Carvin CM90e Mods

[Micter]

I had (well still have) a pair of Carvin CM90e's laying around. Basically they were just about worthless in their stock state. I started looking at the capsule housing and noticed the cloth around the inside of the housing. Got rid of that junk. I also noticed the foam in front of the capsule. That can't be good! See ya! Then I tested the mic and noticed it sounded like it was more open than before but had a wierd resonance. So, I look at the capsule housing again remembering that the capsule is set too far back and decided to chop off the capsule housing by about 1/2". I pulled out the grill material all the way around. I pulled out my trusty dremel with a cut off wheel and chopped off the last ring. (there are 5 rings on the stock units) Then I take them to the disk sander and straighten everything up. I used the two rings as a guide to shorten the screens (both side screens and the front grill) I glued the front grill in place flush with the capsule housing and re-installed the wire mesh on the sides. Now the capsule sits about 1/8" from the tip of the housing. The mics are very usable now. Funny how just some simple things that didn't even cost any money can make a junk mic usable.

I need to get some batteries for my camera so I don't have any pics.

"DO NOT TRY THIS IF YOU AREN"T MECHANICALLY INCLINED"

http://www.carvinguitars.com/manuals/CM90E.pdf

here's a spec sheet of the stock mic for reference

 

[Mike_ggg]

I know this was posted over a decade ago, but I have a couple of these CM90E mics that must be 25 years old. They are the older design, but basically the same mic. From what I’ve been able to find on line, the capsules in those old ones aren’t that bad. They were made by one of the major microphone manufacturers and it was well before all the junk and copies started coming out of China. I tried them as some overheads on some congas and bongos and they sounded OK, but not great. Mine didn’t have the cloth in them, but I did remove the foam on the capsule and used a dremel to cut and shorten the cover to move the capsule right up close to the screen and eliminated that solid metal ring that was in front of it. I trimmed the screens and glued them back together and just did a recording test with all the exact same setting as one I did last night with the stock mics that I already removed the foam from. It made a huge difference Listening to the before and after. For what I’m using them for in an XY configuration over the hand drums and using a D112 at floor level to pick up the bass from the congas, they’ll do fine on my current project.

Thank you, Micter, for your analysis. You were spot on with the foam issue and the capsule being too far back and picking up a weird resonance caused by that 1/4“ or so of a short tunnel surrounding the capsule. These were mediocre at best before and now they actually are usable and sound so much better and I’m pleased with the tracks I just recorded with them. I have some better mics, but they’re all being used elsewhere and this saved me from having to buy or borrow new mics to use for this. I’m very happy I found this mod suggestion.