This week I created a interface class for PortAudio (cross-platform audio device handling library). It’s easy to use, just reimplement the abstract callback function, select how many channels, sample frequency and which device you wanna use. Based on this class I created the first version of my PortAudioSource for adsp.xconvolver. I also extended the room correction dialog (see the following screenshot) with spin controls to select the sample frequency and the audio device.
This weekend I managed to get my prototype working and I did the first measurements, which were saved in wave files:
- measurement_chirp_10-20000Hz.wav (original signal)
- loopback.wav (soundcard output directly connected to soundcard input)
- speaker.wav (nearfield measurement)
Original signal in time- and frequency domain:
Loopback signal in time- and frequency domain:
You can see that high frequencies are damped by the soundcards analog digital converter. 😛
Nearfield measurement in time- and frequency domain:
I know it’s a cery cheap speaker and frequency response is very bad, but that’s my speaker system for development. 😉
Here are some photos from my measurement equipment:
If all is stable and working I will repeat the measurement with my Denon X2000 and Teufel 5.1 speaker system.