| T. Bone RM-700 vs. Nady RSM-4
Just had a couple of RM-700 ribbon mics on the bench today and made an interesting discovery - these mics use an "offset-ribbon" placement - just like the Royer R121. That is to say, the RM-700 ribbon is offset toward the front of the mic. This provides higher SPL handling on the front side and a brighter sound on the back side.
This is fascinating to me because all the RSM-4 mics I've seen (same "lollipop" style as the RM-700) use a symmetrical ribbon placement to avoid running afoul of the Royer patent. When it was first introduced, the RSM-5 ribbon mic used a "backward offset ribbon" in an attempt to avoid infringing the Royer patent. But this was recently changed to a symmetrical ribbon design as well.
So, for all you Europeans with RM-700 mics - there's a good chance you've got the Royer offset ribbon feature! Just check the frequency response of the front vs. back (say "Shhhhhhhhhhhhh...., make a recording on both sides, playback. Do not do this in real time in headphones as the acoustic signal reaching your ears will confuse the issue). If the back side is brighter, the ribbon is offset.
Btw - the stock RM700, like the Nady RSM-4, uses a 6 micron ribbon (which I upgrade to 1.8 micron in my mods) |