User manual JBL MR-CENTER

[. . . ] For this reason, we do not recommend infinite-baffle mounting for GT Series 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 moreaccurate 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. 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. 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. If you are designing a multiplewoofer system, be sure to configure the woofers so that they each receive the same amount of power from the amplifier. Never connect two identical woofers in series and then connect that pair to another woofer in parallel. If your system will include an odd number of woofers, be sure to connect all the woofers in either series or parallel according to the rules that follow, in order to maximize the power available from your amplifier: a. The total system impedance of voice coils (or woofers) in series can be calculated using the formula: Impedance = w1 + w2 + w3 . . . The total system impedance of woofers in parallel can be calculated using the formula: 1 Impedance = 1 1 1 + w + w . . . The diagrams at right show series and parallel speaker connections. To Amp To Amp Positive Negative To Amp To Amp Positive Negative Figure 1. Connecting two woofers in series to the amplifier (8 ohms) Red Positive Red Positive Black Negative Black Negative Red Positive Red Positive Black Negative Black Negative Series connection o Series connection o To Amp Positive To Amp Positive To Amp Negative To Amp Negative Figure 2. Connecting two woofers in parallel to the amplifier (2 ohms) Red Black Positive Red Positive Negative Black Negative Red Positive Red Positive Black Negative Black Negative Parallel Connection of tw Parallel Connection of tw To Amp To Amp Positive Negative To Amp To Amp Positive Negative 3 SPECIFICATIONS GT5-10 Power Handling, RMS Power Handling, Peak Sensitivity (2. 83V/1m) Frequency Response Impedance Mounting Depth Cutout Diameter Overall Diameter 250W 1000W 91dB 30Hz – 500Hz 4 Ohms 5-15/16" (151mm) 9-3/16" (233mm) 10-3/8" (264mm) GT5-12 275W 1100W 93dB 23Hz – 450Hz 4 Ohms 6-7/16" (164mm) 11-1/4" (286mm) 12-5/16" (313mm) MR-CENTER 300W 1200W 96dB 20Hz – 400Hz 4 Ohms 7-5/16" (185mm) 14" (355mm) 15-7/16" (391mm) 10" (250mm) Single 4-Ohm Subwoofer 12" (300mm) Single 4-Ohm Subwoofer 15" (380mm) Single 4-Ohm Subwoofer A valid serial number is required for warranty coverage. [. . . ] Connecting two woofers in series to the amplifier (8 ohms) Red Positive Red Positive Black Negative Black Negative Red Positive Red Positive Black Negative Black Negative Series connection o Series connection o To Amp Positive To Amp Positive To Amp Negative To Amp Negative Figure 2. Connecting two woofers in parallel to the amplifier (2 ohms) Red Black Positive Red Positive Negative Black Negative Red Positive Red Positive Black Negative Black Negative Parallel Connection of tw Parallel Connection of tw To Amp To Amp Positive Negative To Amp To Amp Positive Negative 3 SPECIFICATIONS GT5-10 Power Handling, RMS Power Handling, Peak Sensitivity (2. 83V/1m) Frequency Response Impedance Mounting Depth Cutout Diameter Overall Diameter 250W 1000W 91dB 30Hz – 500Hz 4 Ohms 5-15/16" (151mm) 9-3/16" (233mm) 10-3/8" (264mm) GT5-12 275W 1100W 93dB 23Hz – 450Hz 4 Ohms 6-7/16" (164mm) 11-1/4" (286mm) 12-5/16" (313mm) MR-CENTER 300W 1200W 96dB 20Hz – 400Hz 4 Ohms 7-5/16" (185mm) 14" (355mm) 15-7/16" (391mm) 10" (250mm) Single 4-Ohm Subwoofer 12" (300mm) Single 4-Ohm Subwoofer 15" (380mm) Single 4-Ohm Subwoofer A valid serial number is required for warranty coverage. Features, specifications and appearance are subject to change without notice. [. . . ]