In Conrad's case, it is an older computer running the LMS software, and he sets up a mic in his driveway and angles the cabinet forward. There is nothing to reflect against so it is probably quite accurate. I used to work at Rodgers Instruments and they also used the LMS software with an iso chamber and a mic and the cabinet would be mounted facing the floor in most cases. I compared my little 2x15 cabinet there and at Conrad's and the LMS plots were just about identical. I'm not sure about the other details of the testing appartus, though I could find out at some point if you really wanted to know. I think I might work with Conrad at some point to upgrade the computer that he uses for the LMS as it is REALLY old and slow.
I'll see what I can do when we get around to doing the testing Isaac. I'll let you know, but it may not be until the end of summer.
Greg
Outside? What about ambient vibrations? Even a
slight breeze across a mic will produce a significant low frequency rumble. At the typical low energy levels generated by 1W @ 1M, even a
little wind rumble can skew the response curve downward.
Blow even slightly on a reference mice and you'll see what I mean. You have a lot of the same issues with SR at outdoor venues.
However at live outdoor gigs you can scramble for wind screens, HPF's and gates to lose the rumble, no one is going to miss that <100 hz and subsonic stuff in the main mix, and the only real "problem children" are going to be vocal, guitars, and horns in a R&R/Pop/Blues type scenario.
You probably
already have the kick gated to death, keyboards are almost always DI'ed, and if the bass guitar isn't Di'ed it should probably be gated at a pretty high threshhold to avoid drum kit bleed regardless of whether you are inside or outside.
But; all of
those tricks will totally screw up attempts to get an accurate curve.
What am I missing?
