Do cab IRs include the power amp, or just speakers / cab?

[musicalbox23]

This is going to be an embarrassing question but I'm not getting this;

If I take the speaker sim output from my SYN2, where does the "power amp" part of the tone come into play?

Does an IR (in the Syn or stand alone) contain the elements of a power amp? My understanding is that it's just modeling the cab & speakers. I which case, where's the power amp component?

Or, I could take the non-IR output and run that into something in my DAW that has both power amp and cab modeling (Helix Native, Guitar Rig 6, Torpedo Wall Of Sound)?

It just seem to me that "guitar > preamp > speaker cab > microphone > DAW" is missing an important part of the sound.

What am I not getting?

Many thanks!

 

[j4q0]

Short answer:
Taking the "raw" signal of any preamp (or OD pedal) and running into a power amp modeler and an IR loader will give the "same" result as using the IR out of the SYN2 and running straight into your DAW.

Long answer:
The SYN2 (and other gear) has a speaker simulator, which is a physical (analog) filter deigned to simulate the sound characteristics of a speaker, which is not the same as an IR.
An IR is basically a capture, a snapshot of a sound through a particular chain of pieces of gear.
In guitar world, that would mean a signal sent to whatever power amp was used to drive whatever speaker you wanted to capture, the speaker itself, the microphone, the microphone placement on the speaker (distance from the speaker, off vs on axis and everything in between, angled vs straight onto the speaker) and the interface used to digitize the signal.

Digital modeling of a power amp section would model the behaviour of the power when interacting with the changes of the speaker impedance curve and the voltage drop when playing.
I'm assuming the signal sent to the speaker when doing a capture would have all the nuances of these voltage drops and impedance curves so the power amp modeling software can model the correct behaviour of a particular power amp.


Disclaimer: I'm sure I'm missing some information in all of this and hopefully somebody that knows more than I do can explain it better. Regardless, this is a broad explanation of how an IR works.

 

[musicalbox23]

You, good sir, are a very adept edifier.

Of course whatever IR would have had to have been powered by a power amp of some sort! I don't know why I didn't put that together!

If anyone else has deeper / different insight, I'm al ears. But, thank you j4q0 for getting me sorted (and doing it quickly, without being condescending!).

Many thanks!

 

[buddachile]

The cabinet simulation output of the Syn2 does not have any power amp characteristics. Yes, the power amp component of the sound is missing.