If you have the right amp simulation for your needs, but can’t find the right cabinet… then make your own using an EQ! For example, I like the Metal Lead amp in AmpliTube 4, but on a recent mix I found the matching cab didn’t give the sound I wanted. Although some of the other cabs came close, I had very good luck building a custom amp sim cabinet from multi-stage equalizers. You’ll need an EQ that includes high- and lowpass filters with sharp cutoffs (preferably 36 or 48 dB/octave), a high-frequency shelf EQ, and some parametric stages.
The screen shot above shows the cabinet I built for the Metal Lead, which is representative of the kind of EQ changes you want to add to an overdriven amp. The main modifications are a high-frequency roll-off to shave off the top end and amp sim harmonics, a midrange cut around 1.3 kHz to reduce the upper mids as well as make the 200-500 Hz range more prominent, and a steep, deep notch to minimize a buzzy resonance at 2.9 kHz. A mild bass roll-off with the highpass filter can provide more of an open-back response, while adding a high frequency boost with a shelving EQ regains the perceived loss of highs from the notch-removing resonance. Sometimes adding a slight upper bass/lower mid boost can give a beefier, more powerful feel.
After Fuzz or Distortion
Another advantage of creating your own cabinet by using filtering is that you won’t have the “digital” sound that impulse responses sometimes have. Furthermore, you might find that adding this type of pseudo-cabinet after a fuzz or distortion will give a desirable sound that’s more appropriate than using a standard amp/cabinet combination.
Note: the question here isn’t whether the constructed cabinet is “better” or “worse,” but whether it fits well to a particular song. In my case, it definitely was—but the real point is that you can create something that’s ideal for your needs, rather than using something that was ideal for someone else’s needs. Have fun experimenting!