[LAU] Room acoustic sound analysis

Hello LAU, While I have not been active on this list in a long time, I have been watching from the side stage and it's nice to see the string of various information and experience still flowing thru the LAU community. I'll get to my questions as they relate to the subject title in a sec but firstly, a little back ground on some significant changes I have going on and how they may relate to the furthering of open source audio... I have left the corporate grind and world of regular income for purposes of pursuing my all time passion. I have not a pot to piss in nor a window to pitch it out of in terms of capitol and am largely doing it on faith! My core products are fretted instrument and amplifier / music related electronics repair, recording and demos, small PA system rentals and also working as a musician for hire, primarily doing my solo thing. In another post I will speak to my dilemma of being unhappy using Sonar 8 on Windows Vista and looking for some possible encouragement to consider going totally open source! I have rented a large warehouse type space (2600'sq) in the Nth Cali foothills and within there are several spaces dedicated to the various products I alluded to. The main room that we do live music in is a good size, approx. 30'w x 40'l with 17' ceilings. It's predominantly drywall and stud construction and also with a 17'x10' metal roll up door. It has a concrete floor with industrial carpet covering it. I have just described something of an acoustical nightmare, likely only topped by an aircraft hangar with corrugated iron walls and roof! :) We have been doing some live stuff thru a PA in this room and it's a sure fire way to reveal how the room reacts. The room produces some high freq (2k - 5k) boosts as well as some 150 to 400hz bumps. While I have implemented some baffles to reduce live high freq bounce, these only serve to deaden the room and not change tonal characteristics. How I go about changing the mechanics of the room will be dictated largely by economics but in order to assess this, I'm looking to to some spectrum analysis. Has anyone set up a laptop and microphone and open source apps and performed this to some success? I need a tone generation source as well as an analysis tool. It needs some bias adjustment for mic and sound card inherent response I should think. That said, it does not need to be a perfect tool. If I can get some form of reliable, self referenced measurement, that would give me something more than the guess work I am currently using from my head and my ears. TIA for your input and ideas. Russell