Bitrate doubles when exporting to WAV

I open a wav file in Audacity 2.2.2, Win 10 64bit. The file is Mono, 22050Hz, 32-bit float. Project Rate (Hz) is 22050. 1 (Mono) Recording. In the folder the file has the Bitrate 352 kbit/s. But if I export as wav the new file shows Bitrate 705 kbit/s and has doubled in size from 111 kB to 222 kB even if I make no changes with the file in Audacity. This has happened several times and yesterday I could stop it from happening when I changed from 2 (Stereo) Recording to 1 (Mono) Recording but today it suddenly started to double the bitrate again. The wav file is one of the four engine sound files used for generating a SoundRacer file and the generating SW cannot work whith the double Bitrate.

What is the sample rate and number of channels of the exported file? (this webpage can tell you: MediaInfoOnline - MediaInfo in your browser )

Also, just wondering why you are using 32-bit float. That seems like massive overkill considering your original files have a low sample rate (22050 Hz).

The file is Mono, 22050Hz, > 32-bit float. > Project Rate (Hz) is 22050.

By default, Audacity works internally at 32-bit floating point so what you see isn’t always what you start with or what you get. Usually you are not importing/exporting floating point.

For uncompressed files: Bitrate (kbps) = Sample Rate (kHz) x bit depth x number of channels.

22.050kHz x 16 bits x 1 channel = 353 kbps
22.050kHz x 16 bits x 2 channels = 706 kbps
22.050kHz x 32 bits x 1 channel = 706 kbps

FYI - As you can see, we can calculate the bitrate for uncompressed files but when we’re working with uncompressed files we usually we don’t talk about bitrate… Usually we talk about the sample rate, bit depth, and number of channels… Normally we only talk about bitrate for compressed files.

If your system requires a certain format you probably need all of those details “match”. It’s probably not enough to know the bitrate. The same goes for compressed formats… The bitrate and compression format may not be enough information.

The file spec was decided by the sound engineer (Greg Hill, Australia) that supplied the original engine sound files for SoundRacer: idle is 11025 Hz, 176 kbit/s, onlow, onhigh (acceleration sounds) and offlow (deceleration sound) are 22050Hz, 352 kbit/s, all are mono and shows as 32-bit float when opened in Audacity.
But I may have just found the problem, looking in Edit/Preferences/Quality/Default Sample Rate was 11025 in the 22050 Hz offlow file. When I changed to 22050 the exported wav was 352 kbit/s again! So it must be the same as original sample rate.

As DVDdoug wrote, that’s because Audacity automatically converts them to 32-bit float format.

11025 kHz, mono, 176 kbps = 16 bit
22050, mono, 352 kbps = 16 bit.

Thanks steve and DVDdoug for assistance, now I will start a new question about the problem that I tried to solve with Audacity