Audio Recording

This is a tutorial on how to convert a midi file into a high quality WAV file. This will be using Adobe Audition 1.5. This tutorial is very helpful for the following scenarios:

a.) You find it hard to find reputable software for converting a midi to wav.
b.) You are working with synthesizers or other MIDI devices which will output only as MIDI but you need to export as WAV to Adobe Audition multi-track or edit view for further processing.
c.) You are not happy with the quality of the MIDI and you would like to make a high quality version out of that.

Let’s have an example. Supposing you need a public domain recording of a classical piano music; however most sound recording released (in WAV and MP3) are not still in public domain so you cannot use those recordings without paying a license fee and asking permission from the recording label. The only thing you can obtain a free version of that classical piece is to use the MIDI version of the music. However MIDI version does not sound good as the original recording. This tutorial can help you improve the quality of the piano MIDI version of any classical piece. Supposing I would like to create a WAV version of the Moonlight Sonata First movement MIDI by Beethoven; I employ the following steps:

Step1.) Search for free MIDI version of the music in Google. This is a sample result page from the search:
http://www.8notes.com/scores/1754.asp?ftype=midi

Step2. ) Download the MIDI file to your Desktop. Then play the MIDI using a Windows media player to make sure you are downloading the correct music.This is the sample MIDI. You can listen to it here. MIDI does not provide a quality recording of the music because it is digitally generated, if you listen to it you will noticed that:

a.) There is no ambiance or reverb in the music. It sounds relatively artificial. Real piano pieces are played on concert halls and will have some reverberations.
b.) The piano seems to be dull and digitized. Real piano sounds are full, with bass and highs.
c.) The volume is very low.

Step3.) Do not yet close your Windows media player with the midi file on it. Now launch Adobe Audition. In the Edit view; go to File — New. Select 96Khz as the sampling rate then “Stereo” for the channels and 32-bit float for resolution; see screenshot:

Click OK.

Step4.) Configure your Soundcard to record system sound. For example in Create Audigy soundcard, recording mode can be set to “What U Hear”, see screenshot:

Step4.) Hit Record button in Adobe Audition and then play the MIDI file in Windows media player. The output sound of the Windows media player will be captured by Adobe Audition. The audio wave will be generated, see screenshot:

As you might observe, the captured peaks of the wave are very small. It is due to the low volume nature of the original midi file. Let’s apply the following sound processing effects to make it sound better:

a.) Apply Parametric EQ ((Effects – Filters – Parametric EQ) :

Low shelf filter: +4dB 200Hz (adds bass to the piece, bass response is very lacking in MIDI)
+1dB 400 Hz Q=1.0 (wideband boost for low piano octave scale, this depends on the music)
-4dB 800Hz Q=1.4 (minimize the harshness in 1 KHz response common in MIDI)
+2dB 5000Hz Q=1.0 (add some high frequency response)
+2dB 10000Hz Q=1.0 (further adding some high freq.)

b.) Go to Effects – Delay Effects – Full Reverb – Medium Concert Hall (Crisp) Presets (see screenshot)

c.) Normalize the audio to make loud. Go to Effects – Amplitude – Amplify/fade – Click “Constant Amplification” tab then hit “calculate now”. Then click OK. The audio wave will be boosted.

d.) Apply sample rate conversion and dithering to convert it from 32-bit float/96Khz resolution to 16 bit/44.1Khz. You can then convert it to high quality MP3. This is the final output of the conversion process:

There is a big improvement in sound when the midi file will be converted to wav and then applied with the right sound processing effects to make it sound like a real piano. Take note that this tutorial works best for classical piano pieces (such as emulating the real piano sound). It won’t work very well for string pieces (such as violin and guitars).