7channelfreak and I have been working on a day that fits into both of our schedules where I could come and check out his new Dirac DDRC-88A DSP and MiniDSP and get his theater tuned. We connected the Dirac from the avr into his seven channel amp and the miniDSP in between the dirac and subs. Now the fun begins! I set up the mics and took a baseline reading.
I forgot to calibrate the baseline reading to actual SPL in this measurement, but I fixed that later during the measurements.
Now I tuned each sub individually
(I prefer it this way in this scenario) and added necessary delay because the rear sub was closer than the front sub. 7channelfreak did not want the subs level matched because he didn't want the rear sub to make people's teeth chatter or bones to rattle, so level matching was not done. However, the subs bled nicely together and you can not localize them anywhere in the theater. This is helped out by lowering the upper frequencies of the back sub slightly, and being that it is already lower in SPL, you do not have to lower them that much.
This is what I measured after tuning.
Black is rear sub.
Green is front sub.
Blue is both subs.
When you get your subs time aligned correctly, the collective measurement should be parallel to the main sub which is exactly what I was able to achieve here. Or parallel to the rear sub and front sub averaged.
I personally like to tune the subs before running any room correction software for a couple of reasons. First, if you ever change anything and want to run the correction software again, you will already have your subs tuned and time aligned. Less work will need to be done by you and the room correction software. Second, I feel like manually tuning works out better with setting delays and for getting a flatter response or a house curve.
Now that the bass was done, it was time for Dirac to do it's thing. Ran nine sweeps with Dirac and adjusted the curves until there was a great response. This took a while because this was new to me and I was really nit-picking trying to get a super flat response in the upper frequencies. I was shocked at the bass boost on the low end! It looks like a crazy house curve that I would do to my theater. That flat response that I got with the miniDSP was out the window at this point, but I would have implemented a house curve anyway, probably not like that right off the bat though, hahahaha! I asked 7channelfreak if he wanted to try it out to see how he liked it with movies and then we could go from there. While he was demoing some bass heavy scenes I was checking input levels and output levels on the DSP's and the SpeakerPower amps on the back of his Captivator S2's. I was expecting some clipping on at least one device and surprisingly there was headroom at reference volumes! This to me is a great testament JTR Speakers and makes me miss my S2 that I sold not too long ago. The JTR 215RM speakers sounded fantastic at super loud volumes! The blend of them and the S2's together was seamless and addicting, meaning I wanted to hear more and more music. Hotel California by the Eagles sounded so fantastic, and I thought that it was a bluray because of the sound quality. I was shocked when 7channelfreak told me that it was just a CD. Mind blown!
After watching a few demos and listening to some music tracks, we both agreed that nothing needed to be done at this point. Here is the final chart after eq on everything.
Here is some more pics because we all like to look at pics!