Hello, my name is Rusty. I'm a sound engineer, let's take a look. The tempo information to an audio file will definitely keep the same tempo. To change the tempo of a .wav file, you have to decrease the bitrate, and it will naturally speed up.
The drums are built in, and can change the bit rate easily. I want you to record a new .wav file, only don't record the tempo information this time. Tell me if that works. Otherwise, we will have to change the sample rate to speed it up or slow it down. That's an extra step, and can be a little confusing if you're not used to working with samples.
Well, no, that's how .wav files work. Midi files are able to change their tempos, but .wav files are recordings, and will play as they were recorded. The bit rate is the speed in which they play, therefore the way to change the tempo of a .wav is to change the bit rate.
Click here, this is one way. The other way is to start a new session. Your current bit rate is at 44,100. If you make the new session a higher bit rate, it will slow down the wav. If you start it at a lower rate, it will speed the wave up.