Really simple basement studio

Hey guys, my first post here! I've been lurking around this forum for a couple of days now, and I've decided to ask for help/opinions (even if my needs might seem kind of basic compared to the fantastic studios I've seen here): I'm moving in about 1 1/2 months and on my new home (near Lisbon, Portugal) i have a room in the basement I'm planning to use to record myself and no more than demos for small upcoming bands from around here, I'll explain everything in detail: About me: I have a daytime job, and fancy myself an indie musician by night. I have an engineering degree, so math is no problem, in case somebody wants to make a point that way. I've recorded one album which I released through Tunecore, without many sales, but i really couldn't care less about that (electric guitar instrumentals are a niche...) My use of the studio: I'm a big fan of good guitar simulation (i know, i know, not the same as the real thing, suffice to say I believe there's a good effect out there for every guitar sound, just not one for all) so, I don't record guitar with amps. My hardware setup is fairly good (lynx two and focusrite preamps here), so i get along like this. Bass is recorded direct with a preamp also. Drums are taken care of with Superior 2 and a huge "frankenstein" e-drum kit built from both a roland and yamaha kit. The only parts recorded with live sound would be vocals and acoustic guitar. The location: this room is in a basement (check the attached pictures) with a vehicle access ramp to the left, with two medium sized windows facing that way, a big garage beyond the door and ground past the two remaining walls. I have no problems whatsoever with neighbors or noise, so i won't be soundproofing the room, just applying acoustic treatment. Unfortunately, the room is square (4.7 long by 4.5 wide by 2.8 meters high), small, and I can't stand being inside confined spaces, so making the room smaller with stud walls etc is really out of the question. My idea: after reading a lot, I think that a LEDE design with a few changes might work - I'm thinking of making a mostly dead (medium to high frequencies) wall behind the speakers, with some 10cm thick foam, a diffusive surface in front (the door side) with irregular stonework, and treating the corners with bass traps. The floor would be formed by those click on wood panels (don't know how to call them in english) with a dampening sheet below, over the existing ceramic tiles. I believe that most first or second reflections would be scattered by the stonework wall and that I wouldn't need foam on the side walls... Budget: well, something like 1000€ - I'm pretty handy, so i'll make the work myself, maybe even building a couple of low frequency ressonators for the corners - not sure yet (I've read the math and believe i can adjust them to my room modes)... I'm sure I'm missing a lot of things, but i really want to keep it simple. Oh, forgot this: monitor wise, I have a pair of near fields, with stands, that I'm planning to place a little over one meter from the "foam wall"... Well, please do tell me if I'm making any huge mistakes with this...and if I'm getting in over my head on this.. Thanks!

Welcome! I suggest going with insulation based treatments instead of foam as the insulation types tend to be more effective overall. Since it sounds like you just want room treatments so treat the corners as shown and first reflection points. Put the monitors upmclose to the front wall and and absorber between them them. Treat the back wall, ceiling, and in front of your desk (avoid floor reflection). If you want to eliminate some of the squareness consider soffit mounting the monitors and using slats. This keeps things alive, forces some mode shifts, and makes for better speaker / boundary response.

Shouldn't i include some diffusing surfaces? I was under the impression that to improve the stereo imaging on small rooms some sort of diffusion should be used - maybe i read it wrong...

it depends - if you are using the slat/diffusers types it is better than a pure "diffuser" because of the phase effects of the QRD versus something like a slat resonator or MLS diffuser where absorption is part of the equation as well as angles etc. patchwork absorption is also diffusive so keep in mind there are a number of options for "diffusion" including polys.