Powered Speaker - Lo-Z Balanced Input?

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I have several Chinese clones of a JBL EON 15 G2 powered portable PA speakers made by "Naphon". (see pic attached). I don't have a schematic and Naphon can't provide me one. The input is 1/4" . I'd like to determine if the input will take a lo-z balanced TRS input. I can open up the amp and look but the presence of TRS connections may only be for "stereo" input purposes. Is there something I can measure with my DMM or look for that would help me determine if it is a lo-z balanced input?
Thanks.
 

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There are two input jacks; "Left and Main-Right". Only the right produces any speaker output no matter what the "Balance" control is set to. But very strange design. BTW - the main board is labelled "KS 153A". I googled it but couldn't find anything relevant. Each 1/4 female input jack is wired as mono although they are TRS ready. I opened it up and changed some connections around so that it seems to work fine feeding from the balanced mixer output. I decided to try to wire the "right" to Tip and "left" to Ring. That seemed to work although I have no idea whether I actually have a balanced line or simply unbalanced with an extra line. (Is there a way to measure with a DMM to see if it is balanced?) I'm speculating that a Chinese "engineer" may have been trying to copy the design from JBL or EV or etc. and mis-labelled what they found.
Anyway, I didn't see smoke or hear distortion so I'll modify the other units I have in the same manner. Thanks for your suggestions.
 
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