Who plays instrumental songs, bass down tuned?

Well, since I discovered Animals As Leaders, I look different to instrumental songs. Not that I hated it or something, but for me it was something different then songs that had vocals in it.

Okay, AAS doesn't have a bass player, but they do tune their lowest 2 strings of their 8 string guitars, down with a whole step ( F# B - - > E A).

I have to say it's very cool and all, and I've been listening more instrumental music on the internet, with a bass player mixed in the song, who down tuned his bass to Drop D, Low A, half step down, whole step down etc. etc.

So who of you does some instrumental stuff with his / her bass down tuned? Can you post some examples as well?