How to duplicate guitar sounds?

I can make or find an acceptable sound for original songs but I sometimes hear someone else's guitar sound I want to duplicate it.

I soon found it's not at all easy, I have no idea where to start.

I have Guitar Rig but I don't know which one of the 600 amps was used, never mind all the other crap you can load up.

This seems like something you can only learn by fiddling for 40 days and 40 nights..?

Maybe not, does anyone have any tips?

I'm particularly interested in nu metal sounds, very heavy but without the tinny shredding on the top end, probably dropped tuning and sometimes I think I detect a tad of wah in there somewhere.

I can post and example if someone can suggest where/how.

Thanks - rev

I have been lucky enough to make a living as a musician,producer for over 40 years. As such I can tell you as a guitar player,for some certain styles of music there are certain given instruments. Most country sessions are Tele and a Fender or Fender type amp. Blues is everything from Les Pauls,335,Strats,Teles. Depending on the artist you try to copy in Blues,it could be Marshalls or Fenders. Classic Jazz is a Hollow-Body Electric. Gibson 175,L5,Super 400. Usually through a very clean Fender,Polytone,or even solid state amp. Rock tunes could be anything at your disposal. Take into consideration also the huge guitar track you are listening to could be several tracks mixed together of different guitars and different amps mixed to sound like one track. I have been asked in metal situations to multi up to six tracks of rhythm with six different combinations of guitars and amps! This is just to start. Beyond that, add in what effect we use. What mic is on the amp. And placement. While I love the amp sims, they will never come close to real sound of a miced amp in a really good room. I hope this was a good starting point for you. 

Glad to help. Also, be aware that if you are stacking tracks to not use any chorusing or doubling because you are creating that effect by stacking. Those effects are,imo,to re-create live what you can't create without actually having those players or tracks on stage. Panning is also critical. My fave is a wide spread, 2-3 tracks hard left,2-3 tracks hard right. And try to keep away from having thin sounding tracks on one side while one side sounds huge. Try to mix a nice sound of similarity although it is panned hard left and right. This also leaves that nice big center channel hole for your solos to really get up front. BEWARE! NEVER cover up your rhythm section. There are so many tracks of guitar, you can tend to lose the focus of the Drums and Bass. Try to keep those drum tracks clean and slamming. Just passing on some experience. I hope it's of help to you.

1)  As I recall (nu-metal isn't exactly my scene), the original "template" was Ibanez 7-strings and Mesa-Boogie Dual Rectifier stacks.  I would guess that any simulator package would have a model for that.  Other amps you see those guys playing include Bogner Uberschalls, Diezels, and the big Peaveys (5150s and later).  If your sim has models of those, one of them might have the sounds you're looking for.  Maybe try a Soldano or modern Marshall model for lead parts.

2)  A lot of times, a model that sounds good by itself will have too much bass, distortion, and/or verb once it is in a mix.  Even a downtuned, heavy, chunking riff doesn't need so much low-end that it muddies up the bass guitar part.  And a rhythm part that sounds huge and menacing by itself might just sound like mud or noise in a mix if it's slathered in verb and distortion.  If you're having trouble getting the part to sit, try backing off some of that stuff.  Using panning (per Sidroe's comment above) and maybe some highpass or shelving eq to tighten up the low-end of a guitar part can leave the necessary space for the rhythm section in the middle of the image (and the bottom of the frequency spectrum).

Isn't it "heavy handed" advice that actually the OP should have a dozen different guitars, amps, cabins an mics? Worth 100 000 dollars or so. Tough :o)

Of course, if you want to dupliucate a sound it's best if you have the same gear.

If the OP has one guitar, one amp, one cabin and maybe a few mics, and some FX, amp sim VSTs etc his only option is to learn to know his gear inside out to be able to duplicate what he hears. Of course knowing what is used by the "target artist".

If he's got resources for buying a guitar here, an amp there, then  it's another thing.

Speaking from experience, it has taken me years to collect the battery of guitars and amps I have at my disposal. A lot has been said about amp sims or the "real sound". I can tell you from working with some of the big name artists, a lot is to be said about the actual sound coming from the hands of the player. I can take you and put you on any guitar player hero's rig, and you will never sound exactly like him at all. There is something about the fingers pressure on the fretboard, the pressure exerted on the pick, the note choice at any given time, etc.,etc. I always thought it was great to want to emulate someone else's sounds, but still try to maintain something of your own. I had the pleasure of spending a good deal of my life on the road with some pretty heavy hitters at the time. Later, while doing the club scene we would perform some songs of groups we had toured with. I always thought it was a better compliment when someone said they liked the way we did that song rather than "You sounded just like the record!" I say this to encourage you to always pursue YOUR sound. I agree that you need to know your gear inside out. Know every possible color on your palette. If there is a particular guitar or amp combo you are wanting for, see if you can rent or borrow from a friend before you invest any money. I wish you well!