Yeah when close micing there is often not a ton of bleed.
I have heard that Daniel Lanois would record Bono with a sm57 with the studio monitors blaring to make him feel like he is playing live. I have tried this and it works!!
That being said it can also be handy to dampen reverb to and I usually do.
You might want to look into something like this:
http://www.realtraps.com/p_pvb.htm
Hi Steve
From my experience treating the room made a huge difference to my vocal recordings. It was night and day. Of you are not going to treat your room try putting up heavy sleeping bags or duvets around yourself. Perhaps invest in a reflexion filter.
I would say treatment has even more benefit on recordings with a mic than it does with mixing after.
I’m with dave on this
About 10 years ago I went on a “crusade” to “improve” my sound, an I bought all kinds of higher end gear. when I got around to treating my room I noticed the biggest improvement of all.
Today my current room is untreated, but I do put up all kinds of blankets etc. when I record, which like you is mostly acoustic guitar, guitar amp, and vocals
Yeah, I’m no aucoustician like Paul W but I think the high reflections in an untreated room collect back at the mic and then, given that a lot of modern condensors have a freq “bump” in the high end I can easily see how a recording can end up seeming harsh
I concur with the above and also with the reality being that vocals don’t often sound best at 3" from the mic capsule (to keep the bad room sound down low). All of the things (re: problem solving) that some people take as “standard” studio methods kinda disappear when you have more space (a good space) to back away from the mic a little…
Sibilance, proximity effect, hard to control dynamic range… etc… become a non issue. And for sure, distance in a good room tends to “soften” vocals nicely. It’s the same reason why a snare drum often sounds much better in the overheard mics than the spot mics. I imagine if you put your ear right up next to someone’s lips singing it wouldn’t sound so good either. It all sounds better if it brings a little “air” with it, from more of a distance.
I get the distinct feeling that most home studio people like us have no idea what most of our mics really sound like. When people say an AT4050 is “bright and harsh” for vocals, they mean “…it’s bright and harsh from 3-4 inches when close micing vox” in their relatively bad room. Try it from 18" away in a good room and it’ll sound much better.
Unless you have a decent sounding room it’s better to record in a dead room ( add electronic/digital reverb in the cans for a vibe ) and add reverb in the mix.
Most domestic rooms sound geranium ( or whatever flower is replacing ‘sh1t’ this month ) A sleeping bag booth is great for recording vocals as vocals don’t contain bass and thus don’t need that kind of extreme treatment
if you don’t wanna go the sleeping bag route then, yup, make some 6 foot high frames and a ceiling for them and fill them with 4" rockwool slabs. cover with mice cloth. You vocals will suddenly be devoid of that horrible smear all those hideous reflections cause and will be MUCH EASIER to mix as they’ll be a squllion % clearer
Yup. Recording in a bad sounding room is a lot worse than mixing in one. You can always treat the room and remix or go and mix somewhere better. But the recording is there for posterity. 
how’s the boat btw
Hi there Steve.
How much you would need to treat your room acoustically to do good sounding vocals and ac guitar depends on how crappy it sounds to begin with.
I remember some old songs from blue which sounded like he was sitting in a huge bomb shelter with the mic 3 meters away from him while he was actually sitting very close to it.
In such a case you have to do something about the room to make it sound at least acceptable.
If your room sounds normal; IOW pretty dead and with very little or no audible reverberation then there is less need for treating your room.
In these circumstances clever use of a gate set as a mild expander either in hardware or software is probably enough to get that “dead” studio vocal booth sound.
Set it so that it dampens the noise floor 12-16 db with a 200ms release and with subtle enough threshold that breaths get through too and you should be good to go.
Do this on vocals but not on ac guitars as this is much harder to get just right on them.
On these do manual noise gating.
That is what I do at home and the vocal sound I have on myself, Runa, Silje and clients is good to very good IMO
One thing though: do NOT track vocals and ac guitars with your nearfield speakers on.
The spillover from the speakers into the mic per track might not be very bad as you say, but if you do this on say 4 ac guitar tracks, 4 backing vocal tracks and 2 lead vocal tracks you WILL get into serious trouble mixing it.
All the best, Kim
Very well said 
I have had good results in untreated rooms with one of these things
http://www.dolphinmusic.co.uk/product/8708-se-electronics-the-reflexion-filter.html
This is the first one I found when searching, there are cheaper ones out there.
Good description
What I hate is when I’m in the middle of a take and the AC/heater comes on, ruining it. So I get up and shut if off.
Then I wake up in the morning and go, “Why the f-uck i it so hot/cold in here?” and then I realize I forgot to turn the AC/heat back on when I was done 
LOL… That happens here all the time. I have a oil fired boiler that I shut off to rid the recordings of the jet engine sound.
Classical (aka “acoustic”) musicians - piano, quartet, what you will - perform (and record mostly) in untreated rooms. But they tend to be great rooms. Large rooms - sometimes Very Large. In country mansions and palaces and the like. And mostly with fanstatic wood floors and stages. The quality of these rooms is judged not by their relative deadness or lack of modes, but by the subjective judgement of the quality of sound when the instruments are played. It’s a naturally good sound, if not exactly uncoloured.
It’s not where we are though. Personally I’m convinced by the notion the best room would be a park sans chirping wildlife.
My recording spaces have all been pretty small and I only (and I mean “only”) record acoustic guitar and vox. I learned the hard way that sound absorption treatment was essential to me getting anything recorded that I would dare try to sell to somebody. It’s all about control. How could I think about EQ and reverb if I didn’t have something reasonable to start with.
For an afternoon’s entertainment I now go to music stores and watch and listen as folks attempt to judge the reletive sonic merits of expensive acoustic guitars in booths hardly bigger than a phone-box. Ha!
How much a mic picks up an untreated room?
It depends entirely where in the room the mics are.
Cheers!
Great reading here. Thanks all for the informative discussion.
I’ve read (and I do) for the basic poorly treated bedroom studio:
Voila - Studio 2, Abbey Road.
Well almost (__/)
…(=’.’=)
How’d that get there!?