en:wiki:anhang:anleitungen:the_repeated_stereo_pairs_method
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| en:wiki:anhang:anleitungen:the_repeated_stereo_pairs_method [27/09/2016 20:05] – [Step 2: Measure and Correct] matt | en:wiki:anhang:anleitungen:the_repeated_stereo_pairs_method [28/09/2016 19:39] (current) – [Step 2: Gain Management and the LFE Channel] matt | ||
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| * apply delay adjustment to XO2R to account for delays found using mic alignment tool | * apply delay adjustment to XO2R to account for delays found using mic alignment tool | ||
| + | === unix (cygwin) script to copy workspaces === | ||
| + | |||
| + | An example which copies LR to the 3 fresh workspaces above, run from the parent directory | ||
| + | |||
| + | <code bash> | ||
| + | for target in LC LSL LSR | ||
| + | do | ||
| + | mkdir ${target} | ||
| + | cp LR/XO*.dbl ${target}/ | ||
| + | cp LR/ | ||
| + | sed -e " | ||
| + | done | ||
| + | </ | ||
| + | |||
| + | If using shared prefilters (e.g. for manual IIR on the subwoofer) then place these in a separate common directory. | ||
| ===== Measurements ===== | ===== Measurements ===== | ||
| Line 78: | Line 93: | ||
| For each of LR, LC, LSL, LSR | For each of LR, LC, LSL, LSR | ||
| - | Open the workspace | + | * Open the workspace |
| - | + | | |
| - | Run a log sweep | + | |
| - | Run macro 1 | + | |
| - | Run macro 3 | + | |
| - | Compare inverse curves against pulses, run "phase extract" | + | |
| - | Iterate over macro 4 & macro 5 until an acceptable result is achieved (NB: it is advisable to use the same parameters on the reference L channel in every workspace) | + | |
| If there is a non zero delay between XO2L and XO2R (i.e. the mic alignment tool did not report 0 offset) | If there is a non zero delay between XO2L and XO2R (i.e. the mic alignment tool did not report 0 offset) | ||
| Line 176: | Line 190: | ||
| ==== Step 2: Gain Management and the LFE Channel ==== | ==== Step 2: Gain Management and the LFE Channel ==== | ||
| - | COMING SOON! | + | This configuration is summing multiple input channels into one subwoofer output channel as well as applying a +10dB gain increase to the LFE input channel. If you simply use the convolver cfg above to do this, you will digitally clip the subwoofer channel during this process. This diagram illustrates the signal chain |
| + | |||
| + | {{http:// | ||
| + | |||
| + | This means there needs to be some gain adjustments performed on each channel both before and after summation to avoid clipping. In particular note that the optimal implementation is likely to require an awareness of gain structure across your signal chain as it may leverage the input sensitivity and downstream amplifiers. | ||
| + | |||
| + | One jriver centric implementation when using a 5.1 output format is; | ||
| + | |||
| + | Making Room for Summation and Adjusting the LFE channel | ||
| + | |||
| + | * move a PEQ block above the convolver | ||
| + | * add an " | ||
| + | * add an " | ||
| + | |||
| + | Recovering Gain after Summation | ||
| + | |||
| + | * move a PEQ block below the convolver | ||
| + | * add an " | ||
| + | * adjust downstream output gain/input sensitivity on the subwoofer signal chain to recover 15dB relative to the main channels | ||
| + | |||
| + | Note that this implementation allows headroom of 5dB (in the LFE + low passes) before digital clipping will occur. A theoretical worst case signal will require about 3dB of additional attenuation (and subsequent recovery) to pass through cleanly. This sort of signal is exceedingly rare (non existent?) so it is a decision for the user as to how much headroom to leave. | ||
en/wiki/anhang/anleitungen/the_repeated_stereo_pairs_method.1475006740.txt.gz · Last modified: 27/09/2016 20:05 by matt