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A Few Words About Enclosures
Your Decade Series subwoofer requiresYour Car and Bass Reproduction
an enclosure to realize its full low-Depending on the size of the vehicleOsIn addition, there are a number of points
frequency response. The speakerOs design interior listening space, reproducedyouOll want to keep in mind as you con-
is flexible enough to produce exceptionalfrequencies below 80Hz are actuallystruct an enclosure:
Thank youfor choosing a JBL Decadearesults no matter whether you specify aboosted by nearly 12dB per octave as 1. Use 3/4" (19mm) MDF (medium-density
Series subwoofer. Decade Series sub-small sealed, vented or bandpass enclo-frequency decreases. NOTE: This effect,fiberboard) or marine birch plywood to
woofers are designed to suit a broadsure. In vented and bandpass enclosures,known as the vehicleOs transfer function,build an enclosure. Enclosures for 12"
range of mobile-audio applications andbox size and port tuning frequency willplays an important part in shaping theand larger subwoofers, or small sub-
can be used in a wide variety of enclo-also help dictate the low-frequency overall in-car response and is displayedwoofers driven by high power ampli-
sure types to produce extended, powerfulperformance and output capability ofgraphically along with freespacefiers, should be constructed using 1"
bass in a limited amount of vehicleyour system. response on the enclosed data sheet for(25mm) material.
space. To ensure maximum subwooferyour Decade Series subwoofer.2. Seal all joints with glue and screws; do
performance, we strongly recommendYour Decade Series subwoofer will alsonot use nails. We recommend Odeck� or
that installation be left to a qualified pro-work in infinite baffle applications whereEnclosure Calculations andOzip� screws since they have coarse
fessional. Although these instructionsthere is no space or budget to build aBuilding Boxesthreads for better grip and donOt require
explain how to install a JBL Decadebox. Be aware that infinite baffle or OfreeUse the recommended box designs onpre-drilling holes. Once the box has
Series subwoofer in a general sense, theyair� mounting will reduce the power han-the enclosed data sheet. Choose cabinetbeen tested, seal all interior joints with
do not show box construction details anddling of any subwoofer compared to andimensions to fit your vehicle, but do notsilicone caulk.
exact installation methods for your partic-application using an enclosure. change the enclosureOs volume. Doing so3. Depending on the application, fill the
ular vehicle. If you do not feel you havewill change the tuning frequency of theenclosure according to the design you
experience, do not attempt the installa-Finally, any deviation from recommendedenclosure and may adversely affect finalhave chosen from the enclosed data
tion yourself, but instead ask your autho-enclosure volumes or port dimensionsperformance. If you cannot perform thesheet in one of three ways: zero-percent
rized JBL dealer about professionalshould be made using dedicated necessary calculations yourself, pleasefill (i.e., no fill), 50-percent fill (i.e.,
installation options.enclosure-design software, such as JBLcontact your authorized JBL dealer for1"-thick polyfill sheets on all inside
Speakershopa. If this type of software ishelp and for information about JBLwalls except where subwoofer is
Remember to keep your sales receiptnot available to you, look for assistanceSpeakershop, a dedicated enclosure-mounted), or 100-percent fill (i.e., entire
with this manual in a safe place so bothon JBLOs Web site at www.jbl.com or fromdesign software program for experiencedbox is stuffed with loosely packed poly-
are available for future reference.your authorized JBL dealer.car-audio enthusiasts.ester fiberfill).
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