Stretching the dynamic range down to gain dynamics

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I am digitizing some LP’s I don’t find on Tidal. Audacity works fine, thank you.

Conversion is made by an old SoundBlaster soundcard. Settings: input on 100% (no clipping), 96 kH. Only post prod: de-dlicking. Usually I export to Flac 24 bit. Interestingly, when I digitize an LP which is on Tidal, the result I obtain sounds better than the Tidal version (clrearer, more colour). I fear the DSP used by firms to wipe out the flaws of analogue technology are detrimental to the music.


My point here: the dynamics. LP’s are said to offer at least 60db (whereas I remember that in the sixties le upper limit of turntables seemed to be at 56db). Yet on the recording level meter of Audacity I read -30, -36, -42 at best between the tracks… Actually, we knew already in vinyl times that the industrial product we bought seldom held the promises.

Hence a first question: did others experience the same limitations while digitizing LP’s?


So one could consider enhancing the dynamics in the DSP while exporting the digitized record. Unfortunately, adding gain makes no sense, since the peaks of my records often reach -2 db. What would be needed ist a process for stretching the original dynamic range towards the bottom, say moving the -40 level to -50. In that manner the dynamic range would be enhanced and the noise floor lowered. I guess this should be possible without quality loss since the project data are stored using 32bit floating point.

Hence the second question: is that a good or a bad idea? Is there some software out there, which offers such a tool?

Reto

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I expect that the apparent lack of dynamic range is due to the vinyl’s surface noise. The meters is Audacity respond quite slowly, so occasional crackles are likely to push up the meters during “silences”.

In my opinion, artificially “stretching” the dynamic range will do more harm than good.

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, when I digitize an LP which is on Tidal, the result I obtain sounds better than the Tidal version

Different phono cartridges sound different. The frequency response is different and some cartridges will distort more on loud passages… It’s analog!

(clrearer, more colour)

Sorry, but I only understand words with real meanings, and things that are identifiable and measurable, like noise, distortion, and frequency response. :wink: “Clearer” could be more high frequency information. “Color” is usually related to distortion.

I fear the DSP used by firms to wipe out the flaws of analogue technology are detrimental to the music.

That’s possible. Automatic click & pop reduction can sometimes remove some high frequency information.

LP’s are said to offer at least 60db (whereas I remember that in the sixties le upper limit of turntables seemed to be at 56db).

60dB is pretty good. -60 dB is probably inaudible under “normal” conditions and I’ve never heard a record that didn’t have some audible noise. I think that’s sort-of “under ideal conditions” with a very-good pressing.


Yet on the recording level meter of Audacity I read -30, -36, -42 at best between the tracks…

The background noise on records varies. Back in the vinyl days classical and jazz recordings were known for having better quality, and I suppose that also meant lower noise (compared to rock & popular records). Your cartridge may pick-up some hum. Your preamp will add some hiss & hum. There will be some rumble from the turntable. Sometimes noise gets-into your soundcard through the computer’s power supply, etc. It all adds-up. Welcome to analog! :stuck_out_tongue:

What would be needed ist a process for stretching the original dynamic range towards the bottom, say moving the -40 level to -50. In that manner the dynamic range would be enhanced and the noise floor lowered.

Dynamic expansion makes loud parts louder and/or quiet parts quieter (the opposite of dynamic compression).

A Noise Gate is an extreme example of downward expansion. You can try a noise gate plug-in, or search for a expander plug-in. [u]GoldWave[/u] ($60 USD after free trial) has a Compressor/Expander and there is a “Reduce Quiet Parts” preset. (GoldWave is sometimes confused about the definitions of compression & expansion but if you start with the presets you should be able to figure it out.)

I guess this should be possible without quality loss since the project data are stored using 32bit floating point.

I wouldn’t worry about that. Anything that alters the digital data can’t be considered lossless but if you like the results you can consider it an improvement. :wink:

Hence the second question: is that a good or a bad idea?

There’s no harm in trying it and it should be fun! . I actually built an expander back in the analog days and it did reduce the noise during quiet passages. But, it was too “aggressive”. 1:2 expansion over the entire dynamic range was built-into the chip and at the time I didn’t know how to get-around that. I haven’t played around with expansion since then. (And you can’t really reverse “loudness war” compression & limiting.)

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I’m strongly minded to agree - and I digitized a lot of vinyl LPs and 45s :sunglasses:

I prefer to retain the original dynamic range that the recording engineers laid down (mostly they do a great job).

Apart from Audacity the other tool I used was Brian Davies’ excellent Clicj Removal - costs a little, but does an excellent job and can save huge amounts of time. See this sticky thread: Click/pop removal - ClickRepair software

Peter

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A free* expander plug-in which works in Audacity on Windows couture.

[* it’s not necessary to buy the full featured version ]

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Thank you all for your comments and suggestions. I conclude that the limited dynamic range I obtain while digitizing LP’s is not shockingly bad… I will certainly give the plugin a try, at least for the fun of the try.

@ DVDdoug
Yes, the descriptors I am using are subjective and it takes time to build an agreement about their meaning. As I used them, they are very imprecise…
With ‘colour’, I mean a better differenciation between the tone colour of various instruments (Klangfarben), not oveerall coloration.
With ‘clearer’ I mean a better individuation of the various sounds, which compose the music, also low frequency notes like those of the bass.
These qualities are not measurable but certainly usable in a comparison. Actually, comparison is the lowest level of measurement available and unfortunately it ist also the highest level on which qualities can be ‘measured’.

Reto

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If you can hear any crackle during “silent” parts, then that will be the dominant cause of the limited dynamic range. Using a really good crackle remover will probably do more to restore the original “perfect vinyl” dynamic range than anything else, though you need to take some care to not use any kind of noise / crackle reduction too aggressively, or it will damage the sound. I’ve read good reports of Brian Davies’ Click Removal (commercial software - not free but reasonably priced and a free trial period).

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See this sticky thread: Click/pop removal - ClickRepair software

But only after I’d already treated a fair few time-consumingly by hand with Audacity’s Repair tool …

Peter