MXB 5900i - Car radio Crunch - Free user manual and instructions

Product Type	5-Channel Car Audio Amplifier
Brand	Crunch
Model	MXB 5900i
Channels	5 (4 full-range + 1 subwoofer)
RMS Power @ 4 Ohms	4 x 75W + 1 x 225W
RMS Power @ 2 Ohms	4 x 125W + 1 x 400W
Max Power	4 x 150W + 1 x 450W (estimated)
Frequency Response	20Hz - 30kHz (-3dB)
Signal to Noise Ratio	>90dB
Total Harmonic Distortion	<0.1%
Input Sensitivity	0.2V - 4V
Input Impedance	47 kOhms
Damping Factor	>150
Crossover Type	Variable Highpass/Lowpass (12dB/octave)
Highpass Crossover Range	60Hz - 1.2kHz
Lowpass Crossover Range	40Hz - 150Hz
Subsonic Filter	15Hz - 55Hz
Bass Boost	0dB - +12dB @ 45Hz
Fuse Rating	1 x 70A
Dimensions (W x H x L)	230mm x 53mm x 530mm
Weight	Approx. 4.5 kg (estimated)
Mounting	Rear trunk or under seat, ensure ventilation
Remote Control	Included wired remote for subwoofer level

Frequently Asked Questions - MXB 5900i Crunch

What is the power output of the Crunch MXB 5900i?

The MXB 5900i delivers 4 x 75W RMS + 1 x 225W RMS at 4 ohms, and 4 x 125W RMS + 1 x 400W RMS at 2 ohms.

Why is the Protect LED illuminated red?

The red Protect LED indicates a fault: overheating, shorted speaker wires, overload (too low impedance), or internal damage. Check cooling, wiring, and speaker impedance.

How do I set the input level (gain) correctly?

Turn the INPUT LEVEL control to '5V' position. Set head unit volume to 80-90% of max. Increase INPUT LEVEL clockwise until distortion is heard, then slightly reduce until clean.

What is the minimum speaker impedance per channel?

Minimum per channel is 2 ohms. Lower impedance causes excessive heat and may trigger protection mode.

How do I connect the amplifier for a 5-channel system?

Connect RCA cables from head unit to LINE INPUT 1/2 and 3/4. Use LINE OUT to connect to an external mono amp if needed. Connect speakers to respective channels: front, rear, and subwoofer.

What happens if the amplifier goes into protection mode?

If Protect LED lights, disconnect RCA and speaker leads. Reconnect power and remote; if LED still on, internal fault. If not, reconnect RCA first, then speakers one by one to isolate the faulty component.

Can I use the bass boost feature?

Yes, Bass EQ (0dB to +12dB) is available on Channel 5. Use cautiously to avoid clipping or overload. Start with low boost and adjust by ear.

How do I select the crossover mode for front speakers?

Use the X-Over switch: HPF for high-pass (small speakers), FULL for full-range, or LPF for low-pass. Adjust the frequency regulator accordingly.

What is the subsonic filter and how should I set it?

The subsonic filter eliminates very low frequencies (15-55Hz) to protect subwoofers. Set it just below the subwoofer's tuning frequency, typically around 20-30Hz.

What should I do if I hear a whine that changes with engine RPM?

This is alternator noise. Check RCA cable routing away from power cables and fuel pumps. Ensure head unit ground is directly connected to chassis. Clean power supply from battery may help.

USER MANUAL MXB 5900i Crunch

Black and white hazard symbol with radiating lines and lightning bolts, no text or numbers present.

BLACKMAXX

CAR AUDIO AMPLIFIERS

MXB5900i·MXB1200i

Bedienungsanleitung

Illustration of a hand holding a black and white abstract symbol resembling a stylized flame or explosion (no text or symbols present)

Installationshinweise

3D rendering of a mechanical component with mounting holes and a central spiral pattern (no text or symbols)

Top-down line drawing of a car viewed from the side, showing front, rear, and side views (no text or symbols)

Kabelanschlüsse

Top-down line drawing of a car viewed from the side, showing front, rear, and side views (no text or symbols)

Kabelanschlüsse

Top-down line drawing of a car viewed from the side, showing front, rear, and side views (no text or symbols)

Kabelanschlüsse

General Installation Notes,

Installation of the amplifier, Electrical Connection 12

Monoblock Amplifier

Monoblock Amplifier - Features 13

Loudspeaker wiring and Connections

2 Channel Amplifier in Stereo Mode 14

5-Channel Amplifier

5-Channel Amplifier - Features 15

Loudspeaker wiring and Connections

Stereo Mode with Front-/Rear Speakers with Subwoofer 16

One 3-Channel Amplifier with bridged Front-Speakers and a Subwoofers 17

Specifications 18

Trouble Shooting 19

DUAL-ILLUMINATION SWITCH

This switch changes the colour of the illuminated Logo-Badge.

ON PRESS: BLUE OR WHITE LED-ILLUMINATION

Illustration of a hand adjusting a black and white circular object with a central hole (no text or symbols)

General Installation Notes

The amplifier is generally mounted in the rear trunk area but can be mounted in any convenient area such as beneath a seat. Please be sure to locate this unit where you have reasonable air circulation and protection from moisture. When considering the mounting location you should minimize the length of the power and speaker leads. Minimizing both leads will yield a more reliable installation. It is also important to ensure that the heat sink fins are not against a panel or a surface, preventing air circulation. Do not install the amplifier on a subwoofer box or on vibrating parts of the vehicle, since the vibrations can cause damage to the amplifiers electrical components.

Installation of the amplifier

Mark the location for the mounting screw holes by using the amplifier as a template. Drill holes at the marked locations and firmly fasten the amplifier in place with the mounting screws supplied in the accessory kit. Before drilling or cutting any holes, investigate the layout of your automobile thoroughly:

Take care when working near the gas lines or hydraulic lines and electrical wiring.

3D diagram of a mechanical component with mounting holes and a central spiral pattern (no text or symbols)

Electrical Connection

Ground (GND)

This wire is the electrical ground and must be fastened securely to the vehicle chassis. The best method is to use a threading sheet metal screw since the threads cut into bare metal. Ensure that all paint or other insulation is remove from around the hole area, and using self tapping screw, securely affix the bare wire ends to the vehicle chassis. Use as short a piece of cable as possible - use the same gauge as was used for the +12V cable. Make sure that the connection is safe, a loose connection may result in amplifier noise and fault condition.

Remote (REM)

Many radios or other music sources have an output terminal for connection of the remote turn-on of the power amplifier. If a radio doesn't have a remote turn-on feature, then you can use the antenna relay wire, which activates the antenna motor. Please note, if the power antenna retracts when the radio is operating, then you cannot use the antenna relay wire to operate the remote turn-on.

Battery Connection (+12V)

This wire is usually connected directly to the positive battery terminal. Ensure that the + power supply wire is fused via an assigned fuse in line with the + power supply wire. Please use a sufficient gauge for the installed amplifiers. This connection must be completed using spade lug with insulating sleeve.

Fuses

The integrated amplifier fuses protect the units from short circuit and overload. The fuse rating is for 4 Ohm loads (impedance) of the speakers, for 2 Ohm loads the fuses may have to get increased by up to 50% in case of higher power consumption.

Power / Ground / Remote Connection

Monoblock-Amplifier - Functions and Controls

MXB 1200i

LOW PASS/SUB SONIC

LOW PASS -The built in low pass filter is fully variable from 35Hz to 250Hz,

SUB SONIC -Eliminates the lowest frequencies to protect the speakers from damages. These low frequencies can cause damages. The frequency is adjustable from 15 Hz to 35 Hz

Monoblock-Amplifier - Speaker wiring and Connection

MXB 1200i

Top-down line drawing of a car viewed from the side, showing front, rear, and side views (no text or symbols)

Interconnect cable checklist:

• Connect the LINE INPUT of the amplifier to the head unit line output with good quality RCA to RCA cables.
• Connect the speakers with the terminal block (SPEAKER OUTPUT/ - LEFT + and - RIGHT +) of the amplifier.
  •The minimum final speaker impedance must not be below 2 Ohm per channel. Too low speaker loads result in too high heat dissipation and may cause the amplifier run into protection.
• Please observe speaker channel and polarity as printed by the speaker terminal block. Incorrect phasing of the speakers results in total loss of bass response.

Caution

Be careful not to connect speaker (-) to the ground or vehicle chassis.

INPUT LEVEL

• Turn the INPUT LEVEL control on the amplifier to 5V position.
• Turn the head unit volume control to about 80 - 90% of its full setting.
• Turn the INPUT LEVEL control clockwise until you hear some distortion.
• Then turn back the INPUT LEVEL control slightly until you can hear clean sound.

Low pass

- This eliminates the higher frequencies. Set the crossover-frequency between 50Hz-100Hz, depending of the size of the installed speakers.

Subsonic

- This eliminates the lowest frequencies and protects the speakers from damage.

Bass EQ

- Allows you to adjust the bass boost from 0dB up to 18dB

Caution! Please use the Bass-Boost carefully.

The additional boost may result in clipping or overload.

If you use more than one subwoofer you can optionally Use Channel two

Connection for Remote control

Connect RCA cable from head-unit with RCA input (LINE INPUT).

Minimum impendance not under 1 Ohm

5-Channel Amplifier - Functions and Controls

MXB 5900i

LOW PASS - Channel 5

Controls the frequency response of your speakers upwards. The Cut-off frequency is continuously variable from 30Hz up to 150Hz

Bass EQ- Channel 5

Continuously variable from 0dB up to +12dB.

Subsonic-Filter-Channel 5

Eliminates the lowest frequencies to protect the speakers from damages. Continuously variable from 15Hz up to 55Hz.

5-Channel Amplifier - Speaker wiring and Connection

MXB 5900i

Stereo-Mode (5-Channel - with Front-/Rearsystem and Subwoofer)

Top-down line drawing of a car viewed from the side, showing front, rear, and side views (no text or symbols)

Interconect Cable checklist :

• Connect the RCA outputs from head unit with the RCA Inputs (LINE INPUT 1CH&2CH / 3CH&4CH) of the 4 Channel amplifier with two RCA Cables.
• Connect the RCA outputs of the (LINE OUT) 4-Channel Amplifier with the RCA inputs(LINE INPUT) of the 1-Channel/Mono amplifier with an RCA cable.
• Connect the Front- & Rear-Speakers with a good RCA cable with the speaker outputs (SPEAKER OUTPUT/ + 1CH -, + 2CH -, + 3CH -, + 4CH -) of the 4-Channel amplifier.
• Connect the Subwoofer with a good RCA Cable with the Speaker outputs (SPEAKER / + -) of the 1-Channel/Mono Amplifier.
• The minimum final speaker impedance must not be below 2 Ohm per channel. Too low speaker loads result in too high heat dissipation and may cause the amplifier run into protection.
• Please observe speaker channel and polarity as printed by the speaker terminal

Caution!

Be careful not to connect speaker (-) to the ground or vehicle chassis.

X-Over- (Front-/Rearsystem 1 up to 4 Channel)

• When you use bigger speaker systems (∅20cm plus), set on FULL RANGE-position (FULL RANGE).
• When you use smaller speaker systems (Ø8.7cm - Ø16cm), set on HIGHPASS- position (HIPASS). The cut-off frequency should be between 60Hz - 150Hz. It is controlled by the HIPASS-regulator.
• The cut-off frequency should be between 60Hz - 150Hz. It is controlled by the Lowpass-regulator.

Subwoofer (Channel 5)

Bass EQ-(Channel 5)

- Allows you to adjust the bass boost from 0dB up to 12dB.

Caution! Please use the Bass-Boost carefully. The additional boost may result in clipping or overload.

Subsonic-filter (Channel 5)

- Eliminates the lowest frequencies to protect your Subwoofer from damages. Cut-off frequency should be between 20Hz and 55Hz

Level

• Turn the INPUT LEVEL control on the amplifier to 5V position.
• Turn the head unit volume control to about 80 - 90% of its full setting.
• Turn the INPUT LEVEL control clockwise until you hear some distortion.
• Then turn back the INPUT LEVEL control slightly until you can hear clean sound.

Mode

- Set mode switch on 5CH-position

graph TD
    A["Connect RCA Cables from head unit with RCA inputs (LINE INPUT 1CH/2CH & 3CH/4CH)"] --> B["CAUNCH"]
    B --> C["Subwoofer 2 - 8 Ohm"]
    B --> D["Front-Speakers 4 - 8 Ohm"]
    B --> E["Rear-Speakers 4 - 8 Ohm"]

5-Channel Amplifier - Speaker wiring and Connection

MXB 5900i

3-Channel - with Frontsystem and Mono/Subwoofer

Top-down line drawing of a car viewed from the side, showing front, rear, and side views (no text or symbols)

Interconnect cable checklist :

• Connect the RCA outputs from head unit with the RCA Inputs (LINE INPUT 1CH&2CH / 3CH&4CH) of the 4 Channel amplifier with two RCA Cables.
• Connect the RCA outputs of the (LINE OUT) 4-Channel Amplifier with the RCA inputs(LINE INPUT) of the 1-Channel/Mono amplifier with an RCA cable.
• Connect the Front- & Rear-Speakers with a good RCA cable with the speaker outputs (SPEAKER OUTPUT/ + 1CH -, + 2CH -, + 3CH -, + 4CH -) of the 4-Channel amplifier.
• Connect the Subwoofer with a good RCA Cable with the Speaker outputs (SPEAKER / + -) of the 1-Channel/Mono Amplifier.
• The minimum final speaker impedance must not be below 2 Ohm per channel. Too low speaker loads result in too high heat dissipation and may cause the amplifier run into protection.
• Please observe speaker channel and polarity as printed by the speaker terminal

Caution!

Be careful not to connect speaker (-) to the ground or vehicle chassis.

X-Over- (Front-/Rearsystem 1 up to 4 Channel)

- When you use bigger speaker systems (Ø20cm plus), set on FULL RANGE-position (FULL RANGE).

- When you use smaller speaker systems (Ø8.7cm - Ø16cm), set on HIGHPASS-position (HIPASS). The cut-off frequency should be between 60Hz - 150Hz. It is controlled by the HIPASS-regulator. When you use this configuration the LOPASS CONFIG - Switch is out of function.

Subwoofer (Channel 5)

•The cut-off frequency should be between 60Hz - 100Hz. It is controlled by the Lowpass-regulator

Bass EQ-(Channel 5)

- Allows you to adjust the bass boost from 0dB up to 12dB

Caution! Please use the Bass-Boost carefully. The additional boost may result in clipping or overload.

Level

• Turn the INPUT LEVEL control on the amplifier to 5V position.
• Turn the head unit volume control to about 80-90% of its full setting.
• Turn the INPUT LEVEL control clockwise until you hear some distortion.
• Then turn back the INPUT LEVEL control slightly until you can hear clean sound.

Mode

- If there is only one RCA output at your head unit, set mode-switch on 2CH-position. 5CH-Stellung bringen.

Connect RCA Cables from head unit with RCA inputs (LINE INPUT 1CH/2CH & 3CH/4CH)

Connection for Remote to adjust the subwoofer from your seat

Trouble Shooting

System does not turn on

1. Check all fuses.
2. Check all connections.
3. Measure the +12 volt and remote turn on voltages at the amplifier terminals. If these are non existent or low, take voltage measurements at fuse holders, distribution blocks, the head unit's +12 volt and remote leads to Localize the problem.

Noise problems

1. Check the speaker wiring
2. Speakers are damaged

No Signal at Channels

1. Set Balance and Fader from head unit on Zero-Position
2. Check wiring (Amplifier, Speakers)
3. Speakers are damaged

Hiss or white noise

1. Speakers are overload
2. High levels of white noise usually occurs when amplifier level controls are turned up too high - readjust according to the procedures in section "Setting up systems after installation for best performance"
3. Another major problem that can cause excessive hiss, is a noisy head unit - unplug the amplifier input RCA cables, and if the hiss level reduces, the source unit is at fault.

No Stereo-Sound or Low Output

1. Check speaker wiring (-and+)

Amplifier Protect-Mode (red LED is illuminated)

1. Speaker cables are shorted
2. Inadequate cooling - relocate or remount to provide better natural airflow over the fins. Driving high power levels into low impedances - back off on the volume control, and/or make sure you are not loading the amplifier with less than the recommended loudspeaker impedance.
3. Make sure that the battery voltage, as measured at the amplifier's +12 volt and ground terminals, is 11 volts or more.

Electrical interference

The inside of an automobile is a very hostile electrical environment. The multitude of electrical systems, such as the ignition system, alternator, fuel pumps, air conditioners to mention just a few, create radiated electrical fields, as well as noise on the +12 volt supply and ground. Remember to isolate the problem - first unplug amplifier input RCAcables, if the noise is still present, check the speaker leads, if not, plug the RCA's back, and investigate the source driving the amplifier, one component at a time.

A ticking or whine that changes with engine RPM:

1. This problem could be caused by radiation pickup of RCA cables too near to a fuel pump or a distributor, for instance, - relocate cables.
2. Check that the head unit ground is connected straight to the vehicle chassis, and does not use factory wiring for ground.
3. Try to supply the head unit with a clean +12 volt supply directly from the battery +, instead of using a supply from the in dash wiring/fusebox.
   This type of noise can be more difficult to pinpoint, but is usually caused by some kind of instability, causing oscillations in the system.

A constant whine:

1. Check all connections, especially for good grounds.
2. Make sure that no speaker leads are shorting to exposed metal on the vehicle chassis.
   3.RCA cables are notorious for their problematic nature, so check that these are good, in particular the shield connections.

Caution!

In your amplifier there are protection circuits integrated. Short Circuit Protection engaged: The amplifier will turn off and try to come back on immediately. The amplifier will cycle like this indefinitely, with "blips" of sound each time. If this is the case, check your speakers and wiring for low impedance and short circuits. Thermal Protection engaged: The amplifier will turn off and several minutes later will come back on. In this case, ensure that there is nothing blocking the normal convective airflow of the amplifier. No obstruction should be within 2" of the amplifier on all sides.

NOTE: Low battery voltage will cause the amplifier to run warmer and possibly damage the amplifier.

Specifications

	MXB-1200i	MXB-5900i
Channels	Monoblock	5-Channel
Output Power Ratings at 14.4 Volts
Watts at 4 Ohm load - RMS / MAX.	1 x 275 / 550	4 x 75 + 1 x 225
Watts at 2 Ohm load - RMS / MAX.	1 x 450 / 900	4 x 125 + 1 x 400
Watts at 1 Ohm load- RMS / MAX.	1 x 600 / 1200
Frequency response -3dB	10 Hz - 400 Hz	20Hz - 30kHz
Damping factor	>150	>150
Signal to noise ratio	>90dB	>90dB
Channel seperation	>70dB	>70dB
THD & N	0.10 %	0.10 %
Input Gain Control	0.2 - 4 Volts	0.2 - 4 Volts
Input Impedance	47 kOhm	47 kOhms
Crossover Channel 1 & 2
Full/Lowpass/Highpass	TP/Voll/HP	Full/LP/HP
Variable Highpass Crossover 12 dB	10 Hz - 40 Hz	60Hz - 1.2kHz
Variable Lowpass Crossover 12 dB	40 Hz - 400 Hz	40Hz - 150Hz
BassBoost Control at 45Hz	0dB - +12dB	0dB - +12dB
Crossover Channel 3 & 4
Full/Lowpass/Highpass	-	Full/LP/HP
Variable Highpass Crossover 12 dB	-	60Hz - 1.2kHz
Variable Lowpass Crossover 12 dB	-	40Hz - 150Hz
BassBoost Control at 45Hz	-	0dB - +12dB
RCA Line Outputs	Fullrange	Fullrange
High Level Inputs
Fuses	4 x 30 Ampere	1 x 70 Ampere
Heatsink size in mm
Width x Height	230 x 53	230 x 53
Lenght	430	530

*Subject to change without notice

CRUNCH

Distribution:

Audio Design GmbH

Am Breilingsweg 3

76709 Kronau

Tel. [phone], Fax [phone]

www.audiodesign.de

BLACKMAXX

CAR AUDIO AMPLIFIERS