Ron...I have a Tyros4...I don't recommend using one Bose L1 with it...the T4's stereo (especially piano) doesn't collapse well to mono.

It's up to you, but I have tried two Bose L1's and they sound great, but they are very expensive.

I do clinics/demos for Yamaha Canada and they insist on me using a stereo system with the Tyros4.

If it was me, I'd go with a stereo system...two powered cabinets would be best...the Bose L1 is mono, and not suitable, in my opinion.

You've been warned. wink

Ian

PS...here's some info on Bose Forum:

http://bose.infopop.cc/eve/forums/a/tpc/f/8766055944/m/3056033565/p/1
_________________________
Yamaha Tyros4, Yamaha MS-60S Powered Monitors(2), Yamaha CS-01, Yamaha TQ-5, Yamaha PSR-S775.