Any way of recording internal audio on Android 5.1.1?

[SpicySalad]

I want to record games and whatnot for Youtube, but my current tablet is a cheap one with a garbage microphone, so internal audio recording is a must. I've been attempting this for ages with different screen recorder apps, but all the ones I've tried work ONLY through the mic. (I've even tried recording with my tab plugged into a good speaker system, but I have to turn it up unreasonably loud for my tab to pick it up enough to even bother.) A free/cheap method is preferable, but I'm open to any suggestions at this rate. Is there an app I haven't tried yet, an accessory, ANYTHING?
(Yes, I'm aware that there's a way of recording internal audio with the help of a pc and a capture card, but I can't get a capture card right now :/)

 

[Rukbat]

Go to the Google Play Store and search for Mobizen. There are a few versions. If the Youtube one isn't what you need, and your tablet isn't a Samsung or LG, just try them until you find one that works on your tablet.