Im looking for the best spot in my room just prior to starting to treat it. Of course, I need to find the best spot first and get some base line measurements to compare to. I used a calibrated ECM8000 from Cross SPectrum Labs. I pointed it straight up at the ceiling at 90 degress to the speakers at the listening position. I of course used the appropriate calibration file for this positioning.
So, thats what I did, here it is. I may be able to still find a better response yet but I cant go further till I get some sort of advice on any issue I may have from 5khz on. Waterfalls irrelevant at this stage, a total mess as you would expect in a empty untreated room!
Now I am quite concerned at the drop off from 5khz on. Is this in any way to be expected? This is a empty room bar a couch and speakers and a small 10U rack unit. It measures approx. 19.2ft x 10.6 ft x 7.8ft high. It is a roomed off section of my garage which is about four times the size of this room. The walls are 10mm plasterboard. A balance I thought of very carefully to get just enough isolation to not cause disturbance, and at the same time give me a bit of help with modal activity. I am set up across the short wall.It is VERY obviously live as hell in there at the moment.
I have been through everything I can think of that may be causing this drop off in my set up, but I have come up with nothing that would be having an effect like this. To me, it looks like the kind of high end drop you may expect from over treating a room with broadband absorbtion, with no consideration to retaining any of the higher end of the spectrum!! Other than this, its not as bad as I expected and most of the issues I think standard broadband trapping will go a long way to fixing.
First part of the treatment will be filling the entire rear wall built in trapping area of 14 inchs with 10kg/m3 fiberglass, and some diffusion to top it off.Then the 6 inch joist cavity in the ceiling will be filled (32kg/m3 in there), the entire ceiling. Then front corners and first reflection points and additional wall/ceiling corners.
The speakers are Quested H108's approx. 6 inchs off the front wall and this plot is the measurement for one speaker only. They are spaced apart around 4.5ft and...triangle, 38%...you all know the drill! That is roughly the set up so far.
I really need some advice on this before I continue then find the enormous energy put into something like this renders my results void because I have some sort off issue in the high end! You know...measure twice, cut once or something like that. Thanks guys!