Increase volume of Classic Rock CD's

[chris1379]

I have a collection of old and new music on my phone. I usually just put it on shuffle when I’m listening in the car. Some of the older songs that were originally mastered for vinyl have a much lower volume and require me to turn the volume up and down, depending on the song. When I open one of these in Audacity, the overall volume is lower but there are scattered peaks close to 0db. All I want to do is raise the level by a few dB. I think the limiter function can do this but is there a wrong or right way to use it. I’ve tried Hard and Soft limiting, combinations of both and even Soft Limit twice. The “Boston” CD is a good example.

Thanks,
Chris

[DVDdoug]

If you LIKE the sound of classic rock it’s better to use ReplayGain/MP3Gain/WAVgain or Apple Sound Check, etc., which will automatically match the volumes (mostly by reducing the volume of the louder songs) and without compressing the dynamics.

I have an iPod that “lives” in my car and Sound Check works pretty well. On the computer I use ReplayGain with Winamp.

Note that these automatic volume matching tools make ONE linear adjustment before the song (or album) starts so the original dynamics are preserved. In the car, I still end-up turning up-and-down some highly-dynamic Broadway Musical soundtracks and the same thing can happen with Classical music. But most rock is fine.

Limiting is a kind of dynamic compression, and probably the “best way” to get loudness with minimal side-effects. Note that dynamic
compression is NOT related to relationship to file compression such as MP3. MP3 can have side-effects and but dynamic compression is not one of them. In fact, MP3 has wider dynamic range than vinyl (or CD.)

The limiter (with make-up gain) can get “loud” enough to completely kill the dynamics and destroy the sound (depending on the settings). But, the current version of Audacity uses look-head so even the hard-limiter setting doesn’t clip or distort the wave shape. (There are older versions that will clip, but it was improved some time ago.)

When I open one of these in Audacity, the overall volume is lower but there are scattered peaks close to 0db.

Limiting the “scattered” peaks should have very little effect on the sound but if you boost by more than about 3dB it might start sounding like boring constant-loudness modern music.

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There are two issues - The [u]Loudness War[/u] was happening in the analog days (and Motown was “winning”) but it didn’t really kick-into high gear until they started using digital processing. With digital processing they could go louder and louder and that became the preferred style of production.

Some (but not all) CDs that were originally released on vinyl have been re-mastered to make them louder. (Re-mastering doesn’t have to involve compression or over-compression.)

Then if you’ve actually digitized vinyl, the vinyl cutting & playback process alters the wave shape making some peaks higher and others lower. (MP3 does the same thing to some extent.) Those short-term peaks don’t affect the sound of the dynamics. But if you digitize the vinyl, those new-higher peaks limit how loud you can make it without clipping so it won’t be as “loud” as a digital original. This can make the vinyl “measure” more dynamic (less compressed) than the digital version even if they were made from the same digital master.



P.S.
If you do use limiting and you want to compare the “sound” of the original to the limited version, run the Loudness Normalization effect to match the loudness (on temporary copies) before comparing. It may take a couple of tries to get a target-loudness that doesn’t push the peaks into clipping.

[chris1379]

It better to use hard or soft limit?

[Trebor]

I have a collection of old and new music on my phone. I usually just put it on shuffle when I’m listening in the car. Some of the older songs that were originally mastered for vinyl have a much lower volume and require me to turn the volume up and down, depending on the song. When I open one of these in Audacity, the overall volume is lower but there are scattered peaks close to 0db. All I want to do is raise the level by a few dB. I think the limiter function can do this but is there a wrong or right way to use it. I’ve tried Hard and Soft limiting, combinations of both and even Soft Limit twice. The “Boston” CD is a good example.

Audacity’s compression/limiting are one-band operating over the entire audio spectrum.
Multi-band compressors produce a better result with mixed music, (e.g. no pumping).
There are free Multi-band compressor plugins which work in Audacity on Windows, e.g.
[ You may still have to use a limiter after compression to maximize the volume ]

[chris1379]

Thanks everyone. I may use a little EQ on some recordings but not this time. I tried to find an area of several tracks that was high but without the spurious peaks. from that, I used Amplify to find out the level. A few samples told me I could amplify things by 3dB. I then used Hard Limit with a 3dB input gain and set to -.2dB limit. Seems to work well. Keep in mind, this is not an archival copy of the music but helps level things out in the car. The leveling feature in the phone doesn’t work well and lowers the volume. This causes other problems with my car stereo because Honda added a non-defeatable loudness feature that kills the bass when the voume control is at or above a specific level.