What exactly is in "Amp Match?"



  • Hey Guys, long backstory, but to make it short and sweet, does anyone know exactly what Amp Match does? I mean, I know that it is used to create a software sim of a real life amp, but what is it in actuality? Is it like an extra equalization that happens at the end of an amp component chain, or does it encompass an additional cab/IR after the amp component chain?

    Ultimately, I'm trying to figure out what is going on inside of that magic black box. I'm just trying to increase my knowledge of how to build custom amps in Bias Amp, and I'd love to know how to modify components/add eq/etc to do the same thing that is happening in amp match.

    Does that make sense?


  • A2

    I think its just EQ, I don't think it has a dynamic component at all



  • @pipelineaudio Thanks! So if that's true, then it should be possible to place the amp into an FX chain in Bias FX, place an equalizer at the output of the amp, turn off the amp match, and then vary the EQ to get the same tone as the amp with amp match turned on.



  • @kenny said in What exactly is in "Amp Match?":

    @pipelineaudio Thanks! So if that's true, then it should be possible to place the amp into an FX chain in Bias FX, place an equalizer at the output of the amp, turn off the amp match, and then vary the EQ to get the same tone as the amp with amp match turned on.

    No, not really. Pipeline is correct that it is not dynamic and is a virtual EQ but you shouldn't conclude it is a simple EQ. In fact its a super complex EQ curve depending on the deltas between the source and target.

    The amp match automated EQ functionality is more like an IR (which in practice, for guitar cabs is also a complex EQ) in that it is an extremely fine grained frequency spectrum match. You would need a fully parametric eq with thousands of bands to fully replicate what the frequency matching that the amp match does for you automatically.

    A lot of what you perceive as differences between different sound sources boils down to their frequency spectrum. If you do a good job picking the amp type, gain levels, and input EQ of the starting point (i.e. start from a relatively close place) the amp match can be pretty awesome. If the source is bad or the starting point bad, it can vary from unimpressive to off-puttingly bad. I think this has given a lot of people a bad idea about it...

    Fun fact: people were manually doing amp matches by essentially shooting IRs before automated tools like the Bias Amp and the Axe Fx automated the process (not mention the Kemper; which is different in that it matches the frequency and dynamics of the operating point being profiled). The Axe Fx can export a tone match block to an IR still, IIRC.



  • @elric said in What exactly is in "Amp Match?":

    @kenny said in What exactly is in "Amp Match?":

    @pipelineaudio Thanks! So if that's true, then it should be possible to place the amp into an FX chain in Bias FX, place an equalizer at the output of the amp, turn off the amp match, and then vary the EQ to get the same tone as the amp with amp match turned on.

    No, not really. Pipeline is correct that it is not dynamic and is a virtual EQ but you shouldn't conclude it is a simple EQ. In fact its a super complex EQ curve depending on the deltas between the source and target.

    The amp match automated EQ functionality is more like an IR (which in practice, for guitar cabs is also a complex EQ) in that it is an extremely fine grained frequency spectrum match. You would need a fully parametric eq with thousands of bands to fully replicate what the frequency matching that the amp match does for you automatically.

    A lot of what you perceive as differences between different sound sources boils down to their frequency spectrum. If you do a good job picking the amp type, gain levels, and input EQ of the starting point (i.e. start from a relatively close place) the amp match can be pretty awesome. If the source is bad or the starting point bad, it can vary from unimpressive to off-puttingly bad. I think this has given a lot of people a bad idea about it...

    Fun fact: people were manually doing amp matches by essentially shooting IRs before automated tools like the Bias Amp and the Axe Fx automated the process (not mention the Kemper; which is different in that it matches the frequency and dynamics of the operating point being profiled). The Axe Fx can export a tone match block to an IR still, IIRC.

    Thanks Elric. Kind of disappointing, but not unexpected. I find it amazing how I can turn on the amp match, and suddenly an amp that sounds flat and dull becomes Dimebag's Krank. And don't get me wrong, I love amp match, and I'm not looking for a way around it. I'm simply trying to get better at building amps from scratch in Bias Amp 2. It's just that it now seems like the only really hot amps come from amp match instead of the other components.



  • @kenny said in What exactly is in "Amp Match?":

    Thanks Elric. Kind of disappointing, but not unexpected. I find it amazing how I can turn on the amp match, and suddenly an amp that sounds flat and dull becomes Dimebag's Krank. And don't get me wrong, I love amp match, and I'm not looking for a way around it. I'm simply trying to get better at building amps from scratch in Bias Amp 2. It's just that it now seems like the only really hot amps come from amp match instead of the other components.

    As with most technology the magic goes away when you understand how it works. ;) With regard to 'regular' mods: Actually this is the Bias 1 info but it still applies for the most part:

    https://help.positivegrid.com/hc/en-us/sections/200558975-Product-Information

    That link describes the various things you can tweak on the amp in Bias and gives some description of what you are changing. It is a pretty nice reference. Would love to see PG revamp the docs after the initial rush of work for FX 2.

    I tend to work mostly in FX but I have pretty much split my Bias time with matches and the other parts of the program.


  • A2

    I did a few videos a ways back that can show how to turn an EQ into an IR and vice versa, but like Elric said, when I said "just EQ" that is kind of not saying just how profound that is. It can be something that would take you a four hundred band EQ to pull off. The impuse response can be disturbingly complex