Marine Stereo Systems
There is nothing like a day on the water for putting a grin on your face. For some boaters, the grin gets even wider when there are good tunes playing. Yet, the marine environment is also hard on electronics, and a washed out busted stereo could also remove that grin away from your face fast.
That’s why you should be looking to marine stereos. The best components carry an IP (International Protection) rating. The higher the IP number, the higher the Moisture Resistance value with a rating of IPx4, the unit is protected from water being splashed on the unit from any direction. IPx5 indicates the resistance to water spray jets from all directions. IPx6 rating is for water projected from powerful nozzles from all directions. IPx7 units can survive accidental immersion in one meter of water for up to 30 minutes. IPx8 designation is for continuous underwater use.
Now let’s take a closer look on how to put a quality marine stereo system together.
Head Units / Black Boxes:
A head unit or a black box is the central component in a marine sound system. Depending on the model, these receive radio and satellite signals, and process music delivered by CDs and MP3s. Also many boaters are now also choosing units such as “ Fusions MS-IP600G
AM/FM/Sirius IPod Stereo Dock” which features the World's First internal iPod docking technology. With the MS-IP600G, your iPod actually sits inside the stereo, completely protected from the harsh marine elements. Fully integrated iPod user interface, dual mono subwoofer output, and ingenious behind the dash engineering all contained in a 100% aluminum chassis. Waterproof to IPX5 standards. iPod-style menu on the backlit stereo display is easy to use via a rotary encoder. It’s hard to beat the convenience and portability of carrying along and having all your favorite songs and music with you to enjoy stored handily away in an iPod.Also increasingly popular among boaters, a “black box” is just that, a box hidden away from view (and protected from the elements) that provides many of the same operations as a head unit. The boat owner operates the sound system from a compact, easy to install remote faceplate.
Amplifiers:
External amplifiers receive the output signal from the head unit or black box and boost the output power to improve music quality and volume through the speakers. Amp output and speaker power should be compatible to prevent damage to the speakers. Amplifiers need to be in a well-protected compartment with ample airflow to help carry away the heat they generate.
Wiring:
Plan wire runs to satisfy the opposing concepts of easy service and total concealment. You don’t want wires hanging out where they’re vulnerable to damage, but you want to get to them when necessary. Wiring and connectors, even though they are rated as “marine grade,” should be installed to provide the maximum protection and shelter from moisture.
Speakers:
Two-way speakers integrating both a woofer and tweeter are the most common. And these are often flush-mounted in a compartment bulkhead or seat base. This saves space, looks clean and provides a soundboard for the speaker. However there must be space behind the bulkhead for the speaker to fit, and to allow air movement when the speaker cone moves in and out.
Box speakers are self-contained, so they don't require a hole to be cut, making the job easier. The speaker enclosure is acoustically engineered to provide optimum performance. But these are bulky and sometimes not as attractive as a flush installation.
Bazooka-style speakers are technically very powerful “box” speakers, in that they are not flush-mounted to a bulkhead. They are typically installed on a wakeboard tower, above the heads of boaters, and aimed at the guy or gal on the ’board, tube or skis.
Some systems also feature a subwoofer, a booming large-diameter cone that accentuates the bass. Each system has just one, and it can be installed just about anywhere in the boat, but is often situated somewhere amid ship.
The Five-Foot Rule:
It’s important to remember that, on boats, the improper placement of stereo speakers can wreak havoc with the compass or other navigation equipment. The “five-foot rule” is meant to keep all such interferences at a safe distance. Yet, tech advances have also brought us ultra-low magnetic field speakers and special shielding to reduce the magnetic flux. According to manufacturers such as Poly-Planar, this permits installation of the speaker in close proximity to the navigational gear without interference.
Remote Controls:
If remote control units are used, they should be installed in locations that will provide easy access, and they must be waterproof, with an IPx6 or IPx7 rating. If the remote is hard-wired (wireless units are also available) protect the wire connections by coating them with Liquid Electrical Tape or CRC Premium Marine Electronics Grease.
Antennas:
AM/FM radio reception can be improved by using an amplified antenna, such as the “dipole unit” by Jensen Audio. An amplified antenna draws power from the boat battery, and in this case draws 6mA when the unit is turned on. In the realm of non-amplified antennas, Shakespeare makes a “on glass” antenna that uses clear tape to attach it to a window.
Today, there is also HD radio — a technology that allows AM/FM radio stations to transmit digital audio. All you need is a radio (or a converter to plug into the head unit) that will receive HD.
The HD system delivers clear reception, eliminates hiss, distortion and station drop-off. Plus you get information on the dial, such as traffic data, and stock info. Special antennas are available to enable optimum reception.
Satellite Radio:
Many marine sound systems today will also include Sirius Satellite radio capability. In addition to a compatible radio, you need a subscription to the service provider, as well as a special antenna mounted well away from any other antennas, with a clear view of the sky.
Power:
Many stereo systems require a continuous trickle of current from the battery to maintain the internal memory settings. With that type of system, if you disconnect the power, you’ll lose station presets and clock settings. And, if you don’t disconnect it and don’t use the boat for long periods of time, it is also possible to drain the battery. So it’s a good idea to wire the sound system to a dedicated switch that will eliminate the parasitic power drain that can leave your battery dead.
With a separate amplifier, you may have additional power requirements. Because the amp will be a power hog, it’s a good idea to have a dedicated battery for this purpose. A deep-cycle marine battery is ideal because it delivers power over a long period and can endure repeated discharge.
Today’s marine sound systems have been tremendously improved by advancements in technology that deliver superior sound and durability. Now there is really no reason to leave your music onshore.
Special Considerations to consider when installing stereo speakers:
Speakers are directional the sound is emitted in the direction in which they are aimed. In the confines of a cabin, the sound is reflected off solid surfaces, so aim is not as important. But outside, the sound has to compete with a lot of other noises, and the music just seems to evaporate into the surrounding air. So aim the speakers where listeners are most likely to be sitting or lounging about.
Because the sound is stereophonic, position the left and right speakers so they are both aimed toward listeners equally. If four speakers are installed, “cross-channel” them with one set of left/right speakers in the normal orientation and the second set of left/right speakers in reverse orientation. This prevents loss of left/right separation regardless of where you’re sitting.
Never install speakers in direct opposition to each other, because this will cancel the mid and upper range sound quality. If you must install the speakers across from and facing each other, at least offset them as much as possible and/or use angled speaker rings to send the sound in a direction not straight into the sound from the opposing speaker.
For optimum performance, wire the speakers so they are “in phase.” Speaker terminals are positive or negative, and you want to match the positive side of the speaker with the positive output terminal on the head unit or amplifier. If you ever reverse the wiring to out of phase, you will also suffer a loss of stereo’s potential sound quality. To determine which speaker terminal is positive, place an AA battery across the terminals and watch the speaker cone. When the positive end of the battery is connected with the speaker’s positive terminal, the cone will move forward. For future reference, mark that terminal as positive. To avoid confusion, wire all the positives first, then follow with the negatives.
High-power speakers don’t necessarily produce better quality sound; they do permit operation with a higher powered amplifier. Low power output by the amplifier doesn’t sound any better on higher power speakers than it will on speakers matched to the low power of the amp output. Although it is possible to connect more than one speaker per amplified channel, but if it is not done properly damage can result to both the amplifier, or the speakers.
Some Marine Stereo Choices from: Amazon Marine Stereo Components
Posted by blog.houseboatodyssey1.com at 7/7/2010 6:40 PM 
Categories: Buying Tips, Marine Stereo, Accessories, Various 101's
Tags: Speakers Units Antennas Marine Head Stereos iPod Amplifiers
Categories: Buying Tips, Marine Stereo, Accessories, Various 101's
Tags: Speakers Units Antennas Marine Head Stereos iPod Amplifiers
This is a very thorough description of marine stereo systems. You covered it from every angle and in great detail. From all the music lovers on the water . . . thank you!
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