and the magnet plate. 

Thanks Bill and pbstephanwich.  
 
So Bill, is the outer rim of the diaphragm supposed to be glued to the plastic base or is it supposed to float?
 
How would I know a magnet has been de-magnetized?  Do you hold something metal up to it?
 
How would I know a voice coil is toast or if there is a short circuit?  Do we just assume this after we've tried everything else?

 

[spork42]

The diaphragm definitely does not float; sorry if my response before was a bit vague, I meant that the diaphragm needs to be able to move in and out with the coil, not that it floats in the enclosure.
 
The diaphragm is either attached with glue along the edge, or is held in place be the housing holding the edge down when assembled; I do not know which, but it looks like glue residue is around the edge in the above picture.
 
Whatever glue you use, use it sparingly around the coil as you ideally want to add as little weight as possible to the diaphragm while still having the two hold to each other throughout play.

 

[pcf]

Maybe Rhydon can help?
 
Send him a mail:
Rhydon@symphones.ca
 
 
 

 

[mlantinen]

Thanks again Sporky!  Yes, that would make sense to me.  When I opened up this driver, the edge was not glued down, so I'm confused how it could have come unglued from the edge as well as unglued from the voice coil.  I guess it's no matter since what's done is done. 
 
Do you know will any sound be made or movement or will the voice coil visibly move at all if the diaphragm is not attached?  The reason I ask is that I resoldered the cable to the mutilated driver without the diaghragm attached and plugged it in to see if there was any sound or movement whatsoever and there was absolutely nothing.  Should it do something or no? 

 

[mlantinen]

Ok.  I also confirmed with alphones who's picture was found in bilavideo's SR-60 Mod thread, that you can use contact glue to re-attach the voice coil as well as the outer edge of the mylar.  I will be trying this tonight. 
 
I also read on the Google that if you place a metal object up to the driver magnet and it pulls toward it or sticks, then obviously you have an ok magnet.  So I don't think that is the problem.
 
Also, I looked at pics of burned or damaged voice coils from speakers and it's pretty clear that you'd be able to see some sort of blackened area from the burn.  Mine looks just fine. 
 
So if re-attaching the mylar doesn't work, then it's got to be a broken voice coil lead under the plastic or under the terminals/tabs or a burned out tab.  In that case, I will be doing more homework.   

 

 

[spork42]

The coil must be attached to the center of the diaphragm to move it, and the diaphragm's edge must be held in place, before any meaningful sound will be produced.
 
The coil should, however, still move in relation to the magnet when any current is put through it when it is placed in its groove, but this movement will be very slight, and I would not recommend it unless the diaphragm is attached, as otherwise there is nothing stopping the coil from going somewhere it shouldn't (up) and possibly damaging it.
 
As for what may have happened to the glue... did you apply any heat in order to remove the enclosure?  It is possible that the glue was melted at some point during disassembly.

 

[mlantinen]

Hey Sporky, do you know how I could tell if the terminal tab was bad?  In theory I should be able to remove the old solder with a solder sucker to look at the tabs right?  I would imagine that I could risk tearing some of the think metal tab off with the solder though.  Also, even if the tab was damaged in an area, wouldn't the conduction through the solder and to the remaining undamaged tab area allow for current to pass properly? 
 
Does anyone know how to replace these types of terminal tabs if one is damaged.  I've been searching and searching but I can't seem to find an answer to this. 
 
I've just gotta think that assuming the magnet and mylar diaphram is fine and the voice coil isn't burned then these should be fixable, even if I have to remove the tabs and dig out the plastic to get at the voice coil leads to repair them.  I've been reading up on speaker repair and it seems like every post I read has a successful speaker repair story.  Voice coil leads can be resoldered, some magnets can be re-magnetized, voice coils can be replaced (I know my voice coils could not though).  Even if my mylar diaphragm was ruined I could rip one from an SR60 if I needed to I would think.
 
With all that said, it blows my mind that at first look, all Grado drivers have the same parts, yet can have drastically different sound depending on the density and strength of the magnet, I would suppose.

 

[pbandstefanwich]

I'm not sure how to test the terminal tab directly, but it would be easy to do a continuity check of the voice coil. If you have a multimeter, you should measure the resistance across the two solder points. If everything is making a good connection, you should measure about 32 ohms (if the vintage grado drivers are about the same as current drivers). If you measure 0 you have a short somewhere, possibly in the voice coil leads. If you measure infinity, then you are not making a connection somewhere, likely around the tab area because the leads looked all intact from your previous picture.
 
Actually, it's not just the magnet that makes a difference in the sound. The diaphragm and the coating they use makes a huge difference. Look up the thread on the diyaudio.com about the enabl process for loudspeakers if you get a chance. It goes to show how much of a difference the coating makes (granted that involves applying a coating at specific points on the driver, but it still shows that what you do to the diaphragm can make a huge difference to the sound). Also, I believe the current form of the Symphones Magnum mod basically strips away the coating that grado uses and they apply their own proprietary coating the to the diaphragm, and that improves the sound too (I know they were doing straight replacements of the drivers before, but I think they changed their method to use the existing driver but with a different coating). That being said, you could definitely replace the diaphragm with an SR60 one, but I'm not sure how exactly the sound would change.
 
Also, keep in mind that repairing a loudspeaker is much easier than repairing a headphone driver. Neither are easy, but easier done on a loudspeaker due to how large the components are and a lot of them are meant to be replaceable, unlike on headphones (can't say I've ever seen replacement headphone diaphragms or voice coils for sale!). Seems that when a headphone driver goes out, people generally just replace them. Whereas on a loudspeaker some people opt to repair them or have a professional recone them. I would try and avoid playing with the voice coil leads as much as possible. They're very fragile and would be a real pain to replace.

 

[mlantinen]

Thanks pb, yes, it's definitely a last resort dealing with the voice coil leads and the tabs, but I wanted to be somewhat prepared if gluing the mylar back on doesn't work. 
 
Thanks for the tip on the multi-meter.  Would you put one of the testers on the coil and the other on one of the terminals/tabs, test it and then switch to the other terminal/tab. 
Edit: I just read that you would put one lead (pos or neg, it doesn't matter) on one terminal and put the other lead onto the second terminal, set your multi-meter to Ohms and then read it.  Sounds easy.
 
I picked up some magnet wire from Radio Shack but I'm sure it's not nearly thin enough if I needed to use it for a splice job.  I've read that you can unwind a loop or two from the voice coil if you need extra lead wire, but that sounds quite impossible with how thin this stuff is.