You can try Voodoohda 2.8.4 for your audio, which (if you have more than just two speakers, like my HP Envy does) will improve the overall sound, however if you only have two speakers the patched AppleHDA will be fine, I believe to use it you need to create or edit your dsdt and find the part about audio, your layout ID may be different than mine, but for me it had to be set to 12. Since you used Iatkos (ugh, I hate distro's, they're too easy/and there's no way to know why something does or doesn't work) you are probably using chameleon as your bootloader right? Try voodoo hda 2.8.4 first and see if it works.
Before using Voodoohda you have to remover AppleHDA or you will probably have a kernel panic/reboot. Don't forget to move AppleHDA first if you do go this route