Tech Support

To wire 2 x 4 Ohm speakers in Parallel to present a 2 Ohm load to the MS-AM702 Amplifier per channel. Simply follow the below diagram showing the Positive terminals from each speaker connected to each other and the same with the Negative terminals. Then connect the Positive and Negitive wires from the closest speaker to the Stereo.

The simple answer to this question is higher output power  (more Watts) and reduced current draw (play your music for longer periods). To give you a comparison between Class AB and D class, the normal output of a standard Head Unit  ( class AB) is say 40-50 watts Peak per channel. The Fusion 600 Series Head Units  (MS-CD/IP/AV600   D Class) have a rating of 70 Watts per channel and due to their  efficiency consume less power per Watt of output. In essence you can go louder for longer.  The other major benefit is that the D Class amp in the 500 and 600 series is that it's 2 Ohm stable (stereo).What this means is that you can conect 2 x 4 Ohm speakers per channel in  parallel wiring configuration. This produces more power but is divided between the 2 speakers. Eg. at 4 Ohms per channel ouput is 26 watts RMS and at 2 Ohms it is 43 watts RMS, so divided by two is 21.5 watts RMS per speaker.

The theoretical efficiency of class AB is about 75% as well with a real efficiency between 50%-70%; the theoretical efficiency of class D is about 100% with a real efficiency of more than 85%.The Fusion D Class  Marine Zone amp  MS-AM702 is a perfect example of a compact high output solution for the boating enthusiast that loves their music. loud

Some Mono block (single channel) amplifiers have 4 speaker output  terminals as shown below. These are internally linked Positive together and Negative together, this is to make connection to multi coil Subwoofers easier when you configure in parallel. You can connect each coil directly to the terminals (one per side) rather than at the subwoofer. 

The Inline fuse should be fitted as close to the battery as possible and the rating (amperage) the same or higher than the total on board fusing of your Amplifier. This fuse is to protect the power cable from  grounding and potentially starting a fire. 

    My speakers are 300 watts “MAX” and 90 watts “Rated Power” what size amp     
    do I need to drive them to achieve the best performance.  
  
 

 . When you are choosing an amplifier to drive speakers or a Subwoofer you should  
    use the “RMS” per channel ratings(Amplifier) and the “Rated Power”

   (Speaker/Subwoofer) as the reference for your choice. Always define which
    ratings you are comparing and try and get them as close as you can.                                                                                                     

    “Max/Peak” Power Rating
    The “MAX/PEAK” power rating of a speaker is the amount of power
    that the speaker can handle in short bursts or peaks without causing
    permanent damage to the voice coil.If this rating is exceeded constantly
    you will risk burning the voice coil.
 
     “Rated Power” Power Rating  
     The “Rated Power” rating of the speaker is generally considered to be the
     nominal constant power that the speaker will handle continuously
     without causing damage.
 
     Therefore if your speakers are rated at 90 watts (Rated Power) you should drive   
     them with an amplifier that is capable of supplying 90 watts RMS per
     Channel or as close to that as possible. That is not to say that an amp
     capable of a higher output cannot be used if the amplifier settings are
     managed responsibly realising the potential to overdrive your speakers
     exists. This rule also applies to using an amplifier that is under driving
     your speakers. Constantly driving a distorted signal from an overdriven  
     Source to your speakers can cause damage to the voice coils
 

Bridge mode is commonly used to get more output power from amplifiers by combining two single channels output into one output. This can only be done safely if you know the minimum load (Ohms) permissible when bridged. This is more common when driving Subwoofers that have Dual voice coils or when you have multiple Subwoofers. First check the installation manual or look at the speaker  terminal block on the amplifier as they normally have a diagram showing the bridged connections.

This is an example of a 4 channel amp speaker connection terminal block. As shown bridging is achieved by connecting the positive terminal from the left channel and the negative terminal of the right channel to the corresponding terminals on the subwoofer coil or coils depending on configuration. There are a number of different configurations depending on the load applied to the amplifier. See Subwoofer coil configuration.  It all depends on whether you have a  4 Ohm, 2 Ohm or 1 Ohm stable amplifier (mono). An example of the different power ratings for a four channel amplifier  are as follows.

100 Watts RMS x 4 @ 4 Ohms
200 Watts RMS x 2 Bridged @ 2 Ohms

These are examples only to give you an idea how this works. This also applies for  2 channel amplifiers and  depends on whether they  class AB or  D class amps as the 1 Ohm rating applies to D class amps in general.
   

If the protection LED is illuminated this indicates the Amplifier is in protection mode due to a fault condition. There are numerous causes for this and it may mean the Amplifier will need to be inspected and diagnosed by a Technician. It may also be a speaker or subwoofer causing the fault condition.
To eliminate this as a possible cause disconnect the speakers  or subwoofer from the output of the amplifier . If the Amplifier still goes into protection mode with nothing connected to the out terminals this indicates a fault with the amplifier.
 

When running power cable for Amplifiers it is wise to calculate what the voltage drop will be especially if you are using long runs . The below table will help you to calculate  the correct size cable you require. 

 
The gain or level pot is not a volume knob, it is used to match the relative output level (voltage) of your source unit  to the input circuit of your amplifier. The gain control determines how far you have to increase the volume on your source unit for the amplifier to reach full power. If you have your gain set too low your amplifier will not be able to reach full power and this could allow the source unit to clip which in turn will result in a distorted signal being delivered to your speakers. This is especially relevant with low voltage sources (lower than 2.5volts typically OEM units). With higher voltage sources (2.5volts or higher) if the gain is set too high the amplifier will be able to reach full power at a lower volume control setting from the source unit. This will allow the amplifier to be driven into clipping. The gain settings should generally be set lower, meaning a higher setting on the volume control of the source, to minimize amplifier clipping.

Guide to Setting Gain Control

 If you do not have the correct equipment (oscilloscope)  this may help        
 you to set your gain.
 

1. Once you have installed the system power it down.

2. adjust the amplifier gain to the minimum.

3. power up the system and adjust the volume control of your source unit

   to about 3/4 of the way up.

4. slowly increase the gain control until it reaches the maximum level you 

   are comfortable with or until it starts to clip, and then reduce the level

   until you are happy that you will not damage your speakers or Subwoofer.
 

Before any wiring and installation is performed, FUSION recommends you first plan the complete installation. Look at wiring routing, amplifier location and fitment. Please re-check the installation at completion

.
Appropriate mounting is very important for prolonged life expectancy of any amplifier. Select a location that allows enough space so sufficient airflow is maintainable and a location that provides protection from moisture. Keep in mind that an amplifier should never be mounted upside down. Upside down mounting will compromise heat dissipation through the heatsink and could engage the thermal protection circuit.
Excessive heat will shorten your amplifiers life. To maximise heat dissipation, be sure to leave at least 2.5 inches of clearance around the amplifier. If space is of the essence and the amplifier must be mounted in an enclosed or restricted area, a small 3 inch fan should be used in correspondence with a duct so the heat can flow past the heat sink.

WARNING: Do not mount any amplifier on a subwoofer enclosure as extended exposure to vibration may cause malfunction of the amplifier

INSTALLATION WARNING
1: Ensure the vehicle 12 volt lead is removed from the battery before any equipment is connected
2: Investigate the vehicles gas tanks, brake lines and electrical wiring locations before you begin installation
3: Attach the product securely to the vehicle to prevent damage in the event of an accident
4: Ensure all wiring is protected to avoid damage or pinching of the cables

WIRING
Make sure before any connection is made to the amplifier or source unit, ensure that you turn the audio system off. Failure to do so could result in either the stock system or your new FUSION product being damaged. FUSION will not warranty damaged amplifiers due to incorrect installation.
When wiring  FUSION amplifiers, ensure that the wires are away from sharp objects and that rubber grommets and insulated bungs are used when wiring through door jams and any other steel panels.

CONNECTION
Note: Ensure the audio system is off during the installation of FUSION product. Once the installation is complete FUSION recommends that you turn the volume of the source unit up slowly so not to damage the speakers. Please recheck the complete installation prior to turning the audio system on.

GROUND/EARTH
Always ensure that the ground connection point is a clean bare metal connection and it is a good idea to apply silicone over the bolt and connection to prevent rust forming. If the amplifier is powered on without an Earth connection or a poor connection this will cause damage to the amplifier and / or head unit as it will try to find an earth via the least path of resistance which could be through the RCA connectors back to the Head Unit . This will burn the Earth track on the Head Unit or it may go through the chassis of the Amp to the floor of the car. This is traceable by a technician to verify the cause of the damage.
 

My Amplifier isn’t working.

- Check to see which, if any, LED  indicator is on.

 No LED
-       If neither indicator is on first check your inline fuse in the power cable near the battery. (If blown replace with the same rated fuse ).
-       Ensure the Earth/Ground and power connections on the terminal block of the Amplifier are clean and tight.
                                                                                                    
-       Ensure your remote wire has a good connection at the amplifier and Head Unit/Source.   
-       Check amplifier fuses, if blown replace with the same rated fuse but if they fail again you may have a problem in your amplifier circuit.
        Do not replace with a higher rated fuse as this could result in major damage.
-       If the problem persists please consult your authorized dealer at your place of purchase.

Protection LED On
-      If the red protection LED is on it may be that the amp has gone into Thermal protection (overheating).
-      Let the amp cool down for 15-30 minutes and try again.
-      If the amp still goes into protection it could be the result of a speaker/sub problem, disconnect the speaker/sub from the amp and turn the amp on.
       If the power indicator comes on and stays on that would indicate that you have a problem with your speaker/sub.
-      If the protection LED comes on you may have an intenal problem with your amp.
-      There could be a fault that needs professional diagnosing and servicing.
-      If the problem persists please consult the authorized dealer at your place of purchase.
      
 Power LED On No Sound
-      This can indicate that the amp is not receiving a signal from the head unit/source, check your RCA cables and settings.
-      Check the wiring connections on the output of your amp and the subwoofer.
-      You may have a problem with the output circuit of your amplifier.
-       If the problem persists please consult the authorized dealer at your place of purchase.