8.The design constraints for MultEQ were that it (1) must fit within a small portion of the DSP so that other processes can also run and (2) it must use FIR filters because of the well-known artifacts that IIR filters cause particularly in the time domain response. As it turns out, these two requirements are contradicting. In order for FIR filters to be effective and capable of correcting to low frequencies, they must consist of several thousand coefficients (taps). The problem is that the CPU power required increases with the number of taps, hence the dilemma. What we did at Audyssey was to come up with a different way to partition the frequency axis so that we can use fewer taps and yet not completely give up on low frequency resolution (and therefore low frequency correction). This allows us to take a 512 tap filter that would normally have a resolution of 94 Hz (meaning that any peak or dip narrower than 94 Hz would be missed) and significantly improve its resolving power. The resolution of the filter actually varies continuously with frequency and starts at around 10 Hz. Does this mean that MultEQ can correct an arbitrarily narrow peak or dip at 30 Hz? Of course not. The reality is that in the MultEQ XT version found in receivers, we can correct broader features below 100 Hz better than narrow ones. For example, a lump that is half an octave wide at 50 Hz can be fixed. A narrow dip or peak that is 1/3 or 1/6 octaves wide and centered at 30 Hz will be improved, but not eliminated.
(以上芯片技术问题原文照登~~~)
A good guideline is to look up the frequency response of your speaker and find its lowest frequency (or the point where it drops off -3dB), then add about 20Hz to that to use as the crossover setting. That said, the crossover's slope (i.e. how quickly it transitions) is pretty steep, so you might be able to get away with adding as little as 10Hz to your speaker's lowest reproduceable frequency. Start with 20, then tweak to preference to get the best transition.
9.我应该改变Audyssey所测的喇叭距离吗?
Audyssey似乎可以侦测喇叭距离与实际距离相当接近，但有些人仍认为这不是喇叭中间音像最佳设定。你可以用Digital Video Essentials测试碟中一系列测试音（这些测试音音场都是在喇叭正中央），一次改变设定距离约半英呎慢慢感觉音场聚集在中央（意即在这样设定下喇叭相位正确）。如果声音变得越分散或者难以聚焦，那表示改变距离设定后让喇叭与其他喇叭相位不正确了。
While Audyssey does seem to properly detect speaker distances close to their actual physical distances, some have found that this is not the best setting for between-speaker imaging. The calibration disc has a series of test tones that are placed equally between channels. Using these tones, you can tweak speaker distance a half-foot up and down to listen for the setting that makes the sound "hang" in space between the speakers (which means it is in phase at that setting). If the sound becomes more diffuse or harder to pinpoint, it is because changing the setting is putting it out of phase with the other speaker.
要改变喇叭距离设定、面对前墙依照下列步骤去做：
A)在前左声道与中央声道播放特定频率测试音、然后一点点慢慢改变设定值前后移动中央声道、看看是否在某距离设定时、让你感觉声音更聚焦在两支喇叭中间！然后在前右声道与中央声道重复这动作，选择一个让两边声道听起来最佳的设定值作为中央声道距离设定值。
B)在右前声道与右环绕声道中间播放测试音频，然后上下调节右环绕喇叭距离，找出侧墙喇叭距离的最佳位置，因为环绕声道位置通常高于主声道喇叭、或许无法找到一个完美的设定，但你应该可以找到一个从侧方向来较佳的音场位置！
C)重复B)的动作在左环绕部份，如果你只有5.1配置、那到这里你就完成设定了
D)For 6.1/7.1 setups, put your receiver into DPL-IIx Movie mode and play the tone between the right surround and the rear surround (since DVE only has 6.1 tones), or change DVE to the DTS track and use DTS-ES Matrix mode, then bump right rear surround distance up and down slightly until you hear solid placement of the sound between the two. Then repeat using the tone between left surround and rear surround, changing the distance setting for the left rear surround. If you only have 6.1, bump your rear up and down to listen for the setting that works best with both tones.