Yamaha DTXpress/DTXplorer/DTXtreme

Greetings to all...

Thought I'd put this on the table for some intelligent answers..

Currently, on the DTXpress11,  I am employing one TP65S pad for my 
main snare. I wanted to add another pad (TP65) as a second snare on 
my right side for more flexibility. I used a "Y" stereo splitter from 
the DTXPRESS11 module
(input2), and extended TWO STEREO cables from the two stereo ends of 
the "Y" splitter to connect to the TP65S and TP65. I noticed after 
making the connections that the VOLUME of the snare seems to decrease 
a bit for BOTH the TP65S and the TP65, during normal operation. With 
the snare volume cranked up between 90-100, it still seems too low.

Questions:

1. Is there a problem with the way I have connected the two pads 
using the method above??
2. Should I use a MONO Y splitter and 2 x MONO cables to each of the  
pads?? or...
3. Stereo Y splitter with 2 x mono cables to the TP65S and TP65??

I still want to retain the 3 zone capability on the TP65S, and normal 
pad operation on the TP65. 

What is causing the volume of the pads to decrease??

Any input would be appreciated..

Best Regards.