Advice on an apartment mixing/editing studio in Brooklyn

Dear Forum, I have a small editing and mixing studio in my apartment here in Brooklyn. I would really like to understand what's going on acoustically in my room, and am posting here in hopes that you may be able to help me figure some things out. My room is 11 ft wide X 12 feet long. The ceilings are 8.5 feet. The walls are typical apartment drywall and hardwood floors. The unusual thing is that one side of the room is unwalled and opens into a larger 16X19 ft. room, and I have put up some screens and bookshelves as a divider between the two spaces. I have attached photos and a floor plan as a reference. I have treated my space by putting two broadband bass traps (4 inches thick) in the two corners, from the floor to the ceiling. Since the opposite wall does not exist (as it opens into the larger room) there are no other corners to speak of. I have put high frequency absorbtion panels on the wall behind my desk, suspended from the ceiling above the mix position, and in the front and back ceiling/wall joints. There is a window that runs along the 12 ft. wall- there is no absorbtion here other than some blinds, which are largely ineffective, I would guess. Attached is a graph of the bass frequency response of my room. I used the test tone CD available on the Real Traps site which goes up in 1 Hz increments from 20-300 Hz. Since I do not have an SPL meter, i used an Earthworks QTC-40 omni directional mic at the mix position, ran it through a pre, and into ProTools where I took level measurements from the Waves PAZ meter. I did not bother to graph each frequency point, but can asssure you that the graph does accurately represent the overall trend of the room's response, at least according to my testing method. Perhaps this measurement method is flawed? It seemed to make logical sense to me, but if there is a reason it would be skewed, please let me know and I'll try again using a proper SPL meter! I am not so finesssed at interpreting the significance of all this data, but it seems that there are significant peaks at 50 Hz, 120 Hz, and 260 Hz. Also, no significant nulls, at least as I read it. The range of difference is 17 db from highest to lowest above 50 Hz. I also did a pink noise test and analyzed the response, again using the Waves PAZ frequency analyzer and the Earthworks mic. This showed a fairly flat response, +/- 10 DB from 40-Hz-16 kHz. There was a slight bump in the 40-60 Hz zone. That's all the data, so here are my questions!! 1. Are the results of the pink noise test and the sine tone test at odds with each other? Why did the peaks in the sine tone test not aappear in the pink noise test? 2. Are the peaks in the sine tone test something I should be concerned with? The 17 db difference from 50-100 Hz seems worrisome. I should say, however, that I generally have no problem with the bass in my mixes- I usually get it right on, with some tweaking here and there. 3. The problem I do have with my room is with the high frequencies. I have the treble tilt on my monitors raised 2 db (shelf at 4 kHz), because if I don't, my mixes end up sounding too trebly and upper mid-rangey. What could be causing this? Too much high frequency absorbtion? 4. What is the acoustical effect of the unusual layout of my space (ie- having the larger adjoining room?) Should I treat the other room at all? If so, how and with what? 5. Are there any other tests I can do to find acoustic anomalies in my space? How can I make this space as good as I can possibly get it!! If you have read all of this and have any advice to offer, I would greatly appreciate it, and would gladly buy you a beer (or a 6-pack!) if you ever come to Brooklyn! Many thanks and cheers, Andrew

part of the problem is the nearly square space... this will certainly reinforce certain modes within it, although having the open top on the screen-side wall probably helps a bit by allowing some of the bass to escape. one of the differences between pink noise and the sine wave test will be the resolution and weighting of the frequencies involved and thereby excitation of room modes. using the Real Traps CD should be fine. the lower frequencies are much harder to control so you may need more trapping in the other 2 "corners". you might also try lifting the book cases off the floor by a foot or so to let some low frequencies out into the other space. the screens can stay put as they don't have substantial isolating value... the high frequencies may be a problem because of the absorption but you also have the back wall reflecting right back into your listening position so add some absorption there to see if that helps balance it.

hi Glenn, Thanks for the reply. I should probably say that I don't understand why the bookshelves and screens would effect the bass all that much. Perhaps the books and stuff on the shelves scatter some of the high frequency energy (a good thing, right?), but I can't imagine that they cause a lot of bass resonance. The screens are basically just simple wooden frames with a paper-like cloth over top of them. Of course, I could be completely wrong, in which case I would appreciate being corrected :oops: Here are a couple photos showing what the bookshelves and their "corners" look like... Do you think that there is sufficient mass here to cause LF accumulation? Cheers, Andrew