Blaupunkt VXS 12 Notes On Installation And Operation page 2

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Thanks for choosing Velocity!
Congratulations on your purchase of your new Velocity product! We have invested tremendous effort
in the de-sign process of the new Velocity subwoofer Referencseries, in order to achieve superior
musical performance.
For maximum performance and reliability we highly recommend that your new Velocity subwoofers
be installed by an authorised Velocity dealer. By using our Velocity line component speakers and
amplifiers you can be as-sured of making the best out of your high-quality audio hi-fi system without
spoiling the sound by using com-ponents of inferior quality.
For additional information on the Velocity Product Line (technical data, user notes and soon also a
simulation programme for subwoofer housings) visit our Internet site at: http://www.velocity.de.
Safety precautions
Before starting to mount your speakers, please read carefully the instructions on installation and
connection.
Disconnect the negative terminal of the battery before carrying out installation and connection work.
Observe the vehicle manufacturer's safety instructions (regarding airbags, alarm systems, trip
computers, vehicle immobilisers).
When drilling holes, take care to avoid damage to vehicle components (battery, cables, fuse boxes).
Do not mount the subwoofer onto flexible rear decks (hatchback vehicles) or anywhere where they may
fall for-ward.
SUBWOOFER ENCLOSURE TYPES
Sound is created by the movement of the woofer
cone back and forth. If a woofer cone moves
forward creating a positive pressure wave, this
same motion creates a negative pressure at the
back of the woofer. If these two waves combine
due to the lack of a wall separating the front of the
speaker sound from the back, the output from
the woofer is effectively cancelled thus substan-
tially reducing the bass output of the speaker.
This wall is absolutely necessary and is referred
to as an acoustical "baffle". It can be accom-
plished using a box of some kind or simply the
rear package shelf of an automobile to isolate
the front and back waves of the speaker.
COMMON ENCLOSURE TYPES
In the car audio world there are five types of subwoofer enclosures commonly used: INFINITE
BAFFLE, SEALED BOX (closed box), VENTED BOX (bass reflex), SINGLE-VENTED BANDPASS
(often incorrectly referred to as "5th" order), DUAL-VENTED BANDPASS (often incorrectly referred
to as "7th" order). No single design is superior because each has its own compromise in performance,
power handling and design complexity. The bandpass name implies a "built-in" acoustical response
which has a natural highpass response (30 Hz for example) but also a lowpass response suppressing
high frequencies (e.g., > 80 Hz).
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FRAME
FRONT PLATE
YOKE
VENT
VOICE COIL
MAGNET
SPIDER
SURROUND
CONE
DUST CAP