7.1.1 Selecting the audio devices

It is possible to select which audio devices the editor uses as the recording and playback device using the ‘Setup Audiocard’ dialog. This is accessed via the ‘Audiocard’ setting in the ‘Option’ menu.

The BMS editor can use any wave sound device available to Windows. A list of all the available devices is shown in the dropdowns at the top of the dialog.

Notes

· Only audio devices available to Windows will be visible in the dropdowns. If no devices are showing, check your soundcard installation.

· It is possible to set the default devices which the editor uses on startup in the editor .ini file – See section 7.2 ‘Advanced Editor Set-Up’ for more information.

7.1.2 Changing the input and output sample rate

The sample rate both of the editor playback output, mix to file output and the record input can be freely varied. Due to the in-built sample rate conversion, there is no restriction on sample rates, and indeed files can be recorded with a different sample rate to that at which they are played back.

The sample rates for playback, recording and mix to file are set using the appropriate dropdowns in the dialog.

	Sample rate settings

Notes

· Not all soundcards will support all sample rates. Lower-end, domestic type soundcards rarely support 48KHz, for example. If a sample rate which is not supported by the card is selected, typically either no output will be heard, or playback will be at the wrong speed or distorted. Always check your soundcard’s capability before altering these settings.

· If your soundcard supports external referencing, and is referenced to a word clock or similar, ensure that the settings in the ‘Setup Audiocard’ match the reference used. Unexpected results could occur if they are set differently.

7.1.3 Setting the input and output word length

The word length of the audio input and output can also be varied using the ‘Setup Audiocard’ dialog (see section 7.1.1 for details on recalling the dialog).

Word lengths up to 24 bit are supported. If a smaller wordlength than the source material is selected (either on record or playback), the editor truncates at the required wordlength.

Notes

· Not all soundcards support wordlengths in excess of 16 bits. Care should be exercised before using these settings – one common symptom of attempting to address a 16 bit soundcard with a 24 bit audio stream is high level digital noise. Whilst not dangerous to the software or PC hardware, it can damage speakers and amplifiers.

7.1.4 Using monaural mode

The editor can be put into mono mode using the ‘Setup Audiocard’ dialog (see section 7.1.1 for details on recalling the dialog).

Selecting the ‘mono’ radio button under the ‘playback’ section (on the left) sums the right and left outputs from the editor. Selecting the ‘mono’ radio button under the ‘Mix to file’ section (in the centre) sums the right and left outputs during the mix to file process.

Selecting ‘stereo’ returns to normal stereo operation.

7.1.5 Altering the real time factor

The playback ‘real time factor’ can also be varied using the ‘Setup Audiocard’ dialog (see section 7.1.1 for details on recalling the dialog). This determines how the software addresses the soundcard, and is related to soundcard buffer size and bus speed.

This is the single most significant setting in determining the software performance and playback quality. In general, it should be set to the lowest value which gives a good result. For professional soundcards, a value of 40 is usually acceptable.

If poor audio performance is encountered (eg playback stuttering), the real time factor should be increased. Typically consumer soundcards need a value of around 180.

It should not be necessary to alter the ‘mix to file’ real time factor, as this has relatively little impact on editor performance. A value of 500 is usually fine. Sometimes, however, it may be advantageous to shorten it if the editor performance seems sluggish when performing editing simultaneously with mix to file.

If problems are encountered at all real-time factor levels, it may be necessary to alter other software parameters. See section 7.2 ‘Advanced Editor Set-Up’ for more information.