What does one look for in picking a mid for dipole use? I’m sure x-max is important due to the lack of damping from an enclosure as well as providing headroom to allow for boosting the low end that is usually required in such designs.

Are there any other things to consider? In my specific case I am more concerned w/ the lower end of the operating range of a 6ish inch driver to use in an array. These will be used w/ a very low crossover point to the tweeters and a sub to cover the low end.

I have the opportunity to pick up some Audax 6.5” mids at a really good price. I was considering using them if there is nothing obviously wrong w/ the specs. The Qt is kind of high at .8
Fs= 60 Hz
Vas= 17.62 liters
The x-max is a little limited at 3.5mm but I will be using 6 of these (per side) in an array. I haven’t modeled these yet but I think they will work out well.

Finally, how does one figure the sensitivity for mids/woofers used in a dipole? The 8 ohm Audax’s are rated at 87.3 dB (2.83V/1m). They will be crossed over to a 4 ohm driver rated at 88 db (1w/1meter).

Thanks,
Aaron