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MQA

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mansr said:
To show that, one would first have to define what deblurring means, something MQA have not been able to do. If, for sake of argument, deblurring is a real thing, MQA is still unnecessary. Whatever it is, the labels could perform it and distribute the processed files as standard FLAC. Of course, then Bob Stuart wouldn't collect royalties from DAC sales...
Click to expand...
Well, as you and Archimago have shown, it's worse...MQA actually introduces more delays....it actually blurs if anything.
 
nostromo said:
That only works if it can be shown to be superior to LPCM, objectively...e.g. deblurring actually occurs (measurably across the spectrum).
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If the blur comes from the filter in the ADC and there as many filters as there are ADCs, how does the MQA processor know which ADC (or dozen ADCs) was used in a particular track to apply the correct contra-blur?

And the answer is...


Either that or Meridian is using its customary apodizing filter with a more catchy name.
 
tuga said:
If the blur comes from the filter in the ADC and there as many filters as there are ADCs, how does the MQA processor know which ADC (or dozen ADCs) was used in a particular track to apply the correct contra-blur?

And the answer is...


Either that or Meridian is using its customary apodizing filter with a more catchy name.
Click to expand...
Paul McGowan, in a posted video on this thread, said that while he didn't like MQA overall, he though that "MQA's analysis of popular recording chains," was cool.
 
This is the "short" filter from Meridian's Ultra DAC:

517MerUltfig03.jpg

Meridian Ultra DAC, Short filter, wideband spectrum of white noise at –4dBFS (left channel red, right magenta)
and 19.1kHz tone at 0dBFS (left blue, right cyan), with data sampled at 44.1kHz (20dB/vertical div.).
https://www.stereophile.com/content/meridian-audio-ultra-dac-da-processor-measurements

Tested with 44.1kHz-sampled white noise, the Short filter had a gentle rolloff above the Nyquist frequency (half the sample rate),
this shown by the vertical green line in fig.3; but with a full-scale 19.1kHz tone (cyan and blue traces), many aliasing products are visible.
Reducing the level of this tone by 3dB gave a much cleaner-looking spectrum (fig.4)—this filter,
which resembles that used by other MQA-compatible processors (footnote 1), is "leaky,"
but relies on the fact that musical signals with full-scale content above 15kHz or so are rare.
 
tuga said:
This is the "short" filter from Meridian's Ultra DAC:

517MerUltfig03.jpg

Meridian Ultra DAC, Short filter, wideband spectrum of white noise at –4dBFS (left channel red, right magenta)
and 19.1kHz tone at 0dBFS (left blue, right cyan), with data sampled at 44.1kHz (20dB/vertical div.).
https://www.stereophile.com/content/meridian-audio-ultra-dac-da-processor-measurements

Tested with 44.1kHz-sampled white noise, the Short filter had a gentle rolloff above the Nyquist frequency (half the sample rate),
this shown by the vertical green line in fig.3; but with a full-scale 19.1kHz tone (cyan and blue traces), many aliasing products are visible.
Reducing the level of this tone by 3dB gave a much cleaner-looking spectrum (fig.4)—this filter,
which resembles that used by other MQA-compatible processors (footnote 1), is "leaky,"
but relies on the fact that musical signals with full-scale content above 15kHz or so are rare.
Click to expand...
In the 90s, gentle slope filters were thought the best. Now they are derisively called "leaky" and near brick wall filters are in vogue.
 
DimitryZ said:
In the 90s, gentle slope filters were thought the best. Now they are derisively called "leaky" and near brick wall filters are in vogue.
Click to expand...

Yes, Bob Stuart stuart is a dinossaur that wasn't able to keep up with the times...
 
tuga said:
This is the "short" filter from Meridian's Ultra DAC:

517MerUltfig03.jpg

Meridian Ultra DAC, Short filter, wideband spectrum of white noise at –4dBFS (left channel red, right magenta)
and 19.1kHz tone at 0dBFS (left blue, right cyan), with data sampled at 44.1kHz (20dB/vertical div.).
https://www.stereophile.com/content/meridian-audio-ultra-dac-da-processor-measurements

Tested with 44.1kHz-sampled white noise, the Short filter had a gentle rolloff above the Nyquist frequency (half the sample rate),
this shown by the vertical green line in fig.3; but with a full-scale 19.1kHz tone (cyan and blue traces), many aliasing products are visible.
Reducing the level of this tone by 3dB gave a much cleaner-looking spectrum (fig.4)—this filter,
which resembles that used by other MQA-compatible processors (footnote 1), is "leaky,"
but relies on the fact that musical signals with full-scale content above 15kHz or so are rare.
Click to expand...

That's horrible!
 
Where's that vaccine against MQA now that it has been verified to be an infectious scourge of music replay?

Oh, the anti-vaccer wants us not to make the vaccine universally mandatory. Free speech and all.
 
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