I have mid drive Twist Throttle Raleigh eMTB and the hub drive Thumb Throttle Ebike in my Avatar.
They both work the same Little twist/Little push go slow. Big Twist/Full Push go fast and slow/faster speed in between.
That JBL speaker is cool but too expensive to ship to Ontario CA.
I bought this speaker at closeout electronics store and it's good.
I rigged up a handle bar mount to the speaker with spare bike light bar mount clamps.
This is the bike you are riding correct?
It is not designed for pedaling distance.
Does your bike travel 28 miles with throttle and pedaling on a charge?
cause if it does, throttle more, pedal less, you'll make it.