That's my rig (if can use that word):
Edirol R-09 > SP battery box (of course, no bass roll-off...) > SP-TFB-2 mics. Important: I use the mics ouside the ear. I've just got a brand new pair of Microphone Madness HLSC-1 (Sennheiser Driven) mics.
I know this is slightly off topic but I feel understanding how the low end gets on the recording in the first place helps avoid post production EQ/HPF'ing.
I think much of your bass is the result of using omni microphones indoors. Sound gets to your ears in
three ways: direct, reflected & reverberant. With omni's the later two contribute more to the signal and reverberance more so of the two. Also reverberant sound favors the low end as high frequency sound attenuates faster.
Have you tried running "in your ears" or using a Jecklin disk? I think this may help reduce the amount of reverberant sound getting to each mic and improve the ratio of direct to reverberant.
Do you have the basic battery box or the one with level control?
I can't seem to find any information on the R-09's input impedance nor for the load impedance of the battery/SP-TFB-2 combo. Are you running line in or mic in? Is the bass you get clear or muddy? The latter could be the result of an imput impendance mismatch.
You're absolutelly right in your remarks.
I normally running Line In. The bass is pretty much on the clear side. In this particular case, even at the very moment I was taping, the bass was overwhelming.The venue itself has great acoustics, is a brand new theatre. To my ears, the bass player or/and the soundman were excited about the great acoustics and push to much the bass EQ and Volume. Bass was very, very loud.
My Edirol takes care of the level. No level on my battery box.
The omni thing is what made me move to the Sound Madness HLSC-1 mics (cardioids). Also, I got another battery box, this time with Bass Roll-Off. Yes, I've been told that I will not need roll-off with those mics, but I think is always good to have options.
I was not using the mics inside the ear because doing so you end up with a great sounding headphgone sound, but sometimes terrible when listening with speakers. Besides, it's awfull to play marble statue the whole show. You just can't move your head if you don't want to mess up your recording.
Excuse my lack of knowledge, but what exactly do you mean with "impedance mismatch"
Thanks