Nakamichi NBF25.0A User manual

NBF25.0A
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User Manual

A. POWER STATUS LED
This bi-color LED glows green when power is
on and no problems are present. If one of the
protection circuits comes on, it will change to
red.
B. PHASE SHIFT
Use this switch to help compensate for time
alignment problems in the system. Such
problems usually result from having the
subwoofer at a different distance from the
listener than the other speakers in the system.
C. AUTO POWER ON
The AUTO POWER ON(ON/OFF) is for high level
(speaker-level) connections. When the switch
is in the "ON" position, the subwoofer will AUTO
POWER ON when there is signal input.If the
amplifier detected no signal input, the
amplifier will auto turn off, If you prefer to use
the remote turn on/off connection, the switch
is in the OFF position.
Note: Please connect the remote terminal to
the remote output of head unit as Fig.4 when
you hear the unit turn ON/OFF POP noise from
the subwoofer.
D. LOW PASS FILTER
This control permits you define the frequency
range you want the subwoofer amplifier to
receive. The subwoofer will reproduce all
sound below the frequency you set.
Note: The low pass filter frequency can be
higher or lower than the standard. There have
+/-20% tolerance.
E. BASS BOOST
The BASS BOOST feature will increase the
sound level in the bass frequencies.
F. INPUT GAIN CONTROL
After you have installed your system, turn this
control to minimum.
Turn the head unit on (and the subwoofer will
turn on via the remote connection). Turn the
head unit volume to about 2/3 full level.
Slowly turn up the subwoofer input gain
control until you hear a small amount of
distortion. Then reduce the level until the
distortion is completely gone. Level the
control at this setting.
G. REMOTE LEVEL CONTROL PORT
Attach the included remote level control to
control the volume level of the subwooer
independently.
H. HIGH LEVEL (SPEAKER LEVEL) INPUTS
If your head unit does not have RCA outputs
you can use the speaker outputs for the audio
source for the subwoofer. Use the supplied
cable and wire harness and connect the
outputs properly as shown in the connection
diagram in this manual.
I. LOW LEVEL RCA INPUTS
Low level inputs are the recommended way
to introduce the audio signal to the subwoof-
er if RCA outputs are present on your head
unit or other signal source (such as a sound
processor).
J. FUSE
Do not use a fuse with a different value and
never replace the fuse with a wire or coin.
K.POWER INPUT TERMINAL
PANEL CONTROLS AND FEATURES
1EN

2EN
WIRING
HIGH LEVEL INPUT WIRING
The high level input(s) should only be used when your receiver lacks RCA outputs. If the RCA
outputs are not present, connect the speaker outputs from the receiver to the high level input
connector of the amplifier. Be sure to observe polarity to avoid audio phase problems.
LOW LEVEL INPUT WIRING
Low-level (RCA) input wiring is preferred for best audio performance. Most trunk and under-seat
installations will require a 6-12 feet RCA cable. Always use a high quality cable.
POWER CONNECTIONS
Connect the ground terminal to the closest point on the chassis of the vehicle. Use 8 gauge (or
heavier) wire to connect the ground cable.
Connect the remote terminal to the remote output of head unit using 16 gauge ( or heavier )
wire.
Connect an empty fuse holder within 16" (40 cm) of the car battery, and run 8 gauge (or heavier)
cable from this fuse to the amplifier location. Then connect the fuse holder to the "BATT+" (+12V)
connection on the subwoofer rear panel.
NOTE: Do not connect BOTH the high level and low level inputs from your receiver to your amplifier
at the same time!
NOTE: Do not connect BOTH the high level and low level inputs from your receiver to your amplifier
at the same time!
Fig.1
Fig.2

WIRING
REMOTE LEVEL CONTROL CONNECTION
Fig.3
Fig.4
Fig.5
3EN

ACCESSORY LIST
1. User Manual
2. Mounting Screw Bag (Ø4x25mm x 4pcs, Ø3x14mm x 2pcs, Ø4x6mm x 8pcs)
3. Input Cable
4. Remote Control
5. Remote Cable
6. Mounting Bracket
1pc
1pc
1pc
1pc
1pc
4pcs
SPECIFICATIONS
150W
1000W
<0.5%
>90dB
20Hz - 180Hz
1.0V
300mV
N-power
Max power
THD
Signal-to-noise ratio
Frequency response
Input sensitivity,high level
Input sensitivity,low level
Low pass filter
Bass Boost
Subsonic Fiter
Fuse rating
Subwoofer
Dimensions (L x W x H) mm
50Hz - 180Hz
0 - 12dB
20Hz (Fixed)
25A
10" , 4 Ω
300 x 225 x 72mm
4EN

5EN
TROUBLESHOOTING
If you experience operation or performance problems with this product, compare your installation
with the electrical wiring diagram on the previous pages. If problems persist,read the following
troubleshooting tips which may help eliminate the problems.
SYMPTOM
Products will not
power up
Check to make sure you have a good ground connection.
Check that the Remote Input (Turn-on) has at least 5V DC.
Check that there is battery power on the (+) terminal.
Check that there is at least 12V.
Check all fuse, replace if necessary.
Make sure that the Protection LED is not illuminated. If it is lit shut off the
amplifier briefly, and then repower it.
Protection LED comes
on when amplifier is
powered up
Turn down the volume control on the head unit to prevent overdriving.
Check that there is good air cirulation around the amp.
No output
Check that all fuses are OK.
Check that unit is properly grounded,
Check that the Remote Input (Turn-on) has at least 5V DC.
Check that the RCA audio cables are plugged into the proper inputs.
Low output Reset the Level Control.
Check the Crossover Control settings.
High hiss in the sound.
Disconnect all RCA inputs to the power sub's control panel. If the hiss
disappears, then plug in the component driving the amplifier and unplug
its inputs. If the hiss disappears at this point, go on until the faulty/noisy
component is found.
lt is best to set the amplifie's input level control as low as possible. The
best subjective signal-to-noise ratio is achieved in this manner. Try to set
the head unit as high as possible (without distortion).
Squealing noise is
present. Check for improperly grounded RCA interconnects.
Distorted sound. Check that the lnput Level Control is set to match the signal level of the
head unit.
POSSIBLE REMEDY
Engine noise
(static type)
This is usually caused by poor quality RCA cables, which can pick up
radiated noise. Use only the best quality cables, and route them away
from power cables.
Engine noise
(alternator whine)
Check that the RCA grounds are not shorted to the vehicle chassis.
Check that the head unit is properly grounded.

6CN
低電平輸入連接方式 高電平輸入連接方式
遠程電平控制連接
面板控件和功能
電源輸入連接方式
方式一：
E.低音提升電位器
F.音量電位器
G.遠程低音音量控制端口
H.高電平輸入端口
I.低電平輸入端口
J.保險絲插座
K.電源輸入端子
A.電源狀態指示燈
B.相位轉換開關
C.自動開關機控制開關
D.低通濾波器電位器
Fig.1 Fig.2
方式二：
Fig.3
Fig.5
Fig.4
注意：開關主機時，如果聽到有開關機衝擊聲，
此時自動開關機開關要設定在“OFF”位置。改用
主機的REMOTE線來控制開關機。
注意：低通濾波器的實際頻率有可能高于或低于
設定值，誤差在±20%左右
注意：高電平和低電平不要同時輸入！

150W
1000W
<0.5%
>90dB
20Hz - 180Hz
1.0V
300mV
50Hz - 180Hz
0 - 12dB
20Hz (Fixed)
25 A
10" , 4 Ω
300x 225 x 72mm
額定功率
最大功率
總諧波失真
信噪比
頻率響應
高電平輸入靈敏度
低電平輸入靈敏度
低通濾波器
低音提升
高通濾波器
保險絲額定值
主動低音喇叭，負載
尺寸（長x寬x高）
故障原因
1.調低音量電位器以防止過載保護。
2.檢查濾波器電位器大小是否合適。
1.重新設定音量電位器。
2.檢查濾波器電位器是否在正確的位置。
1.斷開功放的信號輸入線，如果嘶嘶聲消失就是信號源有問題，
此時要確認信號線是否連接良好，或信號線質量是否有問題，
否則主機可能有問題。
2.盡可能把功放音量電位器開小，同時盡可能把主機音量開大
（不要失真）。
1.檢查RCA的地線是否連接好。
1.檢查功放音量電位器是否过大了，功放音量電位器要配合好
主機音量。
2.檢查濾波器電位器大小是否合適。
1.主要是RCA信號線質量太差的原因，要換用質量好的RCA信號
線，并要遠離電源線。
1.檢查RCA信號線，其地線不能連接到汽車底盤。
2.檢查主機是否正確接地。
故障现象
失真
播放音樂時有嘶嘶聲
有嘯叫聲
引擎聲（靜態）
引擎聲（發電機火花聲）
產品啟動後保護指示
燈亮起或過熱保護
產品無輸出
產品不能啟動
1.檢查功放電源地線是否連接良好。
2.檢查電瓶正極電壓是否加在功放的電源端子正極。
3.檢查REMOTE電壓不要低於5VDC。
4.檢查電源端子正極電壓不要低於+12V。
5.檢查保險絲是否損壞（開路）。
6.確認保護指示燈是否亮起，如指示燈亮起則重新啟動功放。
7CN