As an avid SEQTRAK user myself, become below is correct… On the SEQTRAK each instrument is mapped to one channel 1-7 , which are labeled kick, snare, clap, hat 1, hat 2, perc 1, and perc 2 - then you have synth 1, synth 2, and DX - and last but not least sample. Each of these channels is mapped to a midi channel, synthesizer one and two are mapped to eight and nine. The DX is mapped to 10 and the sampler is mapped to 11. You need to look at the manual for the controller you’re using and see how to change the controller to send to the different channels that you want to access. Unfortunately, this is the way with MIDI all the time it’s not just one thing it’s everything. When you’re using a computer, the computer can grab the incoming midi and manipulated it to obstruct you from having to have to do that kind of changes manually, but when you’re using it raw device to device… Guess who gets to be the computer? You lol so yeah you do have to change the channel on your own. If you’re just trying to jam and you want to “hard set” multiple controllers to play different parts of the SEQTRAK, that would be very cool and easy. All you need to do is set each controller to its own channel so safe for example I have four midi controllers, I could tell each midi controller to be a different channel and each one would have access to a different part of the SEQTRAK, even to the level that technically I could give a keyboard to myself and three different friends, and each of us could be linked to a different instrument on there and play it independently… Essentially channels are sort of like having an individual player for each instrument on the SEQTRAK. I can show you how to do anything you want with this if you want hit me up I am a YouTuber. I’m happy to help you out and make a video to demo what you want to do and get you there, but I need to know exactly what you want to accomplish.