Powered Speaker and Subwoofer Connection NEED HELP

[acaoili]

I have a pair of JBL LSR305's and I use an XLR connection to a 3.5mm headphone jack to listen to music on them.

I recently bought a Dayton Sub-1500 Subwoofer to add more bass and I am having a hard time getting the subwoofer to work.

How I tried to connect the speakers to the sub: I split the XLR connection from the left and right speaker and converted the signals to RCA then connected both RCA's to the subwoofer. This doesn't work.

I stumbled across a weird phenomenon yesterday, I disconnected my JBL's power sources with the XLR cables still connected to the speakers and the sub and the sub started working.

Do any of you know a fix for this and how I can get both my speakers and the sub to work?

 

[americanaudiophile]

I would split the 3.5mm connection from the phone. Use one output directly to the subwoofer and the other as you had before to the JBLs.
The pin pattern for XLR is not universal so the adapters you used may not be correct for the JBLs.
When you turn off the JBL amps it may short two of the pins of the speaker input making the correct connection to the sub. That's just a guess though.