Harman MS-12SD2, MS-12SD4 Choosing An Enclosure, Connecting Your Subwoofer To Your Amplifier

Thank you for purchasing an MS Series subwoofer. Subwoofer installation requires woodworking skills and some experience in disassembling and reassembling automotive interiors. If you lack the tools or necessary skills, have your subwoofer installed by an authorized JBL® dealer.

warning: Playing loud music in an automobile can permanently damage your hearing as well as hinder your ability to hear traffic. We recommend listening at low levels while driving. We accept no liability for hearing loss, bodily injury or property damage resulting from use or misuse of this product.

CHOOSING AN ENCLOSURE

MS Series subwoofers are optimized to perform best in small, sealed and vented enclosures. While infinite-baffle mounting of MS subwoofers is possible, power handling will be greatly compromised because there will be no enclosed volume of air to prevent the speaker’s cone from moving past its limit. For this reason, we do not recommend infinite- baffle mounting for MS subwoofers.

You should choose the enclosure you will use based on the type of music you listen to, how much amplifier power you will use for the subwoofer and how much space inside the vehicle you can devote to a subwoofer enclosure.

Because a sealed enclosure provides the most control over the woofer’s movement, a woofer mounted in a sealed enclosure will handle more power than a woofer mounted in another enclosure type. Sealed enclosures provide more accurate sonic reproduction than other enclosure types when mounted inside a vehicle, so they are well suited to all types of music. Sealed-enclosure construction is straightforward, and there are many prefabricated sealed enclosures available. An optimum sealed enclosure is always smaller than other types of enclosures optimized for a particular speaker, so they require the smallest amount of space inside the vehicle.

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Vented enclosures provide better efficiency in the 40Hz – 50Hz range, but this efficiency comes at the expense of sound in the lowest octave (below 40Hz) and at the expense of some control and power handling at the lowest frequencies. If you are using a small amplifier, a vented box will provide more perceived bass output from less power. Vented enclosures are also well suited to a variety of music types. Because vented enclosures require the volume of the enclosure and the size of the port to have a specific relationship with the characteristics of the woofer, the enclosure must be built exactly to the specifications provided. While there are some prefabricated vented boxes available, matching a prefabricated box to a particular woofer is difficult. If you wish to use a vented enclosure, we strongly recommend having your authorized JBL dealer build it or verify that your design is correct if you wish to build it yourself. An optimum vented enclosure is always larger than the optimum sealed box for the same woofer and will require more space inside the vehicle.

CONNECTING YOUR SUBWOOFER TO YOUR AMPLIFIER

JBL MS Series subwoofers are available in two different configurations:

adual two-ohm voice coil or dual four-ohm voice coils. You may use MS subwoofers in singles or multiples to maximize the power available from your amplifier(s). To achieve the maximum amplifier output possible, you should design a speaker system that provides the lowest impedance that your amplifier will drive safely. When designing a subwoofer system, consider the following rules:

1.Do not mix different subwoofers or enclosure types in the same system. Subwoofers being used in the same enclosure or powered by the same amplifier should be identical models. Mismatched woofers and enclosures can result in poor performance from your subwoofer system.