Understanding IRs, matching, Celestion,...

  • Hi,
    I have a big big mess in my head, I just do not understand the operation of the IR, the matched amps, etc.
    The preset that I use most now is the Matched AC30 handwired GY, downloaded at the positive grid cloud, and if I look at it in Bias it is configured with American elements instead of British and Blackface speakers instead of greenbacks or alnico blue ones.
    How do these Matched amplifiers work? If I modify the configuration with speakers from the Celestion pack for example, can it be improved?