Has anyone seen or run any response plots on 800 series drivers with the 511 horn? I'm interested in the limits of the bottom end response. I have some aluminum 806A and sybiotik 807 drivers from my Valencias and VOTTs that I wanted to try with my Belle Klipsch as a mid horn with a 511. I'm aware that the Altec spec pages say that the frequency response of the drivers goes down to 500 hz. But does anyone think that I could realistically squeak 400 out of either horn driver combo or would they poop out at 500? (806/511 or 807/511). Alternatively, is there risk of driver damage if I try to push them that low? It would be used with passives and a 12 db slope. Thoughts are appreciated.

Carl.