[Jazzman53]

I just blew one of the Aurum Cantus MKII woofers in my 2-way TL speakers.  I could buy another AC MKII or buy different woofers.  Parts Express has a special on a different model Aurum Cantus 10" which has lower Q and and I'm wondering if that model would work better in my TL box.  I read different opinions on qts choices for TL's so I'm confused about which woofer would be best.  Here are the choices:

 http://www.parts-express.com/pe/showdetl.cfm?Partnumber=296-434
 http://www.parts-express.com/pe/showdetl.cfm?Partnumber=296-430

[face]

From what I read about AC, their published specs generally aren't close to their actual. 

[neobop]

I don't know about Aurum Cantus QC, but I think the Qts of the other woofer you're considering would be more appropriate for a TL. My knowledge on the subject dates back to the days of Speaker Builder magazine, but all recommended (for TLs) woofers had a Qts < .4

Judging from the review at PE, maybe you should find another brand of driver. Some guy bought 4 to use as subs, and blew them. With 150w rating on each and a Fs around 20Hz, you'd think they would be appropriate. Xmax is 8mm, so what's the problem, amp clipping?

It might be a challenge finding an appropriate replacement with 89dB efficiency and Fs around 23Hz for a 2-way. Maybe you should consider making it a 3-way. I assume your TL is tuned for 23Hz.

They used to say that appropriate woofers for TLs is knowledge handed down from one guy to the next. Can't really help you there but the Brits are really into them. Maybe you could get a couple of TDL woofers for your lines.
neo

[sreten]

http://www.quarter-wave.com/TLs/Alignment_Tables.pdf

Hi, if designed properly a different woofer will not work better, rgds, sreten.