It's difficult to know what exactly you're trying to achieve. There are so many tones.
I think you have to play a bit with the different settings to becaome more familar with the tones you can get. And I guess the sound of a rig played on a cab will not be the same when listened with earphones : your earphones may have a baked in eq for example (they often have boosted lows).
What I would do is a patch with an amp sim of your choice and then the AcBsPre.
Set the AcBsPre with a gain of 50, Depth at 10, Level at 100 and everything else at 0. Like that it will be flat and have a unity level.
Then check that when you press "Total" balance and level are at 100 on your patch.
You can now play with the amp sim :
- tweak the knob to feel what frequencies they impact as they're different depending on the models, and play with the cab sim level + model.
I have the feeling, but I may be wrong, that when the cab sim are set at 100, they're too heavy : heavy cuts in the mids.
You can try with a level between 30 and 70 if you want to feel the cab sim effect with a less important impact. Or set at 0 if you don't want to have it at all.
- what I saw too is that most of the amp models are almost flat when Bass, Mids and Trebles are at 0 (Bassman and SuperBass are different : they have a strong baked in voice). It's different from the real models who often have a strong baked in tone (bigger low mids and trebles for the ampeg, big lows and highs for the GK,...). So to get the feeling of the flat setted amp you already know you'll have to play with the knob.
- Once you have the feeling you're in the good spirit but still not there, you can use the AcBsPre to push or cut some frequencies :
- Bass is set at 40 hz
- Low mids are set like you want
- Mids at 1.6 kHz
- High Mids at 3 kHz
- Highs : way higher (I don't remember the exact value)
- Depth is a HPF : it cuts the ultra lows (10 = full lows - 0 = full cut)
- Reducing Highs can help to simulate the High end roll off of a cab without tweeter.
So, a lot of informations and possibilities
The nice thing on the amp sim and AcBsPre is the sweeping mids. You can push or cut the mids you want and it will have a big impact on your tone.
If you're not sure where to go, set the mids at 7 for example and sweep them. You'll hear clearly what nuance it can add to your tone.
Then do the same at -7.
It's really a matter of time to get used to all this settings. They help you to get as many possibilities as you want, but it's less simple than a classic rig.