There may be ways to add another BT receiver to your Studio 2. Such as something like the Miccus RX receiver that plugs into the audio aux in jacks.
As to delay, Bluetooth has an inherent delay so no delay is only possible when wired.
Okay so I purchased the HK Onyx studio a while back. Just picked up the second gen (HK Onyx Studio 2) Today. I also have the most recent Macbook air and a galaxy S5. I know I can't pair two speakers together without a stereo function on the speaker. Would there be any way for me to be able to pair both my senders ( Macbook + S5) together so each can send it's each individual signal to each speaker separately with no delay? I know this is a terribly convoluted question but it's the only way I could think of doing it.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic