Hi ST first of all I want to say thank you very much for your support every question I had in the past you just gave me the right way to go.
Just to remind you I am a mobile DJ and my setup is 2 sets of L1 M2 with 2 B2 i don't have a T1 so the output come from my controller DDJ-SZ Pioneer goes to my Yamaha MG12XU mixer and than goes to my speakers also I got a 2 JBL PRX 12 I use those to ceremony...I want to link JBL with my L1
I'm sorry that I didn't see your post in the middle of that other discussion. I've started a new discussion for you here.
I'm looking at the Owners Manual for the Yamaha MB12XU (you can download it from the Yamaha site). On page 24 you will see that you have several outputs.
I would use the 1/4" STEREO OUTs for the L1® Model IIs.
You should be able to connect from the MG12XU to the JBL PRX 12 using the
Group Out (blue),
Monitor Out (orange) or
Stereo Outs [XLR] (green)
Please see the Yamaha Owners manual for more information about those outputs.