RSM-2 owners of the world (unite and take over)

[lansingxcore]

hey. picked up a pair of those nady ribbons on e-bay. they are supposedly in brand new condition, having been display models. a friend and i did some semi-scientific tests, using a white noise generator, of their frequency responses. the results are here:

http://www.lansingscene.com/studio/images/mic283.jpg
http://www.lansingscene.com/studio/images/mic289.jpg

since one of the mics is slightly louder at all frequencies, i believe it may have been a tad closer to the speaker, by accident. i'm not sure though.. they may just have uneven outputs..

they are serial numbers 1592411283 and 1592411289. what i would like to do here is create a sort of database of rsm-2 mics, to try to make evaluations of quality control in different batches, etc.. for the record, these tests were about 6" away from a mackie hr824, pointed right between the woofer and tweeter, through an FMR RNP. also, in terms of overall Db output, they were pretty much exactly the same as my friend's beyer m-500.

discuss. also, i may cross-post this at tapeop..

 

[mshilarious]

they are serial numbers 1592411283 and 1592411289. what i would like to do here is create a sort of database of rsm-2 mics, to try to make evaluations of quality control in different batches, etc..

What for? Other owners won't be able to duplicate your test rig. Also, over time, some owners will abuse their ribbons, causing them to sag or tear, and ribbons will be replaced, which could change the sound considerably.

Regarding your graphs, ribbons have a severe proximity effect (which is often a good thing, musically speaking), so if the distance to the mic is even a little different in your two tests, the bass response could change materially. I think I'd test at around two feet where placement is less critical, both in terms of mic-speaker distance, and relative distance between the woofer and tweeter. It would also help to calibrate your test rig with a measurement mic first.

 

[Brent Casey]

Thanks. Now that song is stuck in my head.

 

[Flatpicker]

Thanks. Now that song is stuck in my head.

Yeah, I hear that one all over the radio dial, lol!

 

[lansingxcore]

What for? Other owners won't be able to duplicate your test rig. Also, over time, some owners will abuse their ribbons, causing them to sag or tear, and ribbons will be replaced, which could change the sound considerably.

Regarding your graphs, ribbons have a severe proximity effect (which is often a good thing, musically speaking), so if the distance to the mic is even a little different in your two tests, the bass response could change materially. I think I'd test at around two feet where placement is less critical, both in terms of mic-speaker distance, and relative distance between the woofer and tweeter. It would also help to calibrate your test rig with a measurement mic first.

that's exactly the response i got on the other board. and of course, you're right. look, i just wanted to get a general consensus going about this mic. i have no way to calibrate the chain we used, it's not even my setup, it's my friend's. it's not scientific, i called it 'semi-scientific' because we attempted to keep all things equal between the two mics. this is the same way he gets a general idea of the frequency response of all his mics, and he's the second-in-command at a $100/hour studio with a neve console. my thinking was, if somebody gets a mic with a dramatically different shaped curve, using a similiar testing setup, then we could reasonably assume that there may be some discrepency in the performance of those two mics. if we see a trend, well, people can draw whatever conclusions they will. i'm sure an oktava ml-52 has a noticably different curve, for instance.. probably nowhere near as good on the high-end. i just want to try to put people's minds at ease about nady's quality control, by putting them to some sort of (hopefully somewhat universal) test. of course, people would have to do the test before they used/abused the mics much.

in the coming days, i'll try re-doing the test with my monitors (a less universally trusted model, the wharfedales) at the same distance at first, then two feet out like you suggest. seems to me like the room would come more and more into effect the further out you got. but anyway, i don't have the same program he used, nor the ability to take screen captures, so i'll have to just describe the results.

p.s. i'm gonna be sticking these mics right up to the grill of a guitar cab.. so i think having a good idea of the curve WITH proximity effect wouldn't be bad.