The E80 is already weighs 50lbs. And you want BETTER (read 'heavier') speakers in it? LOL.....
T2 already figured it out: no-one wants to carry the weight. It takes a system with a sub to make any decent volume out of the hi-fi sounds in a TOTL arranger. Who on earth wants to run a $4000 arranger through tiny 4 inch speakers?
Save yourself 5 pounds, get a G70 and get a decent 76 note keyboard thrown in for free.... Then at least get a 2.1 speaker system that can stay clean at the volume levels you REALLY want to play at!
I know, I know....... somebody is going to chime in and say how wonderful the speakers are in THEIR arranger (PSR, anyone?). To which I say, if they were THAT good, why didn't Yamaha use them in the T2?
Perhaps they realized that after paying that sort of money, firstly, most are going to want to hear it through better speakers, and secondly, that customer COULD afford a decent system, or already had one!
Unfortunately, Roland have yet to understand that their target audience can't lift 50+ pounds!
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An arranger is just a tool. What matters is what you build with it..!