EXPRESS 5:50 Extension Cab Confusion - 2 Questions

[yardbird mac]

Assuming that I would want to run an open back extension cab with my EXPRESS 5:50, I'm a little confused about the dimensions listed for the EXPRESS 5:50 vs the listed extension cabinets. According to the info I've found, the dimensions of the amp itself are:
H = 19 1/2",
W = 22 7/8",
D = 11 3/4".

The "WIDEBODY" Open Back cab is listed as:
H = 16 1/2",
W = 22 1/2",
D = 11 1/4" (not deep enough by 1/2").

The "WIDEBODY" Closed Back cab dimensions are listed as:
H = 16 1/2",
W = 22 1/2,
D = 12 5/8" (deeper than the actual amp itself).

The "LONE STAR 23" Oen Back cabinet is listed as:
H = 16 1/2",
W = 22 7/8",
D = 11 3/4"


Question #1... I understand why the closed back cab is deeper, and the amp will rest on top of that cab nicely, but I assume I would want to run a matching Open Back cab with this amp (or not?). If that's the case... it appears that the LONESTAR 23 cab would actually be the better size match. Is the LONESTAR Open Back cab the one I'm looking for?

Question #2. If I run the internal speaker in the amp + an extension speaker, will it be safe to plug the ext. speaker into one of the 4? inputs?
Please help me here. I'm new to MESA Boogie and I'm NOT familiar with their speaker circuitry setup.
I'm recovering from a mild stroke (2008) and in my world 2 + 2 sometimes doesn't = 4.

 

[yardbird mac]

Anyone??? I would like to get the correct cab (or close approximation) sometime this week.

 

[Don]

I think that either widebody cab would be fine, though I would be inclined to use the internal speaker combined with a closed back extension cab just to mix things up a bit.

As far as which output jack to use with an extension cab, according to the manual, you should plug both the 8 ohm internal speaker and an 8 ohm extension cab into the 4 ohm output jacks. They also mention that most combinations of speakers and output jacks are acceptable.

 

[yardbird mac]

To ALL... many thanks!!!