Hello,
I am telling you about a problem that I just brought up to Denon. I'm quite worried ...
(English is not my first language. Please excuse me)
"Denon 6700H amplifier - Problem
After calibrating the amplifier with the Audyssey application, I noticed a major "bug" in the management of speaker phasing. Indeed, to the ear, there is a glaring phase difference between the subwoofer and the rest of the speakers. At first I thought it was an external problem, so I spent several days / nights checking the entire installation with a magnifying glass, wiring, filters, speaker placement, etc. Then I went through each of the amp's options, redone several calibrations; I even tested different Denon amps to compare. And I was finally able to identify the origin of the problem, I am positive, the problem is indeed with the Denon x6700h.
1. State of the problem (The only change in the HC system is the amplifier 4500h -> 6700h)
The delay correction is adjusted with the variables "speaker distances", in meters. After calibration, the values can be viewed in the software, and quite logically correspond to the results I obtained with the 4500h.
Front speakers: 3.40 m (+ - 5 cm) / Sub: 7.20 m (+ - 5 cm)
HOWEVER, I have to manually maneuver the "software distance" of the subwoofer and add 1m of delay (7.20m -> 8.20m), in order to obtain the correct phasing! And there I finally get a "normal" sound. Phew!
I would like to point out that this observation is the same in all circumstances, Pure Direct or not, filters / options activated or not. If I had the time, I could possibly highlight this record through measures. However, the difference is obvious. To realize this, I used the 2 memories (Presets) which allow you to quickly switch between different configurations. I specify that I am accustomed to scientific rigor during an analysis; taking care to vary only one variable and limit the influencing factors.
1.1 Balance sheet
I spent several dozen hours to finally enjoy decent sound. I am in total incomprehension. How can such a bug take place? I have had several amps, and Audyssey calibration has always given good results. Here I managed to detect this anomaly, but I'm not even sure that other speakers are not affected. On the bass it's easy to detect, but less so on the other frequencies. Unfortunately, I no longer have time to do more research. So, do you plan to fix this quickly? It is fundamental.
2. Assumption - Limitation
2.1 Considering the fact that the value found / displayed automatically (7.20 m) corresponds well to the value that I get with other amps, I have the feeling that there is an offset with what is displayed and the value actually taken into account by the software. It is as if the software recorded the corresponding value at 6.20 m, while it displays 7.20 m.
2.2 This may be due to a set of factors not taken into account by engineers routing the algorithm. For example, in the setting of the distance of the speakers, I noticed a software limitation (6m maximum difference between the speakers). I manage to find satisfactory values while remaining within this range, nevertheless, it is true that 8.20 m represents the admissible ceiling by the software. I therefore wonder about the link that there may be with the initial bug. However, the Denon 4500h took my Sub to 7.20m, and everything was perfectly in phase, so I have reservations about that assumption. "
I am interested in your feedback.