That's a great question! I hope you've enjoyed your Bose amplifiers so far!
In regard to your query, you won't be able to daisy chain the amplifiers together as you're describing. However, you can connect an older SoundTouch adapter to each amplifier and connect them to the SoundTouch app (but we no longer retail the older SoundTouch Adapter). Or, you could group your SA-3 and SA-4 using a SoundTouch Wireless Link as these two amplifiers have auxiliary inputs. This would allow you to connect both the SA-3 and SA-4 to the SoundTouch app to group the amplifiers and play audio across all connected passive speakers.
I hope this helps! Let me know if you have any queries regarding this.
Nov 12, 2015
thanks, what is the old soundtouch adapter called, which will work with an SA-2? Maybe I can find it on ebay.
It sounds like I can added the adapters to each amp (if i can find the right soundtouch adapters), and then use the soundtouch app for each adapter.
I see another response stating i can use a boselink A as well between two SA-4's, with a single soundtouch adapter. Does that only apply to SA-4?
Any news on newer protocol adapters coming out? I hear soundtouch is the older system. Not sure i should be investing much there. ..