how to analyse the bass and the treble on a file mp3

Hi all
I want to know if its possible to analyse a file mp3 to see the level of bass and treble? when i use the effect on Audacity the open window show each file at 0. It means that i can adjust as i want but my problem is to understand what are the values of the original file and after i can decided what to adjust. Thanks for a reply. Ciao

“Plot Spectrum” shows the frequency content of the selected audio (up to about 10 million samples)

Your ears are usually the best way to do it… Of course, you need good-accurate speakers/monitors and a good room (or good headphones). Bass is particularly troublesome in “normal” rooms because you get [u]standing waves[/u] that create peaks & dips at different frequencies at different points in the room, and they depend on room dimensions & acoustics.

Pro mixing & mastering engineers typically use a known-good recording in the same genre as a reference to keep their “ears calibrated”. Without a reference it’s easy to get carried-away and over-do the equalization (or any other effects).

After making adjustments (especially if you boost anything) it’s a good idea to Amplify or Normalize before exporting the changed file. Otherwise, you may go over 0dB and [u]clip[/u] (distort). …Audacity itself can go over 0dB, but “normal” WAV files, CDs, and your digital-to-analog converter are all hard-limited to 0dB. Amplify and Normalize will can bring the levels up or down as needed. (When you “amplify” with a negative dB value you are actually attenuating rather than amplifying.)

And… That means if you boost the bass by a lot you’ll have to reduce the overall volume and the file will sound quieter… Especially if you boost the very-deep bass that’s hard to hear and hard to reproduce (unless you have a big amplifier and big woofer/subwoofer.)

I know of at least [u]one program[/u] that tries to automatically match the EQ of a file to match a reference. That one is not free. but there may be something similar that’s free (or cheap).

to analyse a file mp3

As you may know, MP3 is lossy compression. It’s not “bad” and a good-quality (high bitrate) MP3 can often sound identical to the uncompressed original. But when you open an MP3 in Audacity (or any other “regular” audio editor) it has to be decompressed. If you re-export to MP3 it goes through another generation of lossy compression and the “damage” DOES accumulate. Of course “analyzing” doesn’t hurt anything because you’re not changing anything and you don’t have to re-export the file.

It’s BEST to start with a lossless original and then compress ONCE as the last step if you want to use a lossy format. And if you don’t have a lossless original, try to minimize the number of times it’s re-compressed.

TDR Nova is a free* plugin which works in Audacity on Windows.
It’s a real-time equalizer & spectrum-analyzer.
You can immediately hear the consequence of adjusting the equalization settings,
and see the effect of equalization on the in/out (before/after) spectrum displays

[ * there is a luxury “Gentleman’s” version which costs ~$60 , but the free version is perfectly adequate ].

Currently only 32-bit plugins work in Audacity, even if your machine is 64-bit.