Hello. I've posted this over at AVS as well, but wanted to get as many viewpoints as possible, giving it exposure where I can in the event there's not many responses.
So, here hoes: I wanted to get people's opinions on whether or not the following measurements are good/sufficient for a 2-channel only system; or can I expect to gain some improvements with a little more effort, time, patience and REW/possible DSP? And if so, how might I go about achieving this objective where the nulls and rises are concerned? It appears that with the Definitive Technology Mythos STs, people have reported, as have reviewers, a 'natural' rise in the area where I've stated below. So this may explain what I'm experiencing there (I guess I don't know for certain). Also, is the drop-off in the 25Hz - 20Hz region anything out of the ordinary; same question for the drop-off in the 16kHz - 20kHz range? I'm trying to get a grasp on what the accepted wisdom is regarding great, flat measurements in comparison to problematical regions. Here are the measurements I've taken:
64dB 70dB 73dB 74dB 76dB 72dB 72dB 66dB 65dB 72dB 72dB
20Hz 25Hz 31.5Hz 40Hz 50Hz 63Hz 80Hz 100Hz 125Hz 160Hz 200Hz
75dB 77dB 76dB 76dB 76dB 72dB 72dB 71dB 71dB
250Hz 315Hz 400Hz 500Hz 630Hz 1K 1.25K 1.6K 2K
73dB 77dB 80dB 84dB 85dB 80dB 74dB 70dB 67dB 60dB
2.5K 3.15K 4K 5K 6.3K 8K 10K 12.5K 16K 20K
I've cut and pasted the following post I placed yesterday for a little context on how I came about the measurements. It is here:
It all began with a friend of mine's purchase: a pair of Def Tech Mythos STs. I somewhat chronicled it in the speakers forum a few weeks back, trying to figure out how to cross-over his SVS SB12-NSD sub with his Mythoses, while running an Antimode 8033. I think since then, we've got it sitting pretty good; and running REW in his space shows that we've probably done about all we can do. It does sound very nice, though.
I've since picked-up a pair of the Mythos STs as well for a 2-channel-only system. Wonderful speaker, BTW (but I'll maybe talk about that on the Mythos forum)! I also have the same SVS sub as my friend, running the Antimode 8033 as well.
I have done measurements with the right speaker's gain dial at about 9:30, and the left speaker at about 10:30 (the R is about 4.5 ft. from a side wall; the L about 7 ft. from the other side wall, which then opens-up, or fires into/toward an archway where a dining/kitchen area with equal space as my listening room resides. So, there's quite a bit of cubic feet that needs to be pressurized. Now, the SVS sub is on the back wall beside my couch/listening position at nearfield. At the moment, I've set the phase at around 90-degrees (I tried 0 and 180 as well, but honestly could not tell much of a difference here), the gain around 1:00, and the crossover at 75Hz. After fiddling with measurements in order to calibrate the speakers/sub (once landing on the above) so they'd both be 75dB, I ran test tones using an SPL meter, C-weighted and set for slow for the bass, mids and highs from Stereophile's Test CD2.
Thus far, in this configuration, from 20Hz to 20kHz, things are pretty good overall (though I've no doubt they could be better...just not certain how to tackle it yet). Across the spectrum, it is admirably flat (within +/- 2dB) for the exception of the following: The bass starts to roll off at 25Hz, then drops like a brick before registering at 20Hz (down about -9dB). I'd like to get a better response from my bass, seeing that I essentially have '3 subs', but am uncertain how to tackle this, either. I have a nasty -10db dip for some reason between 100Hz - 125Hz; a +9dB rise between 4k - 6k; and then the response rolls off from 16k - 20k. All of this is with the Antimode 8033 in the chain.
BTW, my form of amplification isn't via an AVR; it is a Rega Elicit 2-channel Integrated without bass management capabilities.
Anything offered is greatly appreciated. Like I say, it sounds wonderful so far, but like everyone, I'm curious if it can be improved. Thanks!
