> Nice. Is there a limit on the length of the wav file? And can you save th=
e heterodyned sounds? David could just mix it into his recording.
Hi Peter,
The SASLab software can open common .wav files of up to 2 GB in size and t=
he heterodyned playback has no limit on the length of the file. In order to=
accelerate opening large files I would recommend to activate the option "F=
ile"/"File Open Settings..." > "do not create a temporary copy (limited und=
o!)"
The Frequency Shift function on the Frequency Domain Transformation dialog=
box has however a limitation on the duration (it is intended only for proc=
essing a few calls at once) and it will only work on mono files (the softwa=
re has been designed primarily for bioacoustic research, which seldom requi=
res stereo).
There is no direct way to save the heterodyned sounds. But it could be don=
e as follows:
1. Launch the Dialog box "Edit"/"Change Volume..." and select the Option "=
Modulation freq." on the section "Amplitude Modulation / Multiply by".
2. Enter here the desired tuning (center) frequency, such as 40000 Hz for =
instance and click at Ok.
3. Low-pass filter the resulting amplitude-modulated waveform from "Edit"/=
"Filter"/"Time-Domain IIR Filter..." (use here the option "Low Pass" and en=
ter a cutoff frequency (fco) of about 10 to 20 kHz.
4. Save the modified file from "File"/"Save As..."
Bye the way, the software can also be easily configured for time-expanded =
playback. Just go to "File"/"Playback settings...", check the option "other=
sample rate" and select here a sample rate of for instance 11025 Hz. Don't=
forget to disable the heterodyned playback mode in case you tried it befor=
e.
Regards,
Raimund
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