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Full Version: Shannon, - Sample rate Question..
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Hi,

I usually play ultrasonics from my laptop in win 7, and came across this info on the net. Can someone please tell me what sample rate we should be playing or subs at using the computer for playback ?


Settings are found in "Playback devices, Speakers, Speaker Properties, Advanced"



Playback audio format

On Windows Vista and Windows 7 you can select the audio format that is used by playback devices in the so called shared mode.
This determines the sound quality that is selected in the Sound Recorder for the What you hear on ... sound source and it may effect what you hear in the Editor when playing back recordings.
On this page we explain how you can determine which the right audio format to select is and at the end of this page we show you how to change or check the selected audio format in Windows.

Shared mode is used by most audio playback programs, which means that all those programs can connect to and playback to the same device simultaneously. Windows takes care of mixing all these audio streams into one single audio stream that is sent to the playback device. It does this in the selected audio format, thus sound quality.

So no matter which audio format or sound quality is being played back, if it is different than the selected audio format, it will be converted to the audio format that is selected for the playback device. This causes audible side-effects!

These side-effects will also be recorded when you record from the What you hear on ... sound source, because this records exactly what you hear, including the side-effects that are introduced with the conversion to the selected audio format.

On older Windows versions like Windows XP, this was done differently. In shared mode of XP, Windows would automatically pick the highest sound quality of all streams that were playing back. Why Microsoft decided to change this is a mystery to us, because this method is off course much better. If only one program is playing back, which is usually the case, then no mixing and also no conversion of the audio format was necessary and thus the original sound quality was preserved.

As opposed to using shared mode, programs can also access the sound card in exclusive mode. In exclusive mode the program will have full control over the audio format and thus the sound quality. The disadvantage will be that no other program (not even Windows itself) can playback any audio anymore, as long as this exclusive connection is active. This will be a problem if a Skype call comes in for example.
If the audio playback program you use has this exclusive mode option, you may consider to switch it on, to be ensured that you always hear your music at the correct and original sound quality. However, in that case you will not be able to record through the What you hear on ... sound source anymore, because the Sound Recorder can also not access the sound card anymore if a program accesses it in exclusive mode.
For various reasons, the PolderbitS Sound Recorder and Editor always uses shared mode.

So on Windows Vista and Windows 7 we have to deal with this single audio format that is used for shared mode and there are several possible reasons to change it, or at least to check what is currently selected on your computer:

Audio formats with a sample rate higher than 48000 Hz, or with a bit depth higher than 16-bit, are meant for professional use in studios for example.

If you don't have to deliver to, or work in the professional audio industry, then selecting sample rates higher than 48000 Hz, or bit depths higher than 16-bit, makes no sense at all and is a waste of processing power and memory.

If you want to record from the What you hear on ... sound source and the Sound Recorder says that the audio format is not supported, then select either 16-bit, 44100 Hz (CD Quality), or 16-bit, 48000 Hz (DVD Quality), whichever best matches what's playing back.

The Sound Recorder only works with 16-bit Audio and will convert 24- or 32-bit audio to 16-bit, which would be a waste of processing power and memory.

If you primarily play audio CD's on your computer, make sure that the selected audio format is 16-bit, 44100 Hz (CD Quality).

On most computers, DVD Quality is selected by default and converting CD Quality audio (as on Audio CD's) to DVD Quality introduces a slight ringing effect. This is clearly audible during relatively silent fragments.

Selecting a 24- or 32-bit quality is a waste of processing power and memory, because Audio CD's contain 16-bit audio.

Likewise, if you primarily play DVD's on your computer, make sure to select the 16-bit, 48000 Hz (DVD Quality) audio format.

If you primarily listen to on-line music or downloaded sound files, try to figure out which sound quality is most commonly used on those web sites or in those sound files and select that for the audio format.

If you open a wav or mp3 sound file in the Editor, it will tell you which sound quality it is at Recording quality.

If you primarily record at Compact Disc sound quality in the Sound Recorder, make sure that the selected audio format is also 16-bit, 44100 Hz (CD Quality).

The same applies to recording devices. When audio is being recorded with the Sound Recorder, it will always be recorded from the device with the audio format you selected for the recording device. This may have to be converted, if the sound quality you selected in the Recorder has a different sample rate.
The subliminals are recorded at 44.1 kHz. This is known as "CD quality". If you have the option, use 44.1 kHz.
Will do so. - Thx Shannon !