Dynacord DMM 4650 Recording level, Remote recording, Audio quality, recording duration

Recording level

An integrated, electronic control automatically adjusts the input sensitivity of the DMM 4650’s (Mic, Line, Rec. Inp) inputs. This level setting remains unchanged, until the question “Select new recording level?” is answered by using the soft key “y=yes” before starting a new recording. By using a short test signal marks the new setting of the control which is automatically stored. Pressing the soft key “ok” exits the recording level menu.

Adjusting the recording level only becomes necessary when the connected signal source is changed or major level changes occur.

Remote recording

It is possible to activate a recording via one of the control inputs (ports A .. D). An example given in the list of factory sequences (S29, S30) on the pages 40-41. The message defined within the sequence is automatically erased before the new recording starts. The example employs an indication lamp for start recording (= deleting end) and the maximum recording time is set to 10 seconds.

Adjusting the recording level corresponds to the description in the previous paragraph. The message’s audio quality setting stays unaltered as well. The priority number of the sequence gets copied to the priority of the message.

Audio quality, recording duration

Prior to recording a message, “recording type” is shown on the display. The cursor keys are used to alter the audio cutoff frequency (16 kHz, 8 kHz, 4 kHz) and the signal quality (CD = 16 bit linear, long = 8 bit, µ-Law). The factory default setting is “8 kHz long” for all messages. The newly set audio quality is maintained and individual adjustment for each message is possible.

Table for recording time (minutes) versus audio quality and installed sound memory extension (NR 90205).

Accuracy	CD			long*
bandwidth	4 kHz	8 kHz	16 kHz	4 kHz	8 kHz	16 kHz
without NR 90205	2 min	1min	0,5 min	4 min	2 min	1 min
1x NR 90205	4 min	2 min	1 min	8 min	4 min	2 min
2x NR 90205	6 min	3 min	1,5 min	12 min	6 min	3 min
3x NR 90205	8 min	4 min	2 min	16 min	8 min	4 min

*The specified times for the"long" recording mode are minimum values since the active data reduction recognizes pauses in the audio signal. Pauses are defined as passages where the signal level drops -70 dBu below full modulation.

Message memory extension

It is possible to extend the sound memory capacity of the appliance by incorporating up to three additional plug-in boards (extension kit NR 90205). The corresponding recording times are specified in the table above. The flash memories have to be formatted after insertion (see menu “system setup” > “format flash”).

Asterisk (*) behind message duration

An asterisk * behind the message recording time display signals that the corresponding data has been corupted. The error is shown by the blinking Power-LED. In case you decide that the audio quality is sufficient, after listening to the recording, you have to enter the menu “confirming” (page13) to delete the *-sign. If the result is not tolerable, the only solution is re-recording the message. To omit the blinking Power-LED you have to acknowledge error no. 14 in the “self-test” menu (page 29).

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