AUX IN issue

[chiphead]

DM10. Use only headphones.  I purchased a 1/8 inch to dual RCA jacks cable. If I plug the RCA jacks into AUX IN and the 1/8 inch end into my laptop I can hear music from the laptop through my headphones. I cannot hear my drums. If I unplug one of the RCA jacks from AUX IN, I can hear music on one headphone and drums from the other. And it sounds like crap. Is there a way to get both AUX IN music and drums to play through both channels of my headphones? Thank you.

[Chaser]

DM10. Use only headphones.  I purchased a 1/8 inch to dual RCA jacks cable. If I plug the RCA jacks into AUX IN and the 1/8 inch end into my laptop I can hear music from the laptop through my headphones. I cannot hear my drums. If I unplug one of the RCA jacks from AUX IN, I can hear music on one headphone and drums from the other. And it sounds like crap. Is there a way to get both AUX IN music and drums to play through both channels of my headphones? Thank you.

The original DM10 I presume (only one with RCA jacks)
I still have one for trouble shooting etc..I just tested with a Tablet..phone and Audio Interface to the RCA jacks and had no problem..other than I forgot to turn down the audio at the source as there is no Aux Volume control for this module and blew my ears out..

It shouldn't be shorting a channel like that..even if I disconnect one RCA the headphones remain stereo and I hear the drums in stereo...Laptops are notorious for bad sound cards but generally that's for recording not playback..and usually users download/Install ASIO4ALL

To double check.. it's a stereo TRS 1/8" to (2) mono TS RCA...The sound card on the laptop..is there more than one output option?...does it have a line output and headphone output?..If you are using the headphone port is it a "combo" port for a mic?..usually those ports have trouble with the rings lining up properly especially with Apple products and there is voltage sent on one ring to power the mic..

[chiphead]

Chaser, well...I'm an idiot. Yesterday when I first hooked everything up, I too "blew my ears out". So I immediately started going through the module looking for any thing that would adjust input volume and also let me hear my drums. Duh. I connected both my phone and laptop today and after adjusting output volume on either device, I can hear the music AND my drums. Thanks so much for pointing me in the right direction.

[Chaser]

Chaser, well...I'm an idiot. Yesterday when I first hooked everything up, I too "blew my ears out". So I immediately started going through the module looking for any thing that would adjust input volume and also let me hear my drums. Duh. I connected both my phone and laptop today and after adjusting output volume on either device, I can hear the music AND my drums. Thanks so much for pointing me in the right direction.

Happy to hear it wasn't a hardware issue as that can be a pain to troubleshoot..
Nobody is an idiot..lol....except maybe the designer/engineer who didn't consider the Aux volume/level
Common sense would dictate that if a module has an Aux Audio input feature , there would be either a physical knob/slider on the module or at the very least something in the firmware..even if it's just volume only...

The STRIKE , DM10 MKII Pro modules and the STRIKE Multipad  have physical Volume knobs for the Aux input..

EDIT:
There are a number of options for a 1/8" inline volume controllers available
Examples Amazon