Originally Posted by buckweet
Haven't gotten that far yet to do the crawl. I'm not shocked to hear you say that about room modes.. Last year when I built the marty's, it was pretty much dead silent in the middle of the room. Walk to a corner and you go deaf.. It's pretty crazy to hear everything vibrating apart around you, yet you hear/feel nothing. The kitchen is about 40ft from here and the bass is powerful out there, again within the room pretty much nada.
So this room is really bad... It's just when I moved them to the living room where I get a good experience with the Paradigms, I was still disappointed.. Granted I couldn't put them in the exact spot where the paradigms were sitting due to the massive size of the titans (big blocks vs tall skinny). So perhaps that was my issue out there too, I hope!
Above, Matt touches on the paradox of running large full-range speakers at full-range...as LCRs. Due to the physics of room modes, the speaker location where room modes would permit the speaker to provide strong LF at your listening position may well not coincide with where an LCR speaker has to be to work as an LCR.
You describe the classic demonstration of the first axial node in the middle of your room. When I attended the THX school back in 2002, it was still a week long intensive course, especially in acoustics...and taught by none other than Anthony Grimani! The classroom work was done in our hotel, but the rest at Skywalker. One amazing thing he did was set up demonstrations of axial modes. He placed a very big sub (on a furniture dolly) in a corner of a large room in the hotel. He sent it the frequency of the first axial mode in that room. Wherever you stood, it was deafening...until you stepped into the middle of the room...where it was silent. Take one big step forward or aft, and it was deafening again. He also demonstrated this with much higher frequencies with a teaching aid he made using a 1.5' or so length of PVC pipe in which he had a very small microphone. The mic was rigged such that he could slide it fore and aft along the length of the pipe. Knowing the length of the pipe, we could calculate the first axial mode...and confirm it by sliding the mic (kind of like a trombone) and find that there was no sound at the mid point at that frequency.
What are the shapes and dimensions of the two rooms, and where in each are you listening/measuring?
My point in suggesting you do the LF crawl is only to try to verify that there is nothing wrong with the Titan. The position you find (assuming you are not listening/measuring in the middle of the room) where the Titan has good acoustic LF response will almost certainly not be the optimal place to place an LCR. Does that mean that the Titan is a bad choice? No! It just means that you may have to use bass management to achieve smooth/linear response. I think the Titan is incredibly sexy looking, and I would kill to have those two waveguides which I'm sure sound fantastic. But...like your room, the L/R main locations in my room (just at the edge of the s 10' wide AT screen) have a huge, horrible node centered at 43Hz. 20 years ago I was trying to figure out why I had poor bass with subwoofers at those locations. After attending the THX school and acquiring a measurement capability, I confirmed the problem.
So, LF is not the only benefit to the Titans. If you can get them smooth down through 60Hz, cross them there using xt32, and call it a victory! Presuming your subwoofers are in acoustically friendly locations, xt32 will smooth them beautifully. You can then use your RTA utility and the MEQ Editor app to smooth out response a bit more and manipulate to the target curve of your choice. You can make modest tweaks for the LCRs. The LF will likely be smooth, so you will only need to adjust sub trim/gain to lift the LF region and splice region to emulate the Harman curve. I'm a huge proponent of the Harman/Synthesis curve. All that, plus Dynamic EQ, and you'll be in heaven.
My "compromise" to that terrible node was to use HTM-12s for L/R mains, and cross them at 60Hz using the process in the previous paragraph. The results are seamless. I never miss the HTM-12s not reaching below 60Hz because the splice with the subs is excellent resulting in linear response (+/- 3db or better) down to 22Hz or so. The SMPTE mixing room/dubbing stage spec is linear to 25Hz. Achieving that at a minimum is where I want to be.
Hang in there. Keep working it.