Modify the Shure SM57 Microphone

[ciminosound]

[quote author="Flatpicker"][quote author="fucanay"]CJ, You are a strange cat...[/quote]
Yikes! :shock:
He seems normal to me, lol! Strange or not, I must join in thanking him for always putting in the hard work while providing more humor than the comedy channel. Hats off to CJ! :green:[/quote]

Normal is a relative term and a matter of perspective....

:green: :sam:

 

[CJ]

OK, I could not resist further investigation on the 57.

Man, you get your money's worth with this thing, thats for sure.

http://vacuumbrain.com/The_Lab/TA/Microphone/SM57/57_cap1.jpg

You see that little wire on the yellow tape?
Thats the voice coil wires!
They got ripped up when I took this thing apart, so beware!
Unsolder it first. It gets soldered to that termimnal plate.

The lid was pretty hard to get off.
I had to clamp the mag assy in the vice and go after it with the channel locks.

Here's a close up of the capsule. Those red dots glue the voice coil ontothe diaphram. I do not think there is much room for modification in this dept.
I kinda wanna take the rest apart, but what if I mess up the gap?
Note mag gap for coil, etc.

You might try the mic without the foam, or the cover, some folks say it sounds better, seems minor. Souping up a sparrow hawk does not make an eagle.
But maybe you will notice an improvement.

You can pop out that cadnium washer, but after that, it looks like they swedged the heck out of the mag assy to keep it from moving during a stage slam.

There is a rubber shock thingy inside the gray housing.
Thats what was tugging at me when I was trying to rip the capsule assy apart without undoing it properly. But thatz how we roll at the Lab, right?

 

[soundguy]

madman.

[quote author="CJ"]You might try the mic without the foam, or the cover, some folks say it sounds better, seems minor. [/quote]

I bet it sounds way different without the metal grille and the foam crammed up against it.

If you use it without the plastic vented piece I would think that you'd have a different polar pattern or at least a different frequency response along the edges of the polar pattern. Cup your forefinger and thumb around the vents and listen to how the frequency responnse changes, its logical that the same thing would happen in reverse if you removed the baffling chamber entirely. I havent tried that, so Im just speculating but seems logical enough.

dave

 

[okgb]

It s worth noting that the 57 can sound different when loaded by different
peramps with transformers or x-formerless

I m in the anything but a 57 for gtr camp , although a 57 with a cheap
ribbon mic combo is an easy to big sound

regards Greg

 

[rodabod]

[quote author="CJ"]
Here's a close up of the capsule. Those red dots glue the voice coil ontothe diaphram.

[/quote]

Those red dots are glue? Jesus, that thing loos a bit stone-age compared to most German and Austrian mics.

I think I may do an A*KG D12 capsule disassembly as it is modular, and even the diaphragm can be removed and refitted (it is not glued).

[quote author="soundguy"]madman.[/quote]

Indeed, he's a bad-ass.

If you use it without the plastic vented piece I would think that you'd have a different polar pattern or at least a different frequency response along the edges of the polar pattern.

Yes, the plastic senonator cap has a big effect on the frequency response and is there (usually) to try to extend the response. You could tape some of these holes shut to hear the difference.

 

[Flatpicker]

[quote author="fucanay"]I hope I didn't offend with the strange comment...[/quote]
I meant that jokingly like "Yikes, I must be strange too", not like "Yikes, you said something offensive." :wink:

 

[CJ]

This is probably the best dissection as far as mic model.
You get the most bang for your buck.

Used 57: 50 bucks?
Mic Value Rating: 98%

98/50 = 2 on the take-apart- scale.

After this, I will have to pay more to learn about lesser classics.

Talk about weird, I just saw the Devils Rejects last nite. Thats pretty weird.

This is a 250 dollar mic for $89. How? The tooling and R&D has been payed off for years. Parts have been mass produced for pennies. Labor is cheap down south. If Shure were to come out with this mic today, it would cost a bundle. No wait a minute, I forgot about China. Wonder how soon til......

Anyway, I came away very impressed with this mic. It is built like a tank where needed, and delicate where needed. Everything is shock mounted, the capsule used dots of glue to avoid mass, the voice coil is wound on a swiss hot wire machine. There is no coil former. This cuts down on mass and allows a thinner coil for the critical gap clearance.
Special wire is wound on a precise mandrel. Remember, the gap in this thing is probably microns. That's why the mag assy is so beef. If something moves the slightest bit, your coil is going to rub. Anyway, after the coil is wound, heat is applied. An ingrediant in the wire turns to glue and the coil holds it's shape. Nothing new, I think this is how yokes for TV's are done. Same swiss machines are used by sony, koss, etc, as I mentioned a while back.

The xfmr is not a thing of beauty, but it probably has the plenty of response for the freq band produced by this mic. It might be built to take a an extreme range of input levels also. Shure is a model company as far as what you strive for in a bussiness. Great product, excellant engineering staff, they listen to their customers, they know how the product gets appliedc in the field, great website, consitent quality, thats why they have been around so long. They see that 57 in front of the Marshall and they engineer accordingly. That could be the reason for the xfmr construction, they knew it was going to get hit a lot harder than expected.

I am going to measure the inductance of the capsule coil.


Hey, I didn't throw up my KFC! Alright!

That screw that runs thru the capsle has my attention. I wonder if its a gap adjustmen or something? They might calibrate these to put out the same level by moving the magnet in or out of the coil, just like the slug in a tunable torroid. A simple mod might be to just turn that screw.

There is plenty of room for a xfmr bypass sw in the lower mic body. No need to mount anything outside, unless you want a xfmr switchbay type of thang.

 

[CJ]

Voice coil:

223 uH
DCR 11.05 ohms
Wire: dot 003 > dot 0035 = #40 ga

Don't know which way mag is pointing, forgot my compass.

 

[Flatpicker]

Good gravy, man! Take a break and have a round! :sam:

 

[CJ]

Yeah, I'm burnt on the 57.

I think the cheap core is to roll the bass so that when people crowd that mic, they don't "proximity effect" that core into oblivion.

 

[tony dB]

CJ, you're simply the best, man!
Really !! :thumb:

How much time did it take you to get this done? Including your super reports overhere I mean :shock:

 

[pucho812]

CJ thats was cool. :thumb:

 

[Svart]

i've never seen this thread until today and although i simply hate the sm57 I still own one. i also own an M201, which trounces the sm57 like it was made by fischer-price, but anyway...

I did some modding of the sm57 a while back before this thread even started and I did both the trafoless mod and the grill mods. both I say are a waste of time unless you just want to see what happens.

grill mod: no grill or missing foam. sounds honky and thin due to the lack of muffling. don't even try it on vocals without the foam.

trafo mod: low low output. not much gained in the long run. yes the freqs are better but not up to the standards of a used audix D series or M201, both of which can be had for around 100$ if you choose wisely.

if you are just looking for a good mic for snare then go mc012. cheap, easy to mod.

just my .02$ but if you find something out I'll be happy to hack my 57 in the name of science but until then I have other projects to get to first.



:thumb:

 

[mikep]

[quote author="Svart"]i also own an M201, which trounces the sm57 like it was made by fischer-price [/quote]

I have a M201. especially love it on electric guitar. but on snare, I dunno. rarely does it work better than the cheesy 57. the 201 has more "pop", less ring, sounds almost gated compared to a 57. I *think* this is because the 57 is dynamically compressing. distorting the transient, or something. it spreads the sound out, makes it wider, a little blurrier. I like that.

[quote author="Svart"]
if you are just looking for a good mic for snare then go mc012. cheap, easy to mod.[/quote]

yeah, not a bad recomendation in general, but for general purpose snare duties, nahh. If you want a nice condenser on snare save up for a KM84 :wink:

 

[Jeremy H]

Hey Guys,

Just wondering if what has been expressed in this thread would also basically apply to the Shure 58?

Or am I missing a fundemental topology difference between the two mics?

 

[soundguy]

[quote author="Jeremy H"]Just wondering if what has been expressed in this thread would also basically apply to the Shure 58?[/quote]

yes.

dave

 

[higginsrob]

I already ripped up my SM-58 and the mod is exactly the same.

CJ inspired me to pic up a UTC O-8, I'll drop that in when it arrives.

CJ, hows that sound by the way?

 

[CJ]

I don't know yet, I have to test the 0-8 as it was a gift for dissection.
I keep forgetiing to writes tuff down, people use their real names on all the boxes that arrive on my doorstep about once a week, so I lose the forum name of the person, I am darn sur that Pmroz sent that, although he has been busy as of late.

Funny, I had so much fun on the 57, that I went into Guitar Center and asked about the price of the 58 that was staring at me in fear from the bottom of the showcase glass. The guy said "You don't want the 58, heres a Sunheiser for the same price with more mayonaise and mustard than the 58."

I said no, it has to be That one. :twisted: :twisted: :twisted:

I figured out the highs on the transformer. The coil is wound purposely with leakage that rolls off the top to prevent feedback. So tghe engineers knew what they were doing. The xfmr is built cheap on purpose.

Small core- low end roll off for contol of proximity effect with mic crowdfing vocalists ( why does everybody love to crowd the 57?)

Leaky coil struture- high end roll off for feed=back control

looking forward to the transformer mod.

0-8 should will be beter due to non dc core.
wonder what amorphous would sound like in a mic?

 

[mathflan]

HI!


I bought a SM57 used for 50 euros, 60$.

But I think that The capsule is died, I guess I have a loss in the medium and treble.
Do you think it's possible to find and replace the capsule?
Is shure sell capsule of their mics??

thanks

very insteresting tread!

 

[CJ]

Send it to Shure or just buy another one and save the hassle.

Beware, some freak sent on a 564, or whatever the orig was, anbd they kept that and sent hima new 57!