There are many types of boats, in different sizes and styles. In addition we all have our different needs and requirements. BUT, the foundation (blue print) is still the same. For a good marine install the design of the system is as critical as the components and/or installation. When designing a balanced sound system in a marine environment, we need to look at a few requirements such as the source (head unit/radio), speakers, subwoofers, amplifiers, installation more carefully.

The Source: There are many manufacturers that are offering marine audio units. Our choices vary from a simple AM/FM/CD units to AM/FM/ CD controller/MP3/XM digital satellite radio and more. CD Changers tend to skip less than in-dash units. It is important to replace the radio with a unit that will have proper signal/preamp to control external amplifiers, preferably 4 volts of greater (preout). The high level preout will also run the audio system more efficiently. Having three pairs of pre-amp RCA output will allow us to add a 5 or 6 channel amplifier with separate controls from the radio to each speaker, especially the subwoofers. Good LCD or other displays are very important in overcoming the direct sunlight.

Amplifier: The amplifier is at the heart of the audio system, giving us the full and clean power to run the speakers properly. A well-balanced setup will consist of at least one 4 channel amplifier. One half oth the amplifier will run the 2 or 4 speakers (6"x9" or two ways) using the internal cross over as high pass (100 hz), and the other part will power the sub using the low pass (80 hz) cross over. The speakers will play in stereo while the subs will be bridged mono. It is important to utilize an amplifier that is stable at 2 ohm and wire the speakers for 2 ohm load. The charging systems in boats are low and power is limited; therefore, efficiency is very important.

Speakers: Every boat will have at least four 2-way speakers. The speakers should be mounted as high as possible with some space behind. XTC baffles can be used to isolate the rear of the speakers from the open area. In some cases, using components will assist in lifting the staging upward. Marine speaker baskets or frames are usually coated (white) to prevent rust, and the speakers are made of polypropylene. They are considered water resistant and will last for a few seasons.

Subwoofer: Adding at least two 10" subwoofers to the audio system will bring the sound to complete. It will enhance the lower frequencies. Since bass is non-directional, it can be installed in many positions/locations of the boat. A few manufacturers are building special subs for the marine environment. With some subs, the area should be sealed (build enclosure) to house the subs. Some are designed to work in an area under seat compartments without designing a special enclosure. That's known as infinite baffle.

Battery: Adding a separate battery to run the audio system is important. Using a deep cycle battery with proper protection as well as a master switch or 200 amp solenoid isolator will allow the system to play off the auxiliary batter without interfering with the main battery. Therefore, the latter will always be available to start the boat regardless of the auxiliary battery power availability. Please note that when adding multiple additional batteries the alternator must be upgraded as well as the charge line.

Antenna: There are hidden antennas that can be used to assist in receiving AM/FM. In addition, XM Radio antennas for marine are becoming available. Grounding the antenna lead to a rail works very well.

Options: I highly recommend to use XM Radio for boats. You will find all you need without having to deal with skipping CD's. With XM Radio there are 100 digital radio signals with no interference anywhere on most of the stations.
Speaker grills can be painted to match the exterior of interior color of boats and contribute to adding the rich looks of the boat.
Additional master controllers can be installed near the driver, by the gauges, or by the rear of the boat for ease of access to the operation of the system.

Installation: Installation knowledge and experience is as important as the components and setup/blue print. Purchasing the proper installation material will result in maximizing the potential of the electronic components.

Proper power/ground cables, connectors, RCA, speaker wire, circuit breakers, fuse blocks and more will add to the cost of the system. Too many times people forget and skimp on one important factor. The strength of the system is determined by the weakest point.

Proper connections will assist in lowering the potential of corrosion and other problems.

Placing all electronics in a cool and dry location is very critical. In some cases the engine compartment works very well. We must also be very careful with the location of the speakers. Grills must be mounted very securely with additional silicone for added protection. Marine audio covers are available, but still be aware of water reaching the back of the unit. Non of the electronic components take well to water. We should also take into consideration other areas of the boat that may receive water during boating.

Powerful Audio System: When we look at the larger marine audio setups, we find the following: multiple deep cycle batteries for more voltage and current, larger alternator to charge the batteries properly, main power protection cut-off switch with larger power and ground cables. In most cases, about eight mids are placed around the boat with eight tweeters. In addition we can find at least two 12" subs with four 10" subs. An internal or external electronic cross over is necessary. For source/head unit, XM radio is becoming very common, as well as MP3 units with CD changers. In many cases two additional control panels are utilized for flexibility of controlling the source and volume. Fiberglassing areas to accommodate maximum air space for subs is very common on large setups. This kind of setup can take a good 5-7 working days and about $10,000 plus…

Product: I would recommend looking at the following product that have been tested and is widely used.

Adding a full audio system in a boat will enhance the quality of leisure ime. But remember the importance of the system design and installation.

Have a fun summer…

  Car Audio and Electronics September 2002