Advice on Room Acoustics - RoomEQ Measurement Attached

I have a room dedicated for recording music in the classical/sacred genre. The room was recently completed. The walls and ceiling are double-wall insulated with 1/2" OSB and 5/8" gypsum. Floor is hardwood. The room dimensions are shown in image below (ceiling height is 10'). Presently the room has no acoustic treatment. I am looking for advice on treating this room bearing in mind the type of music mentioned above that is going to be recorded. We would like to maintain a decent amount of liveliness to the room. The following are images from a frequency sweep measurement using RoomEq Wizard. The measurement was made using Tapco S8 Monitors with front of speakers located 73.5" from west wall (right wall in image above) and each speaker 57" from side walls. SPL meter was the Radio Shack SPL 33-2050 located 8 feet from east wall (left wall in image above) and 7' 5" from side walls. If interested, I can upload photos of the room. Thank you, AB

Read the stickies. There is plenty of information about basic studio setup and absorbers etc.

Hi! :-) Did you measure with both speakers or only one? You should use just one. Also, the waterfall you posted doesn't show too much useful information about the decay of the sound in your room. Adjust the time resolution so we can see more time slices. You're definitely going to need some bass traping. You have many options, ie. place resonators in corners, panel traps, use THICK (5" and more) rockwool sheets spaced from the wall... etc. If you want to keep the room live and nice sounding, you could definitely take advantage of using diffusers. QRD, polys, whatever fits... You can DIY or buy some (RPG makes some nice diffusers).

Looks like comb filtering in the low end to me, and a speaker and(or mic with poor low-end response. How did you measure that? (what mic, what speaker, locations of both, levels, etc.) - Stuart -

I measured with both speakers, but did another with just one speaker. Image below shows approx. location of the speaker and SPL meter. Speaker is a Tapco S8 located 74" from right wall shown in image and center between side walls. SPL Meter is 8' from left wall shown in image and also centered between two side walls. Measurement details from RoomEQ are below: SPL measurement data saved by Room EQ Wizard V4.11 Source: FP10 #FP10 In 3&4 (PreSonus FP1, LINE_IN (Master Volume), Right channel, volume: 1.000 Format: 1M Log Swept Sine, 1 sweep using mic/meter cal file: E:\RoomEQWizard Files\RADIOSHACK-33-2050.cal using soundcard cal file: E:\RoomEQWizard Files\PreSonus FP10 Inputs 3-4.cal Dated: Apr 14, 2010 3:58:20 PM REW Settings: C-weighting compensation: On Target level: 75.0 dB Note: Recording Studio Here are images of the most recent measurement with RoomEq using only one speaker. The SPL meter is the Radio Shack 33-2050 through a PreSonus FP10. Both have been calibrated through RoomEQ prior to measurement.