Attenuating Louder Tree Frogs

Debbi would like to bring-out the subtler, quieter calls of Reg Legged Frogs in a recording where Pacific Tree Frogs are singing much louder. If equalization proves to help, she may decide to work on learning some EQ skills. To get the ball rolling, I've made a QuickTime Movie with four sound clips with my first attempt at EQ and EQ with an effects plug designed to reduce sibbilance. Here's description of the four clips in the movie:

(1) Debbi's original mono field recording.

(2) The recording equalized with 28 bands of parametric EQ using Eqium. I primariy addressed the raspiness of the tree frog calls in the upper mid-range, exaggerated high frequencies and I tried to address a mysterious very low frequency throbbing sound (idling truck?).

(3) The above equalization AND the "De-Essing" plug in Logic Audio (mild high hat setting). This plug was set to apply compression around 2K Hz.

(4) Debbi's equalized sound file she made in Audition.

I tried a number of ways to reduce the very low frequency throbbing in the recording without much success. I elected to leave it as is rather than eliminate it with a high-pass filter.

What do you think Debbie? Which of the four clips best serves your purposes? Rob D.