Bad sound quality for lr-atari800

[mahcneto]

Pi Model or other hardware: Pi3 B+
Power Supply used: official Pi3 power AC adapter
RetroPie Version Used (eg 3.6, 3.8.1, 4.1 - do not write latest): 4.5.1
Built From: Pre made SD Image on RetroPie website
USB Devices connected: Keyboard,
Controller used: 8bitdo SNES pro pad
Error messages received: none
Guide used: https://github.com/retropie/retropie-setup/wiki/Atari-800-and-5200
Emulator: lr-atari800

Everything else is OK, pad & keyboard support, it is just about the sound quality, I don't know what's happening but I used to have an older retropie version in a previous SD card and for the sake of being up to date I bought a new one and started from the scratch. Previous retropie atari800 didn't supported pad with some keyboard mappings on it very well, this new one does but it's just the sound quality being this bad, it's like it's missing a channel or something. Tested Oils Well (great game) and the in game music is missing, also tried Ninja, same thing. BIOs are ok and working, I'm using the same I had in my previous one. Any clues?

[mahcneto]

Ok I just did one more test and I downloaded the Atari800 core from the retropie setup and it does have perfect sound quality (audio coming from my left speaker only, though), and it uses the same BIOs files than the lr-atari800 core. Is this normal? I want to use the lr-atari800 because of the keyboard being mapped to the joypad, or maybe if it is a way to get into the Retroarch menu in Atari800, and the set up my gamepad being Atari Joystick?

Thanks in advance!