treeincThe JBL LSR30X you are referring to are active speakers. They each have a power supply and amplifier built in to each speaker. This TEAC works for passive speakers that do not have their own power supply and amplifier.
treeincIt really depends. Passive speakers require an amplifier so that would be an extra piece of equipment required which can add to overall cost. This would make it easier to upgrade speakers/amps in the future should you so choose since they are separate pieces to the overall system. Active speakers, like the JBL LSR30X, already have a built in amplifier so it's an all encompassing package. Simply plug in your source and go. Here is a video by Zeos who explains it pretty well. Skip to the 3 minute mark.
https://www.youtube.com/watch?v=VVMqn8ptEz8