Quote:
Originally Posted by batpig 
JJ -- although all the speakers are identical, the differing acoustic positions within the room can have a dramatic effect on low end output. That's why Audyssey actually measures the speakers and how they respond in your room as opposed to just going by the manufacturer's specs.
The Takes are spec'd down to 115Hz but the bottom end will change in room depending on how much bass reinforcement they are getting from nearby boundaries or other properties of their physical position. Are the front speakers pulled out from the wall, whereas the surrounds are wall-mounted? This is one example that could explain the discrepancy. Also, just due to the room shape you could be sitting in a slight "null" for one or both of the fronts that is sucking out a bit of the bass as the mic "hears" it.
Also, there is less granularity in the crossovers once you move away from the 80/90/100 mid-zone. From 120Hz the next crossover is 150Hz, so it's possible your fronts are measuring just above 120Hz and then the receiver has to bump it all the way up to the next option (150).
As a test, you could try swapping the fronts and the surrounds and re-running Audyssey, and see if you get similar results. Note that you can get slight changes with different Audyssey runs if you don't use the exact same mic positions -- the crossovers are calculated based on all the measurements. Sometimes repositioning the speakers slightly and re-running will change things, you might be able to get the fronts to clock in at 120Hz if they are right around there.
Regardless, I would raise the other crossovers up to 120Hz and call it a day.
JJ -- although all the speakers are identical, the differing acoustic positions within the room can have a dramatic effect on low end output. That's why Audyssey actually measures the speakers and how they respond in your room as opposed to just going by the manufacturer's specs.
The Takes are spec'd down to 115Hz but the bottom end will change in room depending on how much bass reinforcement they are getting from nearby boundaries or other properties of their physical position. Are the front speakers pulled out from the wall, whereas the surrounds are wall-mounted? This is one example that could explain the discrepancy. Also, just due to the room shape you could be sitting in a slight "null" for one or both of the fronts that is sucking out a bit of the bass as the mic "hears" it.
Also, there is less granularity in the crossovers once you move away from the 80/90/100 mid-zone. From 120Hz the next crossover is 150Hz, so it's possible your fronts are measuring just above 120Hz and then the receiver has to bump it all the way up to the next option (150).
As a test, you could try swapping the fronts and the surrounds and re-running Audyssey, and see if you get similar results. Note that you can get slight changes with different Audyssey runs if you don't use the exact same mic positions -- the crossovers are calculated based on all the measurements. Sometimes repositioning the speakers slightly and re-running will change things, you might be able to get the fronts to clock in at 120Hz if they are right around there.
Regardless, I would raise the other crossovers up to 120Hz and call it a day.
Thanks for the excellent reply! I think you're exactly right, as there are accoustic reasons the speakers whould measure differently. The surrounds are wall-mounted, fairly close to the corners, the center is on a shelf of a TV stand/AV cabinet, and the fronts are on speaker stands almost 2 ft. from the wall. I suspected this was the reason, but I just wanted confirmation that such a disparity wasn't unusual. My own ears can hear the the difference in the bass from the Audyssey test chirps.
Also, good information on the crossover jump from 120 to 150; I didn't notice that. So far, I have not been bothered by the 150 crossover. However, if I start feeling like the directionality of the bass from the fronts is a bit off, do you think this is one case where I actually can experiment with lowering the crossover and see if 120 sounds better than 150? If, hypothetically, the fronts were measuring just over 120 (and I suspect there's no way to retrieve the actual number), then there shouldn't be much of a "hole" in the bass by lowering the crossover.
Audyssey XT kicks ***....can't help but wonder what XT 32 could do for me. 
I still love my MX-700 (I've even got a backup I bought on Ebay a couple years ago) and you can have it when you pry it from my cold, dead hands. 
)
