Firstly, it's important to confirm which audio ports are featured on your sample pad and drum module. Most sample pads have 1/4" line-level outputs, and all Alesis drum modules have a 1/8" aux input.
You'll need to use a Y-split 1/4" > 1/8" TRS cable to connect L & R 1/4" outputs to a 1/8" aux input. Please refer to the diagram below.
Your speakers or headphones should be connected directly to the electronic drum module, not the sample pad.
The aux port on all Alesis modules are routed directly to the main and headphone outputs, so you will hear sound as soon as you begin hitting the pads of your sample pad.
To balance the sound, please utilize the main outputs on both devices.
The main volume knob on the drum module will adjust the overall volume for both devices. However, the onboard volume control on the sample pad affects only its own volume.
To explore your options for adjusting the volume level of each individual pad, please refer to the documentation that was included in the box with your product.
If you have any questions, please submit a support ticket: Submit a ticket : Alesis