Deromax

Those kind of questions needs nothing more than the specs in the speaker's manual and elementary maths to answer.  This is a forum with a very specific subject, Crown amps, not a general purpose sound reinforcement forum.  This is why those kind of system design questions are received with lukewarm enthusiasm here.

Just so my post is actually somewhat useful, I'd say twice the continuous power of 240 watts for the pair of Bose (that would mean around 500 watts per channel onto 8 ohms) and 1000 watts per channel onto 4 ohms for the 2 pairs of JBL.

I had forgotten about this thread!

My K2 was repaired successfully and at a reasonable cost.  It's performing great now, powered since last december!   I love the new longer time constant too!

Thanks for the info.  I'll look it up.

Yes, no amount of scientific testing will change how one is happy with a component over another!  Trust your ears!

First, the difference between 650 watts and 1000 watts is less than 3 dB.  This is not "way louder", it's actually barely noticeable by ears.  What you are observing is the gain of the amps, which is higher on the X4000.  This is the input sensitivity switch we were discussing earier.  Set it to 1.4 volts and the volume should be more similar to the Xti.

Also note than when you want to compare components, you must adjust their gain so they put out the the same output, before listening.  That means playing a tone thru the system and setting the gain with a SPL meter to less than 1 dB difference.  This must be done because our brain will automatically prefere the louder of the two.  That's psycho-acoustic for you!  When you match the gain (volume) then you are really comparing the sound.

Since you are using the X4000 on 8 ohms mids, I think that a 15A service will be enough.  This is considered a light load on an amp!  

About the input sensitivity switch, the 0.775V setting should be used if the amp is fed by a DJ mixer, and the 1.4V setting is the standard if a pro mixer is used.