Operation Manual
15
To obtain high-quality audio recording, we suggest you follow the guidelines below.
You are not recommended starting recording while the device is connected to PC USB port.
Otherwise, the recorder disconnects from PC and the recording process will be enabled. Because
of PC interference of 5 V, you may experience poor audio recording quality.
After the device memory is 50%-100% full, you are recommended formatting the device
memory instead of deleting recordings one by one in order to extend flash memory life
(see Section 9.3.5).
The best mic recording performance can be achieved with PCM 24 bit and 22050 Hz sampling rate. Stereo
recording with high sampling rate provides speech intelligibility and excellent audio quality even in noisy
environment.
Mono recording mode involves audio recording through only one internal or external mic input (left
channel).
To prevent data losses, use volume-triggered recording mode only if input signal level is stable and
predictable.
Place microphones as close to the signal (speech) source as possible (but not closer than 0.5 m) and as far
from the acoustic and electromagnetic noise sources as possible. The closer the microphones are placed to
the acoustic signal (speech) source, the smaller the reverberation (echo) will be and the higher gain level and
speech intelligibility will be achieved.
During stereo recording, external microphones must be placed at least 15 cm away from each other. Try to
place the microphones in such a way as to avoid vibration, and rubbing against other surfaces.
External microphones are more sensitive and at the same time can be easily concealed (under a jacket lapel,
shirt collar, on the cuff). At the same time, they are subject to external electromagnetic interferences.
Avoid permanent contact of the device or external microphones with rough surfaces (such as table, car body,
walls, etc.).
7.3.2
Manual Recording
Recording can be started/stopped both manually and automatically.
To start recording manually, move the
ON
/
OFF
slide switch (
3
in Figure
1) to the
REC
position (or the
remote control switch in the
ON
position). To stop recording, move back the
ON
/
OFF
switch to the
STOP
position or remote control to the
OFF
position.
The remote control replicates the positions of the
ON/OFF
slide switch (
3
in Figure
1). See the description in
the table below:
The remote control position
Position of the switch (
3
in Figure
1
)
Recording mode
ON
REC
Recording is on
ON
STOP
Recording is on
OFF
REC
Recording is on
OFF
STOP
Stopped
