Allows a signal to be played through your speakers or other audio device
To set the Audio sampling rate, click the drop-down menu to see popular rates. Note: not all sampling rates will be supported by your hardware. For typical applications, this should be set to 48kHz.
Leave the device name blank to choose the default audio device. Selecting a specific device name depends on the OS.
On OSX, go into the System Preferences, click on "Sound", and then the "Output" tab. The listings under "Name" contain the exact device names currently available; if a new audio sink is attached to the computer then a new name will appear -- for example "Headphones" for some Macs. Since most such device names contain spaces, make sure to put quotes around the name argument, for example:
spectrum_inversion.py -O "MacBook Pro Speakers"
On Linux, typical choices include:
For ALSA users with audio trouble, follow this procedure:
- from a terminal window enter:
- find the entry such as:
hw:CARD=Device,DEV=0 USB Audio Device, USB Audio Direct hardware device without any conversions
from the list which matches your device.
- use the first line of that entry (e.g. "hw:CARD=Device,DEV=0") as the device name (without the quotes).
- For issues or debugging see https://wiki.gnuradio.org/index.php/ALSAPulseAudio
OK to Block
On by default, which should be used when this sink is not throttled by any other block.
The audio sink can have multiple inputs depending upon your hardware. For example, set the inputs to 2 for stereo or 1 for mono.
This flowgraph should play a 1 kHz tone out of your speakers. Note that you don't need a throttle block, the Audio Sink should throttle for you. If you do end up using an already-throttled signal source, then set "OK to Block" to No.