...without affecting the sound of the drums.
Requirements:
1.) The Amazing Slow Downer ($49.95) or any high quality software application that changes pitch, and
2.) Audacity (free). You may also use a Digital Audio Workstation (D.A.W.) i.e. ProTools, Cubase, etc.
In this explanation, The Amazing Slow Downer will be used to create a mono .wav file of just the bass (in your preferred key) and Audacity will be used to mix that mono bass file with the unaffected drum track.
After purchasing and installing The Amazing Slow Downer from http://www.ronimusic.com/ choose “Options” then “Preferences” with the following settings:
Sample Rate: 44100 Hz
Play Buffer Size: (start at) 4096 Samples (you may have to adjust this later based on the processing power of your computer)
Read Buffer Size: Big
Slow Down Quality: 3 (even though you are not “slowing down” the track, use this setting)
Checkbox for “Pitch Change affects speed”: leave unchecked
Click “Okay”.
To transpose the bass (only) from a DrumAndBassTracks.com file:
1. Use the “Mix” slider to pan the bass all the way to the right. This way, only the bass will be processed as it is mixed to the right side in the stereo field.
2. Left click “File” – then “Open File” and choose the backing track you would like to transpose.
3. Use the “Pitch” slider to change the key in semitones (half steps). See bottom of window for amount, i.e -2, -3). Semi-tones refers to half-steps (i.e.A to Ab), not full steps (i.e. A to B)
4. Use the “Play” button to make sure you are only hearing the bass. Click Stop or the "Save Song As" choice will not work.
5. Make any EQ adjustments necessary before exporting. If you are changing the pitch to a much lower key you will want to bring down the low end and bring up the high end. If changing to a much higher key, you will want to do the opposite.
6. Go to “File” – choose “Save Song As” - and choose “Wave File”
7. Make sure to set the following parameters: Repetitions – “1”; Audio Type – choose “Processed mono”. Then click “Okay”.
8. The “Save Song As Wave File” box will then open. You may wish to rename the file to the new key you are transposing it to i.e. “Any Song – mono Bass in (F)”.
9. Then click “Save” and wait for it to process.
10. You have now created a mono bass file in your desired key.
To create a Left/Right Drum and Bass file with the newly transposed bass track using Audacity:
1. Open Audacity
2. Go to “File” and “Open” the stereo backing track .mp3 that you wish to have in your desired key.
3. Go to “Project” then “Import Audio” and import the new bass track .wav file that you just transposed.
4. Pan the stereo track to the far LEFT (to isolate the drums) and pan the mono bass track to the far RIGHT (to isolate the bass).
5. Make sure that the new transposed bass .wav file aligns with the bass side of the original .mp3. If not, make the necessary adjustments.
6. Listen and make sure everything is correct.
7. Export as a stereo file in your file type choice (most likely and .mp3). Rename this file with the new key you have transposed it to i.e. “Any Song" key of (F).mp3
When transposing the bass to your desired key, always take the shorter distance to avoid "mud" (transposing down too far) - let your ears be your guide. Know that sometimes a bass track that was played in the upper register can be transposed down as much as 6-7 half steps and still sound natural, and visa versa going up.
NOTE: Using only one of the above programs for this whole process will not return the best results as transposing the bass needs to be a separate process so as to not affect the drums.