Curious about both of these drivers... leaning towards the F6's for MB duty now.. was going to do an 8", but going to stick with the 6.5" size...

I have owned both the E650 and GB60 drivers, as well as a few others that are comparable...

I felt the E650 was definitely lacking in the midbass frequencies compared to the GB60's..

For this reason I will likely go back to GB60's, but I'm really intrigued by the F6's. I guess I will just have to get a pair and try them out... I'm sure the detail and tonal accuracy is likely similar between the GB and the Vipera line, but I'll have a bit more oomph, especially in the 55-200hZ area... I'd be running them from 50-400 or so... still uncertain about keeping them IB in my doors or having a custom sealed enclosure fabbed up for them there...

Anyway, thanks for the review!