My 68 Princeton and my CLR can be setup to sound near identical, in my room, at a given volume level. I'll use a A/B box and toggle between them and honestly can't tell which is which, provided I did a couple of things; adjust the overall EQ, high and low cut in the cab block etc to achieve a similar tonal response. Adjust the output levels using a SPL meter to make sure they have equal output, and most importantly, either tilt my Princeton back so its facing my ears, OR, put my CLR on its side, into a 'backline' position instead of a wedge, so its speaker is facing my legs, same as the Princeton when its flat on the ground.
Do all that and I can close my eyes and play them side by side, and at about 8 feet away, I can't tell which one its coming from they sound so close. Both sound exactly "in the room" as I'm used to hearing them in my room. Now if I changed the levels, cranked the Princeton to 6 or something, and dialed in the Axe tone to match the breakup, I no doubt would hear a difference. The way that 10" open back speaker behaves at different intensity levels isn't linear. The position of the amp to a rear wall will make a huge difference too.
A loud open back combo, with a rear wall behind it it going to throw sound around the room very differently than a wide front dispersion FRFR speaker, just like a 1x12 closed back vs open back will. That is just simply acoustics, nothing to do with real amps vs modelers.
Ever play an open back combo on an outdoor stage ? Heck, just take out outside onto your patio.... Without the nearby walls and ceiling to bounce off the sound is sure a lot less full and rich. You've still got a real amp, you've still got a real guitar cabinet, but suddenly its not the "amp in room" sound your used to.
Ever play your amp in an unfinished basement or garage ? Sounds awful in that highly reverent acoustic space doesn't it ?? Its still a real amp, and a real cabinet, in a real acoustic space, but you don't see people waxing nostalgic about that "amp in room" sound do you ?
People want the sound of an amp in a good sounding room. You want the less directional low freq to bounce around, with you want the boundary effect of the walls and ceiling right angles to enhance the bass response, making a 1x10 sound huge. You want the directional highs not facing your ears, and the carpet, rug, drapes etc to damped the frequency response, giving this really full and rich tone without too much highs. It sounds really good, it does. But, it can also sound really bad. Point your amp at your ears, in your basement... yuck.... ice pick city and yet really muddy... awful tone but its the prized "amp in room"
