User manual DENON AUDYSSEY

[. . . ] These bands do not provide sufficient resolution to address many room acoustical problems. Also, parametric bands tend to interact so that changes at one frequency have undesirable results at nearby frequencies. Moreover, parametric equalization methods use a particular type of digital filter called Infinite Impulse Response (IIR) that only attempts to correct the magnitude response in the frequency domain. These filters can cause unwanted effects, such as ringing or smearing, in the time domain particularly as the bands get narrower. [. . . ] The `Front' setting uses the MultEQxt filters that were calculated for the entire listening area, but it does not apply any filtering to the front left and right loudspeakers. The average measured response from the front left and right loudspeakers is used as the target curve for the remaining 2 loudspeakers in the system. The subwoofer in this case is equalized to flat as is the case for all the settings described above. Finally, the `Manual' setting is a traditional Graphic equalizer that does not use the MultEQxt filters. However the `base curve' that was measured during the Auto Setup process, can be copied to the Graphic EQ, where you can then make adjustments to your personal tastes, again no other properties of MultEQxt are applied with this setting. 5. Why does MultEQxt correct beyond 300 Hz? There is a belief that room correction should only be applied to frequencies below 300 Hz or so because that is the frequency range in which most of the room problems occur. This belief is based on an inherent assumption that a properly designed loudspeaker will perform as desired at higher frequencies and thus require no correction. If the loudspeaker is in fact properlly designed then no correction will be applied to it. One simple fact that the proponents of this theory seem to overlook is that even the best designed loudspeakers will suffer from artifacts at high frequencies produced by reflections from nearby flat surfaces such as plasma screens or cabinets. MultEQxt performs this kind of correction when it is needed to allow the loudspeaker to achieve the performance it was designed to have. 6. My speakers are wired correctly, why does MultEQxt give a "Phase" error? MultEQxt detects absolute phase for each loudspeaker. Some loudspeakers are designed with intentional phase reversals in the drivers in order to address crossover problems. The best course of action is to simply check the wiring and press "Skip" if it is correct. MultEQxt simply reports a possible wiring reversal, it does not automatically switch the phase. 7. My subwoofer is physically closer than the distance reported by MultEQxt. Why? Many powered subwoofers do not provide the capability to defeat the built-in low-pass filter. These filters, by their nature, introduce additional delay in the signal and MultEQxt finds that and reports it. The optimum solution is to turn the filters off (often called "LFE mode" in subwoofers). If that is not possible, set the low pass frequency to the highest possible setting and leave the distance reported as it. MultEQxt will compensate for the added delay and time align the subwoofer to the satellite channels so that the optimum blend is achieved. 8. How many listening locations can be measured? The equalization performance increases with the number of measurements. Audyssey recommends a minimum of 4 with most rooms performing best with 6 measurements. [. . . ] What happens to the MultEQxt settings when the parameters are changed? MultEQxt corrects for room acoustical problems. They do change the tonal balance based on the preferences of the customer. The benefit of MultEQxt is that it allows a customer (or installer) tone control setting to work on all program material in a much more predictable way than it would on an uncalibrated system. Changes made to the crossover frequency or "small" and "large" settings of the loudspeakers do not affect the performance of the MultEQxt filters. 15. [. . . ]