I doubt the Oktavas would distort at a concert SPL. I have a pair of Oktava MK-012s, I use in the studio sometimes. They are great on some applications. I insert the -10dB pad if I'm close miking a cymbal or something, but they should have no issues recording below 125dB, which would be painful to our ears.
Like the rest suggested, I'd leave any filtering off and filter in post.