Typical causes for little or no output

STEP 6. (6) TIME CORR. (Time Correction)

Due to the wide variety of installation and system design possibilities available, bass performance may not always be optimized as a result of speaker placement relative to the listening position. Sound waves may not reach the listener's ear at the same time as other speakers, especially in a multiple subwoofer configuration. Such differences in phase can result in muddy (unclear) bass or even a complete cancellation in the frequency response. Therefore, both the MRD-M300 and MRD-M500 are equipped with Digital Time Correction, making it possible to realign subwoofer(s) in time. Proper use of this function will result in clear, powerful bass with a smooth transition to the other speakers in the system. It is recommended to use the calculation formula provided in the owner's manual as a starting point for this adjustment.

STEP 7. (7) PHASE

Phase control allows you to flip the polarity of the subwoofer without actually reversing the physical connections. This convenient feature is useful when the subwoofer is in a position that could result in some cancellation, causing diffused, unclear bass. It is recommended to try both settings (0°/180°) to determine which is best for your particular system.

STEP 8. (8) AMP SET (Amplifier ID No. /Turn-On Delay)

The Amp Set menu performs two functions. Firstly, by setting the amplifier ID number (1-8), it allows the optional RACC (RUX-4280 Remote Amplifier Control Center) to identify each amplifier individually and in a specific order. Secondly, it provides a variable turn-on delay that can be used to minimize inrush current in large multi-amp systems, or to eliminate any turn-on “pop”.

NOTE: If using a RUX-4280 (RACC) with more than 1 AccuClass-D amplifier, be sure to set each amplifier with a different ID Number (1-8). Amplifiers with the same ID will cause the RACC to display "NO AMP."

STEP 9. (9) SAFE MODE (Output Disable)

SAFE MODE provides a simple way to safely adjust the all DSP functions with the amplification circuit turned off, eliminating the possibility of speaker damage during setup. When SAFE MODE is set to “ON”, it literally shuts down the high current draw output stage of the amplifier, and is essentially an “output disable” function. This is the only amplifier function that does not engage/disengage in real time, but requires the remote lead to be cycled off/on. Therefore, if it is accidentally set to “ON” during programming, there will be no output the next time the amplifier is activated. Additional uses include: bench setup with very small or low current DC supply, amp valet, and system troubleshooting.

SETTING SAFE MODE TO "OFF"

•Press and depress the "MODE" button until you are in mode "9" (SAFE MODE).

•Push "ENT" and push "ENT" again to select "9-1" (ON/OFF).

•Toggle until "OFF" is displayed.

•Push "DISP" to exit.

Note: This setting will not take effect until the amp is turned off and then on again.

START HERE

ENT

Toggle

DISP

S H

STEP 0. (0) MEMORY

Memory Mode allows you to store all amplifier settings in an auxiliary backup memory. Once stored, additional tweaks or adjustments can be made while retaining the ability to recall the original settings at a later time. Note: This is simply a convenience feature, since all settings are saved in real time as adjustments are made, and will remain even if power is lost during setup.

1)Safe Mode is on: Go to Step 9 (Mode 9 on the amp) and set to “OFF”, then cycle amp power.

2)Subsonic and LPF frequency selections overlap or are too close together: Adjust the crossover properly

3)If using RUX-4280 (RACC) remote subwoofer level is turned down : Make sure the RACC is in normal

display mode (voltage or temperature) and adjust the level control.

4)Defective or broken RCA cables): Replace RCA connectors

5)Blown fuse: Replace Fuse with proper value

6)Remote trigger is not active: Check remote turn-on lead with a voltage meter

7)Bad ground or power connection: Check and replace ground connector

To find out more, visit www.alpinetechcenter.com

MRD-M300, MRD-M500 specifications

The Alpine MRD-M500 and MRD-M300 are two powerful amplifiers designed to enhance the audio experience in vehicles, demonstrating Alpine's commitment to high-quality sound and innovative technology. Both models cater to car audio enthusiasts who demand exceptional performance and reliability from their sound systems.

The MRD-M500 is a monoblock amplifier that delivers an impressive 500 watts of RMS power at 2 ohms, making it an ideal choice for those looking to drive subwoofers effectively. Its robust power handling ensures that it can easily accommodate various speaker configurations, producing deep, impactful bass that enhances the overall soundscape of any sound system. The MRD-M500 features a compact design, allowing for easier installation in tighter spaces without compromising on power.

One of the standout technologies in the MRD-M500 is its Smart Technology, which includes a built-in thermal protection circuit that safeguards the amplifier from overheating. This ensures long-lasting performance even during extended playback at high volumes. Additionally, the amplifier features adjustable low-pass filters and bass boost controls, giving users the flexibility to tailor the sound to their preferences. The integrated speaker-level inputs make it compatible with factory radios, facilitating a straightforward upgrade path for those transitioning from stock systems.

On the other hand, the Alpine MRD-M300 offers an excellent balance of power and efficiency with a rating of 300 watts of RMS power at 2 ohms. This model is designed to be more compact and budget-friendly, making it an accessible option for newcomers to car audio. The MRD-M300 shares many of the important features of its higher-powered counterpart, including a variable low-pass filter and a bass boost function, allowing users to achieve a well-rounded sound profile.

Both amplifiers utilize Class D technology, which ensures high efficiency and minimal heat generation. This allows for longer listening sessions without the worry of thermal issues. Furthermore, the durable construction of both models ensures they can withstand the rigors of the automotive environment.

In summary, the Alpine MRD-M500 and MRD-M300 are designed for car audio enthusiasts seeking powerful, reliable amplifiers that deliver quality sound. With features like adjustable filters, built-in protection, and user-friendly connectivity options, these amplifiers are ready to elevate any car audio system to new heights. Whether you're looking for brute power or an efficient solution for your setup, Alpine’s MRD series amplifiers provide excellent choices to enhance your driving experience.