AR woofer query??

diyAudio Member
Joined 2007
The thread about the AR7 has made me realise that I don't actually know how to tell an acoustic suspension driver from any other type of closed box driver.
So what are the small signal parameters of an acoustic suspension woofer apart from an a low Fs.
As far as having a low Free air resonance I don't remember any 12" woofers lately that have one as low as 17 or 18 Hz, even my Kicker EX woofers are only 25Hz