Audacity Forum

I found a song with the bass boosted, and it sounds perfect. I wanted to use the method used on the song for other songs, but I do not know the method and everything I have tried is not as good. The song is Lil Wayne's Krazy, and I was wondering if it was apparent what steps I should take to emulate the bass boosting method used. Bass boosting alone doesn't work, and using low/high pass filters doesn't seem to work.

I am running Windows 74, 64 bit, Audacity 2.0.5
The top track is unboosted, the lower is what I'm trying to accomplish.

I think it needs some kind of leveler because the waveform is pretty straight across.
As with the whole plot spectrum, the lower frequencies need to have a higher db and higher frequencies need a lower db.
And of course, bass needs to be increased to a peak of -27.8 db for 50 frequency.
Any help is greatly appreciated. I'm really just looking for a clean way to boost bass that won't blow my speakers/sound distorted.

You will need to boost the bass and/or reduce the treble, AND apply a high degree of dynamic compression, for example with a limiter (http://wiki.audacityteam.org/wiki/Nyqui ... er_.282.29)

The flat-top dense waveforms indicate limiting or perhaps clipping (distortion). Even the top waveform isn't what "natural music" looks like. The bottom waveform is "worse". i.e. If you record live music played with real instruments, it's a lot more dynamic (with louder & quieter parts). I'm not saying it's bad if that's what you want. A lot of modern music is produced like this. (See The Loudness War.)

Some background - Most audio formats (as well as your digital-to-analog converters) are limited to 0dB (=1.0 =100%). However, Audacity (like most audio editors) uses floating-point internally, so it can "temporarily" go over 0dB. That means if you just boost the bass, you might not hear the clipping/limiting unless you have the playback volume set to 100%, or until after you save the file as a normal 16-bit or 24-bit WAV.

After boosting the bass, try the Hard Limiter effect set to 0dB. If that sounds too harsh or distorted, you can try the Compressor effect. There are several settings to experiment with, but normally a compressor (and/or limiter) is used to boost the overall volume without clipping/distorting the peaks. I believe Audacity's Hard Limiter effect is really a hard-clipping effect so you may want to look for a better limiter plug-in that can "round over" the peaks without as much distortion... I think that's what you really need... A good limiter applied after boosting the bass.

You might also try using a high-pass filter to remove the really deep bass (below 40 or 50 Hz). If you don't have a big amplifier and big woofer/subwoofer, any deep bass that your system can't reproduce just creates distortion. And just for reference, the lowest note on a normally-tuned bass guitar is around 40Hz, and big subwoofers used for dance clubs & live performances usually "only" go down to around 40Hz... That's deep enough for a good thump you can feel! (If you have the appropriate woofer & amp.)


You probably cannot achieve the "Lil Wayne" sound, but you may be able to get close to it. It has to start with the instruments & music on the recording... If another recording has different bass frequency & tone to start with, there is only so much you can do. The recording engineer can also process the bass guitar & kick drum separately before mixing with the vocals & other instruments... You can't do that. And, the recording engineer & producer has access to high-end plug-ins & tools and the skill & experience to get the desired sound out of it.

I'm really just looking for a clean way to boost bass that won't blow my speakers...

I can't guarantee that you won't blow your speakers! If you start boosting & compressing/limiting the bass, you are increasing the average power to your woofers, so if your amp is capable of blowing your speakers, it could happen.

I listened to LiL Wayne's Crazy official YouTube video and see it applies a resonator type bass frequency. If you haven't already found the following YouTube tut linked below on how to increase such bass frequencies follow the instructions to the letter and take note of how he chooses the Audacity Amplifier and Plot Spectrum to apply the right amount of EQ which he applies twice...

https://www.youtube.com/watch?v=yTEw8P_85Sg

And just for grins take a look at the marvels of subwoofers and digital processing in this guy's videos...

https://www.youtube.com/channel/UCjMmlD ... C862OrKm5Q

He also has an Audacity bass boost technique only it's for far much lower frequencies (10hz, 20hz, etc.) than Lil Wayne's 40Hz bass resonator.

https://www.youtube.com/watch?v=04aEttQh488

It's not clean bass. I did a quick analysis of the front of the song and yes it has beats at 50, but also at 150 and 300 (attached). It's "dirty bass" and they probably cooked it up in the studio. If you just boosted everything in that range it would get boomy and hurt your ears. If you made bass notes at 50Hz, it would sound too mushy and could create speaker damage.

No easy answer, sorry.

Koz

Any engineers/audio experts here ever heard about the waveform RMS (light blue middle section in Audacity waveform) having to stay within the RMS max specs of amp and speaker output?

I've heard this mentioned in other audio forums where the poster (didn't know if he was an expert) said clipping isn't the most important to be concerned about when playing loud frequencies. It seems to explain why I have some loud bass punchy music in aiff files I purchased on commercial, factory pressed CD's that shows clipping in Audacity but does not distort on my car audio speakers.

Does it actually show clipping, or does it show really dense waves up at 0dB?

Koz

kozikowski wrote:Does it actually show clipping, or does it show really dense waves up at 0dB?

Koz

See the screengrab below of the Audacity clip warning indicator on Theivery Corporation's "Rereturn Of The Original Artform-by Major Force" single off their "Outernational Sound" CD album.

https://www.youtube.com/watch?v=kG3_CduzbdU
Even the RMS is pretty thin but that boxy sounding bass beat sounds like some giant foot is in the trunk of my sedan trying to kick the back seat out. No distortions. It's a gorgeous sound that if I'ld played it at current loud volumes back in the '70's on backdash free air 6x9 Craig Road Rated speakers would surely have torn them to bits.

Also Flaming Lips' "It Overtakes Me" shows clipping with a huge RMS indicator waveform in its aiff off their "At War With The Mystics" CD which won a 2007 Grammy for Best Engineered Album. That bass line sounds incredible and loud off my back dash Polk 6x8's with a 80hz bass blocker. No distortion in that I don't hear electrical spark sound which will happen if I play it much louder.

https://www.youtube.com/watch?v=B4O7aI87E3g

And here's the Audacity Plot Spectrum sampled between 1:15-1:19min. of the Overtakes Me song.



It seems it should have a similar resonator sound as LiL Wayne's "Crazy" seeing 40Hz is at -8db but as you can hear from the YouTube video it doesn't. I guess music must be heard and edited taking into account the spectrum relationship instead of focusing on just one part of the spectrum.

Tim Lookingbill wrote:Any engineers/audio experts here ever heard about the waveform RMS (light blue middle section in Audacity waveform) having to stay within the RMS max specs of amp and speaker output?

The signal level, whether "peak" level, "root mean square" ("rms" / "RMS") or any other measure of signal level, has no relation to the specification of speaker output. Any (non-silent) signal can blow a speaker if amplified sufficiently. There is no "direct" relationship between signal level and loudness - put simply, turn the volume up and any non-silent signal becomes louder.

Digital audio signals are just a series of numbers. For "CD audio standard" (Redbook standard), the numbers are 16 bit signed integers (whole numbers between -32768 and +32767), and there are 44100 numbers per second for each channel (one stream of numbers for the left channel and one stream of numbers for the right channel). These numbers are converted to voltage by the digital-to-analog converter (DAC) which is then amplified to a high current signal by the amplifier. The "numbers" (the digital signal) cannot by itself blow amplifiers or speakers. Too much voltage from the DAC into the amplifier input will blow the amplifier. Too much voltage from the amplifier will blow the speakers.

Audio systems are often designed with amplifiers that are powerful enough to blow the speakers, so that the speakers can be driven close to their maximum rating with a "clean" (low distortion) signal. For such systems, it is the users responsibility to adjust the volume control to a sensible level to avoid damage to speakers.

"Clipped" signals (where the tops/bottoms of the waveform are cut off because they hit the maximum possible level) create high harmonics. It is common for excessive amounts of high harmonics to blow tweeters (high frequency drivers). Clipping distortion not only sounds "bad", but can damage audio equipment - including ears!