The following is the measurements excerpt from my upcoming evaluation of the Marantz AV7702:
The AV7702 includes Audyssey XT32 audio calibration, and it is also Audyssey Pro calibration capable. I began the calibration procedure by running a simple XT32 calibration, positioning the mic included with the AV7702 on a tripod at the ear height of 3 listening positions. Audyssey, as usual, did a good job with speaker distance calculations; and it also correctly identified a speaker that was wired out of phase. It also had me adjust the individual level of the subwoofers, making level matching between the subs easy. XT32 identified the front stage as all large speakers, which is not optimal for these speakers. While in theory they can reproduce bass down to around 30 Hz in room, the speakers are not designed nor able to handle the bass dynamics of movies or demanding music.
I used REW software and my Crossland Labs calibrated measurement microphone at the same 3 positions used during the XT32 setup, to measure the spatially averaged frequency response of each speaker with XT32 equalization bypassed and then with XT32 EQ set to reference, which is the recommended setting for normal use. Image 1 shows the measured response of the entire system with the XT32 settings but with EQ bypassed. The results are shown with 1/3 octave smoothing for clarity, and the LFE channel was measured at a -10 dB relative level for correct behavior with multichannel PCM signals. Dynamic EQ and Volume were disabled, as was loudness management.
We can see the level matching is not particularly good, with about a 5 dB variation among the channels. The front stage, as mentioned previously, has low level bass extension to around 30 Hz, but the center speaker in particular had audible distortion playing the bass portion of the test sweeps. The subwoofers show reasonably good extension but with a significant suckout from 50-60 Hz. The overall response trend is very good for an unequalized system, however, showing a slight midrange prominence in some channels but a fairly well behaved high frequency rolloff which is desirable in listening position measurements. However, mainly because of the suckout, the average subwoofer levels were lower than ideal. The 2 surround channels share the suckout since they were crossed over to the subs at 100 Hz by XT32.
The average of all speakers over all positions is shown in image 2.
It shows good performance overall for an unequalized in room response, but with a slight lower midrange prominence and somewhat weak bass. The HF rolloff beginning just above 2 KHz is fairly close to the ideal in room rolloff of 1.5-2 dB/oct above 1.5-2 KHz, but the ideal in room response should also feature a gently elevated bass of 3-6 dB below around 200 Hz.
The next round of measurements shown in image 3 were made with XT32 set to reference EQ, again with the calibrated microphone at the same positions used in the XT32 setup.
The level matching is better with the exception of the left surround, which measured a few dB higher than the other speakers. The subwoofer response is improved, though there is now a slight peak just above 40 Hz.
The average of all channels at all positions is shown in image 4.
It's interesting to note that, while the slight jogs of the unequalized response have been smoothed, the overall response still shows some problems. For instance, the bass range, instead of having the desired gentle lift below 200 Hz, instead shows a slight depression. There is a depression around 2 KHz, and above that the lower treble is a bit higher than ideal and the upper treble is rolled off too steeply.
I then ran the Audyssey Pro calibration, which requires the Audyssey Pro kit and license, neither of which is inexpensive, unfortunately. The Pro calibration allows more flexibility than XT32, allowing mild curve shaping. In addition, the Pro microphone is a higher grade and individually calibrated, and bass management is handled better and with more options.
As is my normal practice, I used the curve shaping feature to get the responses closer to an ideal in room response of a gently elevated bass and controlled HF rolloff. Also, not unusually for me, I was not entirely happy with the results from my first Pro attempt, so I made some modifications to the curve editor and channel levels until I was happy with the results. The response after the tweaked Pro calibration, again taken with my calibrated mic at the same positions as the Pro mic, is shown in image 5.
The level matching is very good, although both surround speakers are elevated by about 1 dB. The subwoofer response no longer shows the strange peak just above 40 Hz, though understandably the suckout from 50-60 Hz is not completely filled in. This is actually a good thing, because trying to completely fill in bass range suckouts often leads to more problems than it's worth. The dip at 2 KHz and peak just above is replaced with a nicely shaped, smooth HF rolloff.
The average of all speakers at all positions is shown in image 6.
The response shape is excellent, with a 3-6 dB lift at the low end and a 2 dB/octave rolloff from 1850 Hz to 11 Khz, increasing slightly above 11 Khz.
The Audyssey Pro calibration certificate is shown in image 7.
Last edited by Chad B; Yesterday at 09:43 AM.