When inserting audio clips in Cakewalk Home Studio, you often need to know the original tempo of the clip in order to have the measure boundaries line up with the beats of your audio recording. This is particularly important when working with drum loops, but can also help you with your editing work. If you don’t have an application that can calculate the BPM (Beats Per Minute) of audio, there is a mathematical method you can use.
As an example, let’s use the file “Don’t Matter Audio and MIDI .cwp” Demo that comes with Home Studio 2004. Open that file, and you’ll see the tempo of the song is 113.86 BPM. Let’s see how we could have determined that tempo if we only had an audio clip to begin with.
Select the second clip in the Bass track, as it contains four beats (you can tell this by listening to it). Open the Event List for this clip and you’ll see the number of samples listed: 185923.
If the sample rate of the Home Studio project is 44.1kHz, as it is in Don’t Matter, we know that 44100 samples are played every second. We also know there are 60 seconds per minute. Finally, we know by listening that there are 4 beats in the audio selection.
Therefore, multiplying the number of samples per second (44100) by the number of seconds in a minute (60), and then multiplying that by the number of beats in the selection (4), gives us the basis number for our equation.
44100 x 60 x 4 = 10584000
We then need to divide that number by the number of samples in our selected audio loop.
10584000 / 185923 = 56.93.
This suggests the tempo (BPM) of the audio is 56.93. However, notice that the Tempo Ratio box in Home Studio’s tool bar is set to 2:1, meaning that the actual Metronome tempo is doubled.
56.93 x 2 = 113.86
We can now place that number in Home Studio’s Tempo field, and the measure boundaries will line up properly. You can now apply this technique to any audio clip you insert in Home Studio, filling in your numbers in the equation:
1058400 / (samples in the audio clip) = (tempo of the audio clip)
If your audio clip was recorded at 48kHz (you’ll see this listed in the Event List window as well), the basis number changes to 11520000. The rest of the equation stays the same.