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發表於 2008-11-27 22:32
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VI. During Calibration
A. Do not make any sudden noises during the “chirp” measurements.
1. Audyssey measures for a few milliseconds (ms) after each “chirp” is finished, but then has to wait for the DSP to calculate,
so the microphone is not active until a few ms before the next set of chirps.
B. Do not stand in between the speaker and the microphone or anywhere that the sound is either reflected off of you or absorbed by you.
1. The natural room acoustics must not be substantially affected.
C. Be prepared for the “chirp” measurements, as they are quite loud, and can startle you.
D. If a phase warning is shown, check the speaker wiring, and press “Skip” to continue with the calibration.
VII. After Calibration
A. Raise the speaker crossover settings, if desired.
1. Raising the crossover frequency from the calibrated setting does not affect the channel correction implemented by Audyssey.
2. Lowering the crossover frequency from the calibrated setting is not recommended.
a. Audyssey will not provide correction to the satellite speakers lower than the frequency it measures as the -3 dB point.
3. Setting the speakers to “Small” with a 60 Hz – 80 Hz crossover is a good starting point, assuming the calibrated crossover setting is 60 Hz or lower.
4. For additional details about the speaker setting process, see “Note 1” below.
B. Raise the low-pass filter setting (usually incorrectly identified as a crossover) of the LFE subwoofer in the receiver / processor to 120Hz, if allowed.
C. If the satellite speaker distance settings (excluding the subwoofer) were not measured accurately, and are markedly different from what you get with
a tape measure, start all over.
1. Incorrect distance measurements for the satellite speakers indicate a procedural error, and the associated EQ results are likely to be poor.
D. Do not change the distance setting of the subwoofer.
1. Inaccurate subwoofer distance settings are the result of measured delays between the time when the receiver outputs the test tone and
it is received at the microphone.
a. Any filters and/or active circuitry in subwoofers can delay this signal.
b. Audyssey simply measures the time delay and compensates for differences in the arrival time of sound from the various speakers and the subwoofer.
It is best to compensate for these differences regardless of why they occur.
2. The subwoofer / satellite speaker time alignment blend is based on this measurement.
3. Inaccurate subwoofer distance measurements usually occur when the subwoofer’s Low-Pass Filter (LPF) is not disabled.
a. The LPF, by nature of its design, introduces additional delay to the signal; Audyssey detects and corrects for this delay.
E. Disable any Night Modes, DRC (Dynamic Range Compression), and D. Comp (Dynamic Compression) in the receiver /
processor as well as the DVD / BD player.
1. If these features are not disabled, they could possibly cause adverse interaction with Dynamic EQ and Dynamic Volume.
2. You may need to temporarily turn off MultEQ to access these parameters in your receiver / processor.
3. You may also need to select a specific soundtrack type before a given parameter will appear in the menu for adjustment; check the manual to be certain.
F. If your receiver / processor has the THX Loudness Plus feature, turn it off if you plan to use Dynamic Volume.
G. Select one of the target curves created by Audyssey.
1. In a THX system, the “Flat” curve should be used when THX post-processing is on, and the “Reference” curve should be used
when THX post-processing is off.
2. In other systems, the “Audyssey” curve should be used for listening to movies, and the “Flat” curve should be used for listening to music.
H. If desired, trim adjustments can be made in the receiver / processor, so that all speakers measure at 75 dB with an SPL meter (set at “C” and “Slow”)
using the internal test tones. See “Note 2” below.
1. Audyssey will monitor these changes.
2. The changes are monitored so that Audyssey and its features (Room correction curves, Dynamic EQ and Dynamic Volume, etc.) work as designed.
3. If you were to make changes to the settings on a subwoofer, Audyssey would have no knowledge of this, and those features would not operate as designed.
Note 1:
Audyssey does not set the crossovers; it simply measures the -3dB frequency point of each speaker.
This information is passed to the receiver / processor for calculation of the speaker settings and crossover points, if applicable.
Unfortunately, Audyssey does not report the -3dB frequency point measured for each speaker.
The only information available to you is whether or not the speaker was designated “Large” or “Small”, and any crossover point selected for “Small” speakers.
Receiver / processor manufacturers use a specific Frequency Decision Point (FDP) to classify speakers as “Large” (full-range) or “Small” (less than full-range).
The selection of the FDP varies among manufacturers, and may be 40 Hz, 80 Hz, or another frequency.
If the -3 dB frequency measured by Audyssey is below the FDP, the speaker is classified as “Large’.
If the -3 dB frequency measured by Audyssey is above the FDP, the speaker is classified as “Small”, and a crossover frequency is selected.
Each receiver / processor has various crossover points from which to choose.
Typically, the first crossover setting above the -3 dB point measured by Audyssey is chosen.
For example: If your receiver has crossover settings of 40, 60, 80, 100 and 120 Hz, and the speaker is set to “Small” with an 80 Hz crossover,
that is an indication the - 3dB point is somewhere between 60 and 80 Hz.
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發表於 2008-10-17 15:39
