Well, we also understand, that if his main rig goes down, or he needs to use his practice rig, or doesn't bring his modded Speakon cables, or lets a fellow guitard borrow his cab, he can't make his cabinet Speakon-only. Also, we didn't really want to have two Speakons and two 1/4" jacks.

So we used the Speakon Combo jack. The center of the jack has the 1/4" fitting included in the Speakon jack! Hella-awesome design. Great idea. BUT... these contact tabs on the back side of the jack are designed for soldering the jack straight to a circuit board. NOT for clipping on a speaker wire lead, or even to solder a wire to the tab. Made it very very difficult to install.
Well... they now make it easier to install them!

The new horizontal-mount Speakon Combo jacks now have their rear contacts angled downwards, to mount your jack at a right-angle to a circuit board. Because of this layout, the tabs that get soldered to a circuit board are far longer, and give you much more contact surface for a wire clip to fit on. You can kindasorta bend them out a little, and use the nice large wire clips for a tight snug connection. (Yes, I've emailed and bitched to them, that they should make a version that allows wire-soldering to the contacts instead of PCB mounting, I'm glad enough that they even made this version!)
Here's the website details, with the technical drawing in PDF format.
http://www.neutrik.com/us/en/audio/210_ ... etail.aspx
So what are the benefits, you may ask? Easy. Interchanging cable styles, yet keeping the jack plate small and simple. If you do a gig and a Speakon cable, saaaay, gets cut in half in the tailgate cuz your buddy slams it shut without checking, and you don't have a spare Speakon cable, you're screwed. But... damn near everyone everywhere has a spare 1/4" speaker cable! What if you're setting up in a small club and don't want to bring 40 pounds worth of 50-foot Speakon cables, and just wanna use your short 10-foot 1/4" speaker cables? You're good to go. What if you lend your cabs to someone, who doesn't have any Speakon cables? His old cables are still compatible.
This Speakon Combo jack allows you to upgrade your safety and performance, yet retain backwards compatibility. And you can do it, all with only two jacks. No need for four ins n outs. So say you use these jack cups:

These dishes don't have room for extra 1/4" jacks. You'd have to drill holes on the bottom slope, which defeats the water-hazard purpose of these dishes. But putting the Speakon-Combo jacks in there, you're good to go.