I just finished the tests...rather than use AVIA, I used a series of individual tones from the BINK Audio Test Tones CD (http://binkster.net/extras.shtml
). I wanted to be as accurate as possible with the frequencies, so I thought that this might work better. Using specific frequencies above, at and, below the set crossover points would give me ample time to measure the SPL. And with out introducing any variables with a sweep.
I calibrated the SPL meter such that with fixed volume from the 2807, it read -75db. That would be my reference point to measure from. I placed it on a tripod, 6 feet away from, and centered between the two front speakers (DefTech SM350's). This was also 5 feet away from, and just to the right of the SW (Pro Sub 1000).
Running series of LF tones: 20hz, 25hz, 31.5hz, 40hz, 50hz, 60hz, 70hz, 80hz, 90hz, 100hz, 125hz, 160hz, 200hz.Speakers set to SMALL tests
1) Set up: All speakers set to small
. LFE mode
. Speaker crossovers at 100hz. I pushed the crossover up to 100hz from my usual setting of 60, so that I would have some more range to measure, since below 60hz, the 350's are not going to be that great.
With the SW turned OFF, playing just the fronts: Pretty flat from 200hz down to 125hz. At 100hz there was the beginning of rolloff (about -3db), at 90hz it was about -8db and at 80hz it was about -12, at 70hz about -15. At 60hz I was down to the -19db point. I stopped measuring at this point, as below that the 350's freq response would be less than stellar, anyway.
Turning the SW ON, and measuring its output, I started from 20hz and worked up the scale. Fairly linear up to 90hz, then slight rolloff begins (about -2db). At 100hz we dropped to about -4, at 125hz it was -14, at 160hz it was -28. I stopped there.
2) Set up: All speakers set to small
mode. Speaker crossovers at 100.
Almost the exact same results... give or take.
Meaning, that regardless of LFE or LFE+MAIN, the speaker setting of small
determines how bass management and crossover point are handled.Speakers set to LARGE Tests
3) Set up: All speakers set to large
. LFE mode
. Speaker crossovers at 100.
With the SW turned OFF, playing just the fronts: Pretty flat, little variance from 200hz all the way down to around 40hz, then started dropping slightly (about -3db), at 31.5hz about -5, and at 25hz it was -9. At 20hz, it was off the chart low, and pretty much garbage. But, the 350's are not really full range speakers, so I'd expect them to struggle down there. The did, however, remain flat WELL BELOW the crossover setting of 100hz - showing that when speakers are set to large, in LFE mode, they play the full range. I'm expecting that in this mode there will be no output from the SW.....
Turning the SW ON, and measuring its output was pretty easy... there was NONE. As expected, with speakers set to large
, the only thing sent to the SW would be LFE signals. And, none of this content went through the LFE channel.
4) Set up: All speakers set to large
. LFE+MAIN mode
. Speaker crossovers at 100.
Again, the results were almost identical to the LFE mode in #3, pretty flat down to 40hz - with the same roll off beyond that.
Now, turning the SW on, and measuring its output. There was output!!! Again, I started from 20hz and worked up the scale. Fairly linear up to 90hz, then slight rolloff begins (about -3db). At 100hz we dropped to about -5, at 125hz it was -14, at 160hz it was -28. I stopped there.
So, this shows that with speakers set to large
, and LFE+MAIN
mode set, you are getting the lower frequencies from both the mains *and* the SW.
Hope this helps with the understanding of how these modes work.
Now, I'm going to go watch the Stanley Cup finals... don't tell me who won. I DVR'd the game to do these tests
If something looks stupid, please cut me some slack. Been working on this post in between a lot of other things going on tonight. I think it's reasonably accurate... if in concept only.