Power Requirements
The idle current of a CFSound-IV unit, no expansion modules with a 4GB SanDisk SD card installed is
~80mA @ 12VDC input.
With a background sound playing at a moderate level, the current consumption averages ~200mA @
12VDC.
Digital Audio Recording
Initially make all recordings (either music or voice) with a sample rate of at least 44.1KHz and 16-bit
mono or stereo. This high quality, first-generation recording will later provide the greatest bandwidth and
produce the best sounding final audio.
Recommended Recording Procedure
1.
Record any audio clip of your choosing @ 44KHz, 16-bit, Mono or Stereo. Make sure that your samples
do not clip (go above or below the sample window). The peaks of your audio clip, should, however, fill
vertically at least 95% of the sample window. If they do not, you will need to boost your input signal by
using a pre-amp or by some other means.
2.
Edit the clip until satisfied. You can use a sound editor or filter program, such as Syntrillium’s Cool Edit
to normalize the amplitude of the sample. Use this command cautiously though, since it also tends to
amplify noise levels. It is always preferable to re-record your sound clip at a higher level to achieve
better fidelity.
It is imperative that all initial editing and filtering be done to the audio clip while it is formatted at 16- bit
stereo and 44.1KHz. Please be certain that your recording environment is absolutely quiet. Recordings at 8-
bit or other sample rates can be played as-is or up-converted using suitable software.
Also remember that digital play-out devices do not introduce any static of their own other than
quantization noise. They only play back exactly what was recorded. If there is excessive static in the audio
clip or sample, then there was probably static in it originally.
Please see the videos on the
SUPPORT
page of the
CFSOUND.COM
website for additional information.
Self-Recording Procedure
The CFSound-IV has the ability to self-record audio presented at the line-level inputs into a contact
associated .WAV file on the SD card. This requires a freshly formatted relatively fast SD card to operate
properly – slow or fragmented SD cards may cause glitches in the recordings.
1.
Connect your audio source to the CFSound line-level inputs. The audio level must be adjusted externally
to avoid low volume and/or clipping in the recording.
2.
Press and hold both CFSound volume up/down buttons. After about half a second the Green and Red
LEDs underneath the SD card should begin toggling back and forth indicating that the recording process
is Armed. Once the LEDs start toggling, the volume buttons may be released. On a freshly formatted SD
card, the buttons would need to be held during Reset/Power Up to prevent Basic from starting since there
are no contact named .WAV files on the card.
3.
Now close and hold the contact that the recording is to be associated with. The Red LED should stay on
solid while the Green LED continues to blink - indicating that the CFSound is recording. When the
