Re: by yourself vs in the mix
I don't really know what to say in regard to amp combos or such, but as far as being in the mix per se' ... well I have noticed(quite often ) that even though a scooped mid tone often sounds good post distortion for some metal, and even hard rock (less mid scoop) theat any lead work tend to get lost immediately, or it gets jacked up so loud that it sounds really thin and *empty*, and chord work tends to have very little definition, and a loss of chunkiness and crunch. The dynamics simply don't come thru as well.
Often times what works well in solo practice just doesn't fly with other instruments ... the catch is for each instrument to have it's own frequency range, that way when mixed together they don't compete for the same musical space. Like frequency components playing in various phases tend to cancell each other out ... some people have experinced this problem when doing three (or so) overdubs of the same rhythm part, with the same tone. They expect to hear this *huge* tone, but what they get lacks punch,is muddy, and well not really able to hear the separate parts. Now when they take the same thing, and vary the tone on each track, much better separation, and definition, not to mention dynamics.
The problem though seems to be more of a problem with he core tone (although I bet he won't think so) ... here's a trick,if you can record on an MTR or multitrack on a computer, or even record the band rehearsal/jams thru a mixer but mix his guitar one one channel and mix everyone else to another channel. Then play it back with the two channels apart, then mix them to mono with the pan controls and let him hear the difference between how he sounds separate and how he sounds blended with the band.A step further would be to run his channel into an eq and return it back into the mixer; then you can eq his guitar so that it sounds good in the mix (or let him do it),then pan the channels out again so that the band is again on one channel (left maybe) and he is on the other (right) ... He'll hear how his tone know sounds different, and he might not like it the way it sounds by itself ... but he'll hear the difference when mixed together with everything else. Call it an object lesson. Just like in most recording you want a very tight and not overly low endy signal, with a lot of the natural mids. Funny thing how you can always add highs and low end, but if it's too much low end to start with, you can't take it back out,if it's too screechy ... you're stuck with it, you can suck mids out, but putting them back in doesn't work as well (IMHO) ... just my take on it.Maybe someone can give you an answer on the gear thing.