Well, I finally tried them first time last week with the -15dB switch ON - yeah I know I bottled out and took the easy route, but I needed to be safe rather than sorry, and it worked (I love these mics), but not in the way I was expecting.
Taping at front stage, fairly loud amplified post-punk band (drums, bass, guitar, pretty standard), but PA stacks were hanging above and behind me, so I was not getting much of that. Recorded on R-26, P48 XLR's in, lowest sensitivity setting (+4dBu), levels set at 50 which is half way. Very much ste@lth situation, couldn't check my levels even once, and no support band, so I just set the recorder rolling, put it away, and hoped for the best, hence the -15dB pad ON.
Result? Peak levels of -28dB!!! I was amazed it was so low as I had previously taped half a dozen shows from stage front with Nevaton MCE400's with the same recorder sensitivity and level settings and always peaked at about -10dB. I was also taping with a pair of B3's and got exactly the same result I had expected for them (peak at -9dB), so it wasn't a quiet show by any means.
MCE400 sensitivity is about 10mV/PA, so the 15dB switch must change the CK930 rated 32mV/PA to something less than 5mV/PA??
So, Page and DSatz were both right (of course....), I didn't need to use the -15dB switch. Luckily I was taping in 24 bit, and it was a fairly noisy show, so upping the levels and then slapping a limiter on at the end did not appear to induce any noise, not that I noticed anyway. So worked out well considering first attempt, better that than bricking IMO. No doubt I would have got a better pull (in this show at least) with that switch OFF.
But, next time, what do I do?? (bearing in mind next show I might well be catching the PA stacks as well as the stage):
(1) Turn the -15dB switch OFF;
(2) As (1), and lower levels on R-26 to 30 or 40 (5 to 10dB level drop)
(2) Leave it ON, but increase the sensitivity on the R-26 by 12dBu (or 18dBu?, or more?)
(3) Keep all the settings the same and up the levels on the R-26 - up to 70 would add about 10dB gain. Don't know how high is safe.
My inclination is to knock the -15dB to OFF, but just worried about hitting a loud PA-driven situation.
Any more advice will be gratefully received.