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3rd Party Plugins - (fb2k) / Re: foo_truepeak True Peak Scanner
Last post by Case -could you please explain why does your component measure a little differnt than the built in RG? The results differ by about 0,1/0,2.Native ReplayGain scanner doesn't follow any standard. It just offers an option to upsample using a resampler and settings of your choosing.
Is there a different standard or by design those calculations are not precise (guesstimation)?
True Peak values depend entirely on the used resampling method. If you configure the built-in scanner to do the same resampling operation, the results are 100% identical.
My scanner was made to follow ITU-R BS.1770-3 recommendation. They state that for determining True Peaks a sampling rate of at least 192 kHz should be used. But higher the sampling rate the better. As I have said elsewhere, my component doesn't just resample to 192 kHz. It picks the lowest integer multiplier that reaches at least 192 kHz sampling rate. For a typical 44.1 kHz audio that means 4 x upsampling isn't enough, 5 x is needed.
Plus what exactly Clippings measured in your component mean?Any sample value that is beyond digital fullscale.
Then how does RG applying work. If we measure RG, Clips, True Peaks and use Album mode we can then use 4 options:It means same as volume adjustment. It adjusts the playback level so that each track or each album have identical loudness and listener doesn't have to touch volume settings.
- none - obvious
- apply gain
- apply gain and prevent clipping from peak value
- prevent clipping from peak value
What does apply gain really mean - does it just turns the volume up or down (usually waaay down)?
If we use prevent from clipping does it change the volume but to a degree not to produce clippings so for example it would turn the volume up by 3 but then it would clipp so it turns up by ex. 2 not to clip?The 'apply gain and prevent clipping from peak value' adjusts the level but if the peak value tells things would clip, the level is lowered just enough to keep the peaks inside digital fullscale. In track mode this adjustment is done for each track, in album mode all tracks are adjusted by the same decibel amount as much as is needed to prevent the track with highest peak from clipping.
Does the "prevent clipping" option (without applying gain) mean that if there are 0 clippings on the album it would do nothing but if there were clippings it would turn the volume of the album as much as needed to avoid clipping? In album mode would it do exactly the same amount in every track?It works exactly like that. If the peaks are below full scale the signal is not touched at all. If the peaks are too high, the level is adjusted. In track mode each track is adjusted separately, in album mode the entire album is adjusted by the same amount.
So now what would be the best way to make it louder. I use USB-ASIO DAC with foobar and DAC volume at max level so I change the volume with a manual knob othe amplifier. Would it be better to use foobars built-in Preamp (the one below RG section in the preferences) or might that produce Clips?I don't think you need to worry about hiss. Keeping DAC and Windows volumes at maximum will ensure highest signal to noise ratio to the amp, which is of course good. For ReplayGain to work it needs the headroom for the louder material, so it would be best if you didn't try to fight it. But using the preamp slider in foobar2000 is the correct way to increase the loudness of ReplayGained output. Increasing the preamp will of course make clipping more likely, but as long as it's lower than the negative gain values shown for your tracks/albums, it won't introduce any additional clipping.
So to sum it up - is applying RG an equivalent of just turning the volume knob on amp up/down or does it do something else?It works like volume knob but since it's done before the DAC it can prevent clipping of intersample peaks or floating point material that would clip in the DAC.
I'll attach an old test file that you can use to test and demonstrate the effect of intersample clipping in your DAC. If you play that file unaltered through your DAC at max volume you will hear distortions if the DAC clips. Lowering the volume will let you hear how it should sound without clipping. I have seen some super high end DACs sold that claim they have 3 dB headroom against intersample clipping. This goes beyond that so I don't think there is a DAC that can handle this without help from computer.