JBL Introduction / Installation J B L Basstu B E BTX250, Instructions BTX250, Hearing Warning

Introduction / Installation J B L BASSTU B E BTX250

Thank you for choosing the JBL BTX250. BTX250 has been designed to provide the kind of high-perfor- mance low-frequency reproduction that used to require big, clumsy enclosures, large amplifiers, and complex installa- tion. To ensure maximum performance, we strongly recommend that installa- tion be entrusted to a qualified profes- sional. Although these instructions explain how to install the BTX250 in a general sense, they do not show the specific installation methods for your particular vehicle. If you feel you do not have the necessary tools or experience, do not attempt the installation yourself; rather, ask your authorized JBL car audio dealer about professional instal- lation options.

Remember to keep this manual and your sales receipt in a safe place for future reference.

Instructions BTX250

Your car and bass reproduction Depending on the interior volume of your vehicle and the dimensions of the passenger compartment and cargo area, reproduced frequencies below 80Hz may be boosted by nearly 12dB per octave as frequency decreases. This effect, known as the vehicle’s “transfer function” or “cabin gain,” plays an important part in shaping the overall in-car response of the BTX250. BTX250 is designed to reproduce fre- quencies below about 100Hz, but there may be other speakers in your vehicle that reproduce some of those same frequencies. It is important that all the speakers work together to reproduce frequencies they share. Depending on the orientation of the BTX250 and the distance from it to the other speakers, the BTX250 and the other speakers may be "in-phase" or "out-of-phase". The resulting condi- tions, known as constructive and

INSTALLATION

CHOOSING A MOUNTING

LOCATION

Choose a location that doesn’t interfere with the loading or unloading of cargo, fold-down rear seats, or opening or closing of the trunk lid. The best loca- tion is likely to be the front or rear cor- ner of the trunk or luggage compart- ment.

These locations, in addition to being out of the way, will provide the best sonic reproduction in the 60Hz to 100Hz range because the woofer out- put will be “corner loaded” against the vehicle’s walls. In any case, BTX250 must not interfere with the safe opera- tion of the vehicle.

Once you’ve chosen a mounting loca- tion and made the necessary electrical connections, you’re ready to mount BTX250 securely to the mounting sur- face (most likely the floor of the lug- gage compartment).

the right place where the BTX250 will be installed and mark the exact posi- tion where the fixing holders will be located (figure 1). Then remove the fix- ing holders from BTX250. Screw the fixing holders on the position marked initially (figure 2). Put back in place the BTX250 in the fixing holders and press the lock to fasten the metal bar in posi- tion (figure 3).

Figure 1

Hearing WARNING!

Playing loud music in a vehicle can permanently damage your hearing, as well as hinder your ability to hear traf- fic. We recommend using low volume levels while driving. JBL accepts no lia- bility for hearing loss, bodily injury or property damage resulting from the use or misuse of this product.

destructive interference, also play a role in shaping the frequency response of your system.

Fortunately, BTX250 has controls to optimize both of these conditions and their adjustment is explained later in the manual.

Caution: Make sure mounting screws will not puncture wiring harnesses, brake or fuel lines, or the vehicle’s fuel tank. Some or all of these may be located behind or under the mounting surface.

Horizontal Mounting: Lock the fixing holders supplied (x2) on the metal bar of the BTX250 on each side. Then find

Figure 2

Figure 3

2