NOTE - If this is considered too long of a post for this kind of thread, I am happy to create a new one.
I have accumulated a lot of gear, these tests are done using the LR speaker from Atlantic Technology's System 250, 2200, 2400, Compact Theater Two, 350THX, and 370THX.
Another note - I am currently selling the 2200 5.0 and 250 5.0 set. For very very cheap, as you can see I have way more than I can use so I am offloading. See classifieds.
Alright - Here are measurements and notes I made as measuring. I am not a audio genius. I love to buy speakers and try them out and see what I think. I have a basic understanding of how it all works. If terms etc are confusing, I am happy to try to explain more. I don't claim to know everything and am in a constant state of trying to learn more. The notes were taking quickly as the first things that came to mind as I was A/B'ing different sets and I tried to turn those into readable words. If it seems incoherent, that is why. I am still learning to express my thoughts on listening in a way that is as objective as I can be as a fallible human.
These were some of my first uses of REW and measurement microphones.
I used the following equipment:
UMIK-1 USB Microphone - Calibrated
Samsung Chronos 7 Laptop on board sound card no calibration
Sherwood RX4503 Stereo Receiver
Graphs are 1/3 smoothing, It's easier to read and they seem to offer plenty of information to get the picture.
Objective measurements were done with the microphone and subjective measurements were done by A/B'ing with the Sherwood comparing LR speakers on these.
Speakers were placed on a homemade stand made of MDF and solid pine, with a drawer rubber liner thing in between speaker and stand.
Measurements were made on-axis at about 3' away from speaker. I did not put any acoustic panels in the room for measuring, this is my office/playing with speakers room. 12'x12'x8' door closed. I did try making walls around the measuring area with acoustic panels but figured unless i made the walls 8" thick it wouldn't have a positive impact. So I left the room reverberant.
I needed a way to show graphs from each speaker, so I show a graph for each set of comparisons. If I did each speaker in one graph it would be hard to read. If you have a combination I didn't cover, let me know.
A note about the 350/370 graphs vs the others. You see the steep roll offs. The 350 had a much more obvious sound difference from this, it almost sounds hollow in music. While playing high resolution movies you don't feel that way but in typical content, without surround sound listening modes, it will feel hollow.
Where the 350 tends to sound very very very warm (maybe too much) as obviously seen in the graph, I also had a similar sound from a pair of Jamo THX ONE speakers I had, which were also a part of the original THX certified speakers out. That very big dip in the high frequencies could be an early THX design, I don't know. I did test both LR and Center of the 350 and each had a similar graph and roll off that low. The 370 Roll off is not quite as low but does happen pretty sharply. (Don't recommend using ReEQ with THX speakers!) And the 370 sound much better than the 350 in general and I highly recommend them!
EDIT: As I study the graphs more and more, EVEN though I tried the LC and R 350's and each had a really big drop above 7-10khz I am not positive they are good. The impedance seems good when measuring with a meter and there is no obvious sounds that make me think they have gone bad, also the cones on the mid ranges are moving and there is SOME output up high so I imagine the tweeter is good. I don't know if they are malfunctioning or not...Would be cool if AT would chime in. It's just such a weird graph compared to ALL those other AT sets???

CTS2 Vs. 250
CTS2 feels a bit more musical but with less dynamics than the 250...the 250 gets a bit punchier where the CTS2 is...more open and spacious while retaining a bit more resolution. The 250 almost has a slightly condensed sound, not as spacious

2200 Vs 250
The 2200 is FAR more resolved in the high end than the 250, the female voice is front and center, that difference in the chart where the 250 has a dip and the 2200 has a peak must be the reason. I have just started to use measuring equip and its fascinating to see cause and effect. The 2200 chart shows it to play low but i felt as though the 250 had more output in the lower midbass region, like the lowest string of an acoustic guitar. Where the 2200 was more resolved, it sounded very brighter than the 250. Given the enhanced resolution, I still prefer the 2200.

2200 Vs 2400
Where the 2200 has that obvious forward vocals that is very in your face and dynamic, I feel the 2400 calms it down just a hair, sounds more balanced between highs and lows. It basically feels like they took the small drawback of the 2200 and fixed it. I suppose this could be due to the newer tweeter or crossover the 2400 got, whatever it is it is just a bit more balanced. Either way, its these forward dynamics WITH great resolution that makes these two speakers so incredibly wonderful for movies. So lifelike as when the movie shows someone knocking on a door and your pets turn their heads or run towards your own door.

2400 Vs 370
This was a bad idea, it showed me everything wrong with the 2400 haha.
The 370 is more dynamic, full, balanced, loud and invisible than the 2400. It is so much better that I am about this close to convincing myself I NEED a 8200 set so I can have the 370 sound with 2400 newer technology and materials.
As I was A/B'ing the two sets, I had a bottle of water in my hand, as I switched to 370 all of a sudden the bottle was vibrating. It's clear the 370 is a far better speaker (not just because of the bottle) and I cannot believe I got a 5.1 set for the price of my 7.0 2200/2400 combo. I also cannot believe this stuff is so hard to resell.
NOTE_GRAPH SAYS 2200 - IS 2400 AS SEEN IN THE LEGEND

2400 Vs Compact Theater 2
This is a hard call. Especially since I only have one LR of the CTS2 system. Doing an A/B of that and a 2400LR my thoughts are that the CTS2 had more midbass and invisibility, like the speaker was less obvious and the 2400 had better dynamics and impact. They were both very clear and clean sounding. The CTS was a bit warmer. Given I love the sound of warmer speakers it would be very hard to decide between these two, except that I know if it was for music only I would want the CTS2, if it was for movies, I would probably want the dynamics of the 2400

2400 vs 350
When I first switched from the 2400 to 350 5.1 sets in my living room, my first and only real impression was that at high volumes (-8db+) on movies, the 350 retained high clarity and low distortion with reference playing. The 2400 will not play as loud and clean as the 350 so take that for what it is worth when deciding between the two. Keep in mind, my room is 5000cuft, with a listening area of 2400cuft. So, in a bedroom sized listening room the 2400 is likely awesome. If I could convince myself I needed surround sound in my bedroom, I may actually go with the 2400 over my 350 set. Also keep in mind when looking at the 350, you get some different designs built in for the THX certification that offer some positive for surround sound applications.

In the end, my honest opinion, given all speakers and having had full setups of most of these systems running at some point. Including the musical and surround sound experiences I have had, here is my opinion in a list format.
1. 370THX
2. 350THX
3. 2400/Compact Theater 2 (Given a bedroom-ish sized movie space, the CTS2 is incredible bang for buck used if you could ever find a set)
4. 2200/250 - Very different sounds but both very good. The 2200 is much like the 2400 with a bit more forward dynamics. Where the 250 has a bit more balanced or warmer geared sound. The 250 Surrounds have the SAME woofer as the 350 Surrounds, though they can't play as loud and may have different crossover points that has to count for something. The 2200 surrounds are the same as the 2400 surround and are way awesome as a 5.1. I would likely pick the 2200 over the 250 as a full system just because of looks and size of drivers etc. The 250 won't get as loud and dynamic but at used set prices its incredible bang for buck and if you want a bedroom system on the cheap its a killer deal.
Here are some pics of the mic placement and speakers, the 370 looks moved but that is because I took the pic after measurement and listening. And there is only one pic of 2200/2400 cause they look the same so....




Edited by shaneb0422 - 5/19/13 at 5:14pm