Infinity 1011w, 811w, 1211w FEW Words about Enclosures, Enclosure Calculations and Building Boxes

WARNING: Playing loud music in an automotive environment can permanently damage your hear- ing, as well as hinder your ability to hear traffic. The maximum volume levels achievable with Infinity speakers, combined with high power amplification, may exceed safe levels for extended listening. We recommend using low volume levels when driving. Infinity accepts

no liability for hearing loss, bodily injury, or property damage as a result of use or misuse of this product.

A FEW WORDS ABOUT ENCLOSURES

Your Reference Series subwoofer requires an enclosure to realize its full low- frequency response. The speaker’s design is flexible enough to produce exceptional results no matter whether you specify a small sealed, vented or bandpass enclo- sure. In vented and bandpass enclosures, box size and port tuning frequency will also help dictate the low-frequency performance and output capability of your system.

Your Reference Series subwoofer will also work in infinite baffle applications where there is no space or budget to build a box. Be aware that infinite baffle or “free air” mounting will reduce the power han- dling of any subwoofer compared to an application using an enclosure.

Finally, any deviation from recommended enclosure volumes or port dimensions should be made using dedicated enclosure- design software. If this type of software is not available to you, ask your authorized Infinity dealer for help.

ENCLOSURE CALCULATIONS AND BUILDING BOXES

Use the recommended box designs on the enclosed data sheet. Choose cabinet dimensions to fit your vehicle, but do not change the enclosure’s volume. Doing so will change the tuning frequency of the enclosure and may adversely affect final performance. If you cannot perform the necessary calculations yourself, please con- tact your authorized Infinity dealer for help.

In addition, there are a number of points you’ll want to keep in mind as you con- struct an enclosure:

1. Use 3/4" (19mm) MDF (medium-density

fiberboard) or marine birch wood to build

an enclosure. Enclosures for 12" and larger

subwoofers, or small subwoofers driven by

high-power amplifiers, should be construct-

ed using 1" (25mm) material.

2. Seal all joints with glue and screws; do

not use nails. We recommend "deck", "zip"

or drywall screws since they have coarse

threads for better grip and don’t require

pre-drilling holes. Once the box has been

tested, seal all interior joints with silicone

caulk.

material inside the box. Rectangular vents can be used as long as the cross-section surface area matches the recommended port-area values in the enclosed data sheet.

5.When using vented boxes, we recom- mend using a subsonic filter (like the DBO™ feature found on Kappa Series power amplifiers) to limit the power sent to the speaker at frequencies below, the enclo- sure’s port tuning frequency, thus limiting the speaker’s excursion.

YOUR CAR AND BASS REPRODUCTION

Depending on the size of the vehicle’s interior listening space, reproduced fre- quencies below 80Hz are boosted by nearly 12dB per octave in the car as frequency decreases. NOTE: This effect, known as the vehicle’s transfer function, plays an impor- tant part in shaping the overall in-car response and is displayed graphically along with freespace response on the enclosed data sheet for your Reference Subwoofer.

3. Depending on the application, fill the

enclosure according to the design you have

chosen from the enclosed data sheet in one

of three ways: zero-percent fill (i.e., no fill),

50-percent fill (i.e., 1"-thick polyfill sheets on

all inside walls except where subwoofer is

mounted), or 100-percent fill (i.e., entire box

is stuffed with loosely packed polyester

fiberfill).

4. Use PVC or ABS pipe for ports. Keep in

mind the openings at either end of the port

must be at least one port diameter away

from any obstructions, including filling