Klipsch lascala subwoofer?

The cabinet design of the LaScala does not provide horn loading down into the subwoofer region; it is much too small to be effective at those wavelengths. Instead, the cabinet would act like a very small sealed box, of whatever internal volume is in the airspace behind the woofer cone.

If you insist on forging ahead, plan on using a great deal of EQ to get any kind of deep bass. So you'd want the subwoofer driver with the highest thermal power handling you can afford, making sure its magnet will fit into the available space, and plan to EQ the snot out of it.

But I don't think it's a good idea.

Duke
dealer/manufacturer

All you need is 1 good sub and it can be placed out of the way with a long interconnect. That is the best way if you want to augment the bottom end which it does not have. Remember bass notes are not directional. I hope I said that correct. I have 2 Dali Suite 1.2 subs 12" acoustic suspension types that I used with my Cornwalls. Well to be honest the Cornwalls didn't need the subs but one day I left them on and the Classical kettle drums shook the room. I enjoyed that extra bottom end. So especially when I listened to Classical I left the subs on.

There is another route you can go. It is definately a big enough box to convert into a subwoofer. After all, the internal volume of your speaker is bigger than most subs out there. You would remove everything that is inside it and turn it into an empty box. Give it some extra bracing inside, build a new motor board and install a 15" or even an 18" sub driver. Over at AVS, there is a DIY thread devoted to building speakers and subs. They can steer you to the right equipment and info needed to make a great sub out of your Lascala.