Wikipedia:Reference desk/Archives/Entertainment/2022 May 23

= May 23 =

Dynamic range
I get high-resolution music files from ProStudioMasters.com (and elsewhere). On their website, when you get the details of an album, they have added a new tab named "measurements". On that tab is a column labeled "DR" which must mean "dynamic range". I'm used dynamic range expressed in decibels. However, the files I've checked have DR ranging from 5 to 12. The ones with DR 5-7 sound terrible and the ones with DR 10-12 sound great.

I don't think this number (5-12) can be decibels. Does anyone know what it is, and how it translates into decibels? Bubba73 You talkin' to me? 03:51, 23 May 2022 (UTC)
 * It's a ratio; see Dynamic range:
 * Audio engineers use dynamic range to describe the ratio of the amplitude of the loudest possible undistorted signal to the noise floor, say of a microphone or loudspeaker. Dynamic range is therefore the signal-to-noise ratio (SNR) for the case where the signal is the loudest possible for the system. For example, if the ceiling of a device is 5 V (rms) and the noise floor is 10 µV (rms) then the dynamic range is 500000:1, or 114 dB
 * 2603:6081:1C00:1187:38BE:68C7:DC39:B5B9 (talk) 04:58, 23 May 2022 (UTC)


 * Yes, but are these figures the base-10 or base-2 ratios? I don't think they can be base 10.  Bubba73 You talkin' to me? 05:39, 23 May 2022 (UTC)
 * One more digit 0 base-10 means (by definition) an increase by 10 dB. If the figures were base-2, the increase would be only slightly more than 3 dB. --Lambiam 11:33, 24 May 2022 (UTC)
 * They should be standard dB, 10 log_10(power), but the ratio is really something like max-to-RMS, so the values are lower than you'd expect for SNR and depend quite a lot on the piece of music. --Amble (talk) 18:14, 24 May 2022 (UTC)
 * The figures that I've seen at the website (ranging from 5 to 13), I don't believe can correspond to the base-10. The ones around 10 have much more than 10 dB of dynamic range. Bubba73 You talkin' to me? 01:34, 26 May 2022 (UTC)
 * The DR numbers for CDs or audio files seem to be really more of a crest factor: the difference between the maximum and RMS loudness across the file, in dB . The true dynamic range or SNR would presumably be much higher since the noise level or quantization level should be much lower than the average power in the music. --Amble (talk) 22:03, 23 May 2022 (UTC)


 * I haven't heard of crest factor, so it may be that. I'll try to ask the company.  Bubba73 You talkin' to me? 01:35, 26 May 2022 (UTC)


 * I asked the company yesterday, but I haven't heard back. I don't think it is crest factor. Bubba73 You talkin' to me? 20:31, 26 May 2022 (UTC)

I got a reply from the company:


 * Peak = Maximum signal level of any sample (0 dBFS = maximum)
 * RMS = Average overall signal level
 * DR = Relative strength of peak vs. RMS for the loudest parts of the song. This may be helpful to determine the amount of dynamic range compression applied to a recording.

So "DR" is some sort of measure of dynamic range, but it doesn't seem to be the traditional measure of dynamic range in decibels. Bubba73 You talkin' to me? 01:15, 27 May 2022 (UTC)
 * That’s the peak-to-RMS ratio, or crest factor. —Amble (talk) 02:38, 27 May 2022 (UTC)


 * One can express "relative strength" as a ratio, but in many contexts the customary method is to use decibels. Is there a reason to think these values are not given in dB? --Lambiam 09:25, 27 May 2022 (UTC)


 * Well, I don't know how crest factor relates to what I think of as dynamic range. I'm used to dynamic range comparing the highest to lowest sounds, not peak to RMS.  It is comparing the peak at one point to the average across the song, which is different from the dynamic range I'm used to.  Bubba73 You talkin' to me? 14:17, 27 May 2022 (UTC)