APPENDIX A:
Input Sensitivity Level Setting
Following the directions below will allow the installer to adjust the input sensitivity of each amplifier channel pair simply and easily in just a few minutes using equipment which is commonly available in installation bays.
Necessary Equipment
•Digital AC Voltmeter
•CD with a sine-wave test tone recorded at
0 dB reference level in the frequency range to be amplified for that set of channels
(50 Hz for subwoofer channels, 1 kHz for a midrange application). Do not use attenuated test tones (-10 dB, -20 dB, etc.).
The Nine-Step Procedure
1)Disconnect the speaker(s) from the amplifier’s speaker output connectors.
2)Turn off all processing (bass/treble, loudness, EQ, etc.) on the source unit, processors (if used) and amplifier. Set fader control to center position and subwoofer level control to 3/4 of maximum (if used to feed the A6450).
3)Switch the “Input Voltage” switch to “Low” and turn the “Input Sens.” control all the way down.
4)Set the source unit volume to 3/4 of full volume. This will allow for reasonable gain overlap with moderate clipping at full volume.
5)Using the chart on this page, determine the target voltage for input sensitivity adjustment according to the nominal impedance of the speaker system connected to the amplifier outputs.
6)Verify that you have disconnected the speakers before proceeding. Play a track with an appropriate sine wave (within the frequency range to be amplified by the A6450) at 3/4 source unit volume.
7)Connect the AC voltmeter to the speaker output connectors of the amplifier. If the channel pair is operating in stereo, it is only necessary to measure one channel. If bridged, make sure you test the voltage at the correct connectors (L+ and R–).
8)Increase the “Input Sens.” control until the target voltage is observed with the voltmeter.
9)Once you have adjusted the A6450 to its maximum low-distortion output level, reconnect the speaker(s). The “Input Sens.” controls can now be adjusted downward if the amplifier requires attenuation to achieve the desired system balance.
Do not increase any “Input Sens.” setting for any amplifier channel or channel pair in the system beyond the maximum level established during this procedure. Doing so will result in audible distortion and possible speaker damage.
It will be necessary to re-adjust the “Input Sens.” for the affected channels if any equalizer boost is activated after setting the “Input Sens.” with this procedure. This applies to any EQ boost circuit, including source unit tone controls or EQ circuits. EQ cuts will not require re-adjustment.
Nom. | Target AC Voltage |
Impedance | Stereo | Bridged |
|
| | |
8Ω | 13.4 V | 26.8 V |
6Ω | 13.4 V | 25.6 V |
4Ω | 13.4 V | 24.6 V |
3Ω | 12.8 V | not recommended |
2Ω | 12.3 V | not recommended |
| | |
APPENDIX B:
Precise Frequency Selection Chart
“FILTER FREQ” AMP FILTER
Detent Panel Actual
Number Marking Freq.
Full counter-clockwise: 53
01 . . . . . . . . . . . . . . . . . . . . . . . . . . . .53 02 . . . . . . . . . . . “50” . . . . . . . . . . . .53 03 . . . . . . . . . . . . . . . . . . . . . . . . . . . .53 04 . . . . . . . . . . . . . . . . . . . . . . . . . . . .54 05 . . . . . . . . . . . . . . . . . . . . . . . . . . . .54 06 . . . . . . . . . . . . . . . . . . . . . . . . . . . .55 07 . . . . . . . . . . . . . . . . . . . . . . . . . . . .55 08 . . . . . . . . . . . “55” . . . . . . . . . . . .56 09 . . . . . . . . . . . . . . . . . . . . . . . . . . . .56 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . .57 11 . . . . . . . . . . . . . . . . . . . . . . . . . . . .58 12 . . . . . . . . . . . . . . . . . . . . . . . . . . . .59 13 . . . . . . . . . . . . . . . . . . . . . . . . . . . .62 14 . . . . . . . . . . . “60” . . . . . . . . . . . .65 15 . . . . . . . . . . . . . . . . . . . . . . . . . . . .65 16 . . . . . . . . . . . . . . . . . . . . . . . . . . . .66 17 . . . . . . . . . . . . . . . . . . . . . . . . . . . .70 18 . . . . . . . . . . . . . . . . . . . . . . . . . . . .73 19 . . . . . . . . . . . . . . . . . . . . . . . . . . . .77 20 . . . . . . . . . . . “80” . . . . . . . . . . . .81 21 . . . . . . . . . . . . . . . . . . . . . . . . . . . .84 22 . . . . . . . . . . . . . . . . . . . . . . . . . . . .88 23 . . . . . . . . . . . . . . . . . . . . . . . . . . . .94 24 . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 25 . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 26 . . . . . . . . . . “120” . . . . . . . . . . 115 27 . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 28 . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 29 . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 30 . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 31 . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 32 . . . . . . . . . . “150” . . . . . . . . . . 177 33 . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 34 . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 35 . . . . . . . . . . . . . . . . . . . . . . . . . . . 209 36 . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 37 . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 38 . . . . . . . . . . “200” . . . . . . . . . . 218 39 . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Full-clockwise: 225
APPENDIX C:
A6450 Specifications
General Specifications:
Recommended Fuse Value: 60A
Recommended Fuse Type: AFS, AGU or MaxiFuse™
Input Sections:
No. of Inputs: Three Stereo Pairs
Input Type: Differential-balanced with RCA jack inputs
Input Range: Switchable from 200mV - 2V RMS to 800mV - 8V RMS
Amplifier Section:
Amplifier Topology: Class A/B with patented Absolute Symmetry™ dual N-Channel MOSFET output design Power Supply: Unregulated MOSFET switching type Rated Power at 12.5 V (Stereo, all channels driven): 45W RMS x 6 @ 4 ohms, 75W RMS x 6 @ 2 ohms Rated Power at 12.5 V (Bridged, all channels driven): 90W RMS x 3 @ 8 ohms, 150W RMS x 3 @ 4 ohms THD at Rated Power:
<0.08% @ 4 ohms per ch. (20 Hz - 20 kHz)
Signal to Noise Ratio: >104 dB referred to rated power (A-weighted, 20 Hz-20 kHz noise bandwidth) Frequency Response: 10 Hz - 25 kHz (+0, -1dB) Damping Factor: >200 @ 4 ohms per ch./50 Hz, >100 @ 2 ohm per ch. /50 Hz
Slew Rate: ± 22V/μs
Power output at 14.4V supply voltage and 1% THD: 70W RMS x 6 @ 4 ohms (14.4V, 1% THD)
110W RMS x 6 @ 2 ohms (14.4V, 1% THD) Rated Power (Bridged):
140W RMS x 3 @ 8 ohms (14.4V, 1% THD)
220W RMS x 3 @ 4 ohms (14.4V, 1% THD)
Amplifier Filter:
Filter Type: State-variable, 12dB/octave Butterworth with continuously variable cutoff frequency selection from 50-200 Hz.
Configurable as Low-Pass or High-Pass. Defeatable.
Dimensions(LxWxH):
13.8" x 9.25" x 2.50" (350mm x 235mm x 63.5mm)
Due to ongoing product development, all specifications are subject to change without notice.
