studioporn

first 2 room analyses didn't turn up as much as i had hoped. combination of the software being good in the acoustics department but really bad in the software department, and getting my reference mic with the calibration info on a 3.5" floppy. it's bad enough these days when something comes on a floppy, but even worse when the metal slider is broken. so i had to rip off the slider and try on a few machines before i finally got stacey's old laptop to read the files off of it.

last night i stumbled across a free java app called Room EQ Wizard which has some really nice features and is really easy to use. below are some graphs of measurements i took in the room. there was a speaker near one end of the room doing a log sweep, and in each test i moved the mic to a different location in the room and took a reading. the graphs you see show frequency vs. amplitude vs. time; in other words, they're a very good way to visualize the overall frequency response as well as the reverberation response of the room:

the goal of a well-tuned room is to have a nice, smooth reverberation. overall i'm in the right ballpark, but there are some things that stand out in these graphs:

1. the area around 60Hz going up towards 70Hz is resonating like crazy. long after everything else has decayed, that frequency is still going strong. this will most likely need to be addressed through the use of bass traps in the corners (that's where low-frequency energy is the strongest--particularly in trihedrals, where wall corners meet up with the floor or ceiling)


2. there is also a slightly less intense, but still noticeable, spike right around 300Hz. i will probably tackle this with one or more helmholtz resonators. the convenient thing here is that 300Hz is also the area where kick drums can get boomy-sounding, so in drum rooms and other spaces where drums will be regularly recorded, it's recommended that this frequency be absorbed anyway, even if there aren't any problems there with the room itself.


3. there's a strange dip centered roughly around 90Hz and spanning as much as an octave or so depending on the position in the room. i don't yet fully understand the data here--i consistently see this behavior regardless of speaker or mic position, and have verified the data with 2 separate analysis programs and separate sets of readings. before finalizing room treatment plans, i need to do some more research to better help me interpret this particular data point.


4. the low mids as a whole could probably benefit from a little absorption. up to about 400Hz there are some peaks that jump out a little more than they should.

the really nice thing about this data is that it confirms what my ears have been hearing, which is a relatively decent reverberation save for some beefiness in the lows and low mids.