Rebounder 1.0 ------------- by Grekim Jennings Rebounder is an audio delay/echo program designed to help in the task of finding good sounds in the studio by perfecting microphone placement. With excellent microphone placement you will need less equalization later when mixing. Naturally, the program can be used for other purposes that require a delay. The idea is that the solo audio engineer can be in the room with the microphones, and hear an echo of a recorded sound returned through headphones. Then the microphone can be adjusted and the sound re-evaluated. This avoids having to adjust the mic and go back to the control room to listen. It also allows the sound through the mic to be heard without the actual sound source itself bleeding into the headphones. While headphones may or may not be as good as monitor speakers for making such decisions, they can certainly be used in getting the placement relatively close, and a final analysis can done with monitors. Note that the actual delay time will be slightly greater than what you select since the Alsa buffer and the passage in and out of the soundcard itself is not accounted for. The amount of RAM used is dependent on the delay time set. The delay can be set to a maximum of 600 seconds (10 minutes) as long as your system will allow that much RAM (possibly 550-1100 MB, samplerate depending) to be used. WARNING: The input source (microphone) should not be near the sound output since a possible feedback loop could result. The output is generally intended for headphones and not an open speaker. Modes of Operation: ------------------- Mode 1: One mono input is mapped to one mono output. For example, you might have a bass drum hooked up to channel 8 of your soundcard. The echo can be sent to output channel 3. Mode 2: One stereo input is mapped to one stereo output. The input channel you choose indicates the first of the input pairs. So, if you choose 3 as your input, channel 4 will automatically be selected as an input. Output channels work the same way. Mode 3: One mono input is mapped to one stereo output. As in mode 2, the output channel choosen indicates the first of the pair. Command Line Arguments: ----------------------- The program is run from the command terminal and at least one argument, the soundcard device must be entered. You can also specify input source, output destination, time delay, sample rate, and timeout. The timeout time is how long the program will run before it stops. You can always ctrl-C to break the loop earlier than its timeout setting. The command arguments must be enetered in the following order: The default settings: --------------------- mode = 1 input channel = 1 output channel = 1 delay time (second) = 3.0 samplerate (samples/sec) = 44100 timeout (seconds) = 300 Example 1: rebounder plughw:0,0 1 8 3 6 48000 120 argument 1 is the soundcard device name = plughw:0,0 argument 2 is the mode = 1 argument 3 is the input channel = 8 argument 4 is the output channel = 3 argument 5 is the delay time = 6 sec argument 6 is the samplerate = 48000 argument 7 is the timeout time = 120 sec So, channel 8's input signal will appear in channel 3's output 6 seconds later. The program will stop running after 120 seconds. Because we are using mode 1, a signal will only be coming out of channel 3. Example 2: rebounder plughw:0,0 argument 1 is the soundcard device name = plughw:0,0 All other arguments will use the default settings as mentioned above. If you run the program without arguments you will get a basic reference text.