Originally Posted by cannga
Sanjay's post that I found relevant to development of Dirac for CBIIIHD - the important ability to have BOTH automated and manual adjustment
Remember when I spent a few days re-assuring you that Theta had picked a really good room correction system and explained the things that Dirac was doing right? Well here's part 2, where I explain how easy it will be to use AND to custom tailor the sound to your tastes.
Jeff Hipps was kind enough to give me a detailed look at the Dirac interface and patiently explain the calibration routine. The first step was to pick the size of the listening area, by clicking on one of three graphics: a chair, a couch or stadium seats. (I'm guessing the latter is the one to pick if you a calibrating a commercial movie theatre using Dirac in a DataSat AP20.)
After clicking on the couch, we were shown a graphic of a couch with 9 dots on it. Switching between an overhead view of the couch and the front view, you could see one of the dots was in the middle of the couch at ear height, while the remaining 8 dots were spread out at different heights. You start with the first measurement at the centre of the couch (sets levels and distances), then move the mic to the other 8 locations. Each time you are done measuring at that spot, the corresponding dot on screen lights up, until all 9 are lit and you are done.
Dirac then does the hard part: spatially averaging the 9 measurements to see which problems show up in various seats in order to find out which problems can/should be corrected and calculating the filters needed to conform the response of all speakers/subs to the target curve. Remember we discussed the reason that Dirac tilted their target curve, so that it sounded 'perceptually flat' and gave more of a natural sound than a 'measured flat' response. If you like the results, great. If not, you adjust the target to your liking (a bit more bass, slight midrange bloom, subtle treble roll off, etc). Diract will try to get as close a possible to the target curve you've created.
How do you edit the target curve? Easy: clicking at any location on the default target curve creates a dot (a little round point on the curve). You can then tug on that dot to pull that section of the curve up or down. Want to keep the downward tilted bass but want a flatter midrange? Place a dot around 400Hz and another dot at 15kHz. Push the dot at 15kHz up until the section of the curve between those two dots is no longer tilted and is laying flat. Click a button and Dirac will recalculate the response to the new target. Simple as that. You notice that from 15kHz up, the response is still tilted down, but you want more of at tilt down, for that warm tubey sound. Place a dot at the top end of the response (20kHz or 24kHz), and pull that point down. Recalculate the response. And so on, using as many dots as you need (no joke) to get the precise results you want.
As an example, Jeff brought up a situation where something in the room (like an a/c vent) rattled at a particular frequency (say, 300Hz). He put a dot at that 300Hz point on the target curve, and then one dot on either side of it. He then yanked down on the middle dot to create a deep V-shape centered at 300Hz. By moving the other two dots closer to each other, he minimized the width of that V to create a really skinny notch. Recalculate the response. You've lowered the output at the problem frequency but minimzed how much it affected other frequencies. Since it is easier to notice something added (tall peak) than something is missing (skinny dip), the notch will barely be audible; if at all. But the rattle is gone. While this isn't strictly a case of EQing the sound, it is an example of using Dirac to improve your listening experience. Higher fidelity includes minimizing distractions.
So there you go: Dirac will handle the hard/boring part (spatially averaging multiple seats, calculating correction filters), and you do the easy/interesting part (adjusting the sound to your tastes).