The MG-400 includes multiple impulse response of 512 samples each. You can load 3rd party IR files using our NUX QuickTone edit software (support up to 48kHz sample rate). The included 25 guitar cabinet IRs combine 4 classic microphones with 3 mic positions to allow beginners a quick and easy way to jump into the multi effects experience. Also included are 8 bass cabinet IRs and 3 acoustic guitar IRs, giving you the ability to play bass guitar on MG-400 or use electric guitar to simulate acoustic guitar sound with acoustic guitar IRs.