pair of 410s...stacked or side by side?

Aesthetics.

Stacking makes more sense to me for the audible reasons and to have the head/knobs at eye level. Do whatever your comfortable with and what your ears tell you sounds better. From my experience, it's better to take up less realestate on stage and to have a smaller footprint thus stacking upwards instead of outwards

 

Vertical stacking is always better than horizontal.

 

+100!!!!!

 

It's not just aesthetics, it's audio science.

Vertical always, never side by side.

 

You get better horizontal dispersion through vertical stacking as I understand, due to interference and wave cancellation. Which means that stacked vertically, you are broadcasting to the room instead of bouncing your sound off the ceiling or projecting into space.

Has to do with the line array principle: http://en.wikipedia.org/wiki/Line_array

 

Exactly. The sound is closer to your ears which results in you turning your gear down because you can hear yourself better than having the speakers on the ground

Plus, you take up the same amount of space on stage as one 410.

 

Stacked.

 

And some times we Country,
And some other times we Blues!

 

Stacking them on a tight stage makes sense but placing them on either side of the stage would help with coverage and monitoring.

You could run across the stage and still hear yourself and guitar dude on the other side would be able to hear you enough to keep in time. Just sayin' =)

 

This is erroneous. Stacking increases your dispersion aka coverage.

 

In that case you loose most of your hard earned midrange intelligibility
and effectively half your amplifier power.

 

Even worse then side by side

 

Question:
Why have I seen many guys on TV shows laying their Ampeg 810 on it's side?

 

Because they don't know, or don't care.

 

Because they aren't connected to a head?

If your a 99%er player, yeah vertical and all that. But if you're a big touring guy with all FOH sound and just paid to show off the amp maker's badge, doesn't matter. Oh wait, it's easier to see the brand stacked vertically, too.

For the record, John Stirratt sounds great live dispite his side by side 4x10's. (see above)

 

Also because it "looks cool". They could also be fake cabs and/or the bass player is already getting everything through in-ear monitoring. Maybe the bass player likes to hear less midrange on stage. In some bands (midrange heavy guitars) this can be really helpful.

 

I've seen Richard Bona live a few times and he seems to like 410s side by side or even spaced apart a bit. Same with Paul Turner with Jamiroquai. But I've seen way more upright 810s.

 

Best 410 is two 210 stacked vertically and everyone else halve their output so the front 25m of audience don't go home with an increment of permanent hearing loss, nevermind the band. The other 410 is listed for sale.