The CSP-170 is noticeably upgraded with bigger, fuller sound and I personally like the wood white key action of the CSP-170 better than the plastic key action of the CSP-150. This produces a fuller, more resonate sound with improved bass reproduction.

In their own acoustic chamber speaker box mounted just underneath the piano.

The CSP-170 has substantially increased internal audio offering 180 watts of power going into 4 speakers and amplifiers with the main speakers housed The CSP-150 piano model has the GH3X plastic key action and also and internal 60 watt 2-speaker sound system whereas the the CSP-170 (below left pic) has a wooden key (white keys only are wood) key action. But before I talk about this very powerful Yamaha app, I want to talk about the key action in this model.

This is where all the real excitement and power resides and how these relatively 'simple' pianos become monsters:). But what really makes these pianos incredibly amazing (in my opinion) is their proprietary Yamaha iOS app for iPad/iPhone called Smart Pianist.

Ipad csp