Bass Boost Q preset bandwidth

[pollenflug]

Hi there, maybe someone can help me find what I'm looking for. I'm trying to determine what the Q width is for the Bass Boost effect in Audacity. I'm running Windows 7 and installed the exe installer. I know I can't change the Q bandwidth of the Bass Boost, just the frequency and how many +/- dB i want to change. Is it 1 octave or 2 octave or 1 and 1/3 octaves bandwidth? Thanks for your help in determining this.

[steve]

Bass Boost is no longer shipped with Audacity. Among the reasons why it has been discontinued is the fact that if too much boost is inadvertently applied, it will permanently damage the audio (non-correctable distortion).

Bass Boost was a second order low shelf filter with a slope of 1.0. The frequency setting was the half gain frequency.

[pollenflug]

Thank you. Guess I should update so I'm not tempted to apply bass boost even moderately.

[steve]

Guess I should update

That would be a good idea. You can get the latest version of Audacity here: http://audacityteam.org/download/

There is also a Nyquist plug-in implementation of the Bass Boost effect available. The plug-in version does not have a "Preview" button (so you may want to test settings on a short section before applying to the entire track) but it also does not have the problem with clipping. If you are working in 32 bit float format (default) then in the event that you "over cook it" and exceed 0 dB, the Amplify effect (or Normalize) will be able to bring the level back down to the valid range without any permanent damage.

The filter properties of the plug-in version are identical to the original version (but without the clipping).

[DVDdoug]

Thank you. Guess I should update so I'm not tempted to apply bass boost even moderately.

That should be OK (except maybe there was a defect in the original bass boost effect).

But, after you do anything that might boost the volume, you should normalize (adjust the volume for peaks to 0dB or less) before saving, especially if you save (export) to an intger format (such as a regular 16-bit or 24-bit WAV file).

Audacity won't clip internally, but most formats are limited to 0dB and your digital-to-analog converter is also uses integers and is limited to 0dB.

Bascially 0dB is defined as the biggest integer number (positive or negative) you can have, given the number of bits. So a 0dB 24-bit file will have "bigger numbers" than a 0dB 16-bit file. But everything is normalized by your driver, so the 24-bit file is not louder than a 16-bit file. (Floating point audio uses a completely different system, where 0dB is defined as 1.0 or -1.0.)

[steve]

(except maybe there was a defect in the original bass boost effect).

Yes there was. Even when working in 32 bi float the BassBoost effect would clip at 0 dB - that is, peaks over 0 dB would be cut off at 0 dB.That problem does not apply to the Nyquist plug-in version.

[Sonic Blaster]

i do find the bass boost handy, when in a mix i am not sure exactly what freq's to adjust in a "thin mix". usually i boost the bass 1 db, gain 1 db. then notch/cut a band at a time to taste. Every track is different, some have sub-bass, some not, etc.
I also find that this little boost seems to "glue" a mix rather than compression; where compression glues things from the bottom up, the added EQ fills in gaps horizontally between bands...i tend to lay off the low end going in recording, to preserve headroom and keep space and add later.

[steve]

The current version of Audacity replaces the old BassBoost effect with "Bass and Treble" http://manual.audacityteam.org/o/man/ba ... reble.html
It can be used in much the same way as the old BassBoost but is more subtle (the filter curve is less steep) so you may need to apply a bit more boost than you would with the old effect. As the name implies it also has a treble control, and it can also be used to reduce the bass (or treble) if required.