I plan on purchasing a Yamaha DGX 670 soon, and with all the previous generations, the DGX series lack speaker output quality, only about 6W each, but yet has a great touch, full 88 keyboard, while offering a large selection of rhythms. The Audio Technica headset makes the DGX sound like a concert grand. Yet when I plug the DGX into the Yamaha Stagepas 400S portable PA system, it's been very disappointing. Despite making adjustments with the controls, the midrange output is distorted and cheap sounding. Has anyone had experience with the Bose L1 Pro8 Line Array system? I've heard several of the Bose L1 Pro systems at larger venues and the sound is amazingly crisp and powerful. The L1 Pro8 would be perfect for my size venue, but it's also a $1200 item, so can I make the DGX better sounding with the Bose?