i suppose your right.. thanks.. im assuming the meter is pricey.
Well, it has to be generalized in car audio as the space required for any low frequency operation is much larger in respect to wavelength. But basically, I have all of my information in excel. I have all of my formulas and such that when I calculate for my values, I can figure for which direction to go with physical dimensions and such to control each of those factors. Each profile I have, I calculate for 20 different listening positions and get different response curves from each position. I use that to calculate the difference in each location to account for loss and gain in the vehicle. Regarding seats, tunks, windows and such, I use the understanding of frequency dependancy vs shape of the areas, in which each freqeuncy will have it's own characteristic to say, wrapping around a seat, and affects the output gain independantly of the others. And for windows, and other factors, those are figured as a dampening factor when closed, or part of the acoustical suspension and compression chamber when open. The thing is, again, this has to be generalized because LF response is way to large to not have resonances in which these factors have a lower sensitivity to the environment when such a space is utilized. It is more important in larger acoustical areas, but still is calculated for with losses and such in the vehicle for a better idea of whats going on. In a normal design, the basic diemnsions are the most important, and factors other than resonance propagation and dampening are less a factor due to the amount of compression within the "chamber" of the vehicle. Each resonance has it's own characteristic, in which it has its own response curve, just as the ear does, so each one, up to 20 positions are done for a general response curve of the vehicle with high regard to compression and reflections, and nominal regard to diffraction.
LOL I like that.
