Bassboosting, Split to Mono FIRST?

Hi, I’m a basshead and been enhancing my music for couple of years now, suddenly some dude told me that you have to split the track to MONO first. Then boost the bass to 0db. So when it’s back to Stereo again the plotspectrum will read +6db but will be 0db since the bass is a mono signal.

Which way is correct?

My method that I’ve been using is:

  1. Amplify the song to about -6 to -8db
  2. Use the Equalization feature and boost the frequencies I want boosted
  3. Try my way until I see 0db in the Plotspectrum while maintaining the song undistorted.

    So. should I first split it to mono? Or going stereo from the beginning?

I guess that you are not talking about folk music.
What sort of music? How was it recorded? Is it professionally mastered (commercial recordings)?

It’s mostly rap, recorded in 320kbps.

If it has been professionally mastered, then the low bass will be centre-panned mono, so no need to mess with the channels before boosting the bass - just take care to not cause clipping. Applying Normalize, and then the Limiter effect after boosting the bass (make-up gain enabled) will help to keep the overall loudness level up without clipping.
(see: Audacity Manual and Audacity Manual)
If the bass becomes “mushy”, you may be able to sharpen it up a bit by using the “Soft Clipping” setting in the Limiter effect, though I would go for the “Hard Limit” setting as a first choice.

No… In the end, the “digital maximum” is 0dBFS in both channels and it doesn’t matter how you get there.

The bass is normally mono (centered). Almost all commercial recordings are mixed that way already. That allows you to take full advantage of both woofers and get the full 0dB maximum from both channels at the same time.

If you are multi-track recording, almost all channels will be “mono” with the bass guitar and bass drum panned to the center (along with the lead vocals) and the other instruments panned across the “soundstage” as appropriate.

The important thing whenever boosting anything is to normalize after boosting. Since most commercial releases are already normalized (maximized), you can’t boost without clipping/distorting. Audacity can go over 0dB, but most formats can’t, and your digital-to-analog converter is also hard-limited to 0db. If your peaks go over 0dB, you can normalize before exporting, so your file won’t be clipped. …That means if you start with an already-normalized recording, you end-up reducing everything except the bass (for more relative bass), and you have to make-up for it with your analog volume control.

As Steve also says, you can also try some limiting. Limiting allows you to boost everything except the existing peaks so you can boost the overall volume without clipping the peaks. Limiting is a kind of dynamic compression, so the dynamics will be reduced as everything is pushed toward the same volume. But if you want the bass “constantly loud”, try some limiting. (Make sure you are using the latest version of Audacity because the Limiter was greatly-improved recently.)

It’s a good idea to normalize after limiting too, although with the right settings the limiter can set/limit the peaks to 0dB. …It’s a good idea to normalize, or at least check the peaks, after any processing. You can check the peak by running the Amplify effect, because it will default to whatever change is needed (up or down) for 0dB peaks. then, you can cancel the Amplify effect if you just want to check.

Great replies! I understand now. Don’t you think the limiter will like ruin the song if it boosts all the bass. Just a stomach feeling that the “Punch” will fade away slightly. Well, I guess I’ll just have to find out that by myself.

Anyways, I go through parts of the song with plotspectrum where I’ve marked about 1 second and read the value there how “strong” the bass is. And trying to keep it about 0db.

But I do not think the Normalize thing works if I’ve amplfied DOWN the song about -8db and boosted the bass.

See, if I get the mids & highs down to -8 or something, then boost the bass and the bass are about +3db or something. The whole track can still be 0db and no clipping occurs if I use the Amplify and tweak it to zero clipping and checking with the Find Clipping plugin,