Parallel Sixth Order-Bandpass Enclosure

The most common type of sixth order enclosure where both vents or ports fire outside the enclosure.

Parallel Wiring

A circuit in which two or more devices are connected to the same source of voltage, sharing a common positive and negative point, so that each device receives the full applied voltage.

Parametric EQ

A multi-band equalizer enabeling control of at least three essential "parameters" of the internal bandpass filter sections. These parameters being: amplitude, center frequency and bandwidth. This allows the user to not only control the amplitude of each band, but also to shift the center frequency and to widen or narrow the width or coverage of the affected section of the aural spectrum. Regulation is done by either rotary and slide controls. Other types of parametric equalizers exist which allow control of center frequency, but not bandwidth. For rotary control units, the most common term is quasi-parametric. For units with slide controls the popular term is paragraphic. The frequency control may be continuously variable or switch selectable in steps.

Passive Component

In a crossover system, a non-powered component used to separate an audio signal into a specified frequency band before it goes to a particular amplifier or driver. A passive device usually presents some loss (expressed in decibels) to a system.

Passive Radiator

Often called a "drone cone". A speaker with no motor assembly that resonates in response to a driven speaker in an enclosure. Passive radiators act very much like a vent or port in a speaker.

Passive Repeater Antenna

A non-permanently installed, glass-mount antenna that is without physical connection to the cellular telephone.

Pass Band

The band of frequencies that a bandpass crossover or bandpass speaker enclosure will allow to pass.

Pe

The maximum continuous (RMS) power-handling capability of a speaker.

Peak

An emphasis over a frequency range not greater than one octave.

Peak Input Power

The amount of power a voice coil can withstand for short periods of time.

Peak Power Handling

Peak power handling refers to the amount of power a speaker is estimated to handle during a brief high-intensity musical burst. Since this can vary with both frequency and amplitude, it is a much less accurate way to judge speaker durability and performance than RMS.

PEI Film

A plastic-based polymer (Polyetherimide) used primarily for tweeters and midrange cones offering high resistance against harsh environmental extremes, superior rigidity, damping and resistance against harsh environmental conditions.

Period

The amount of time required for a single cycle of a sound wave.

Permalloy Tape Head

A cassette tape head constructed of permalloy, an alloy made primarily of nickel and iron, used for its superior high resistance and permeability, offering superior frequency response at a low cost.

Phase

The timing of a sound or electrical wave. Phase is measured in degrees, from 0 to 360. 180 degrees would be perfectly out of phase and often causes signal cancellation in lower frequencies.

Phase Delay

A phase-shifted sine wave appears displaced in time from the input waveform. This displacement is called phase delay.

Phase Shift

Frequency interaction in the crossover region of passive crossovers which can cause some frequencies to be delayed with respect to other frequencies.

Piezo

The name usually given to Piezo electric drivers. This type of driver has no voice coil or magnetic assembly. Instead, Piezo electric material expands and contracts when voltage is applied. The material vibrates and either radiates sound directly, or drives a diaphragm. They can only be used effectively on high frequencies.

Piezoelectric Driver

This is among the most robust and least expensive alternative drivers for the high frequency reproduction. The material used in the Piezoelectric Driver is a piezoelectric polymer first developed in the early 1960's. This piezoelectric polymer is a plastic-like material that, unlike a crystal, can be made into thin sheets and fashioned into a great variety of shapes. Its transient and high frequency response is very good because the moving mass is negligible. The driver operates by bending the lattices in the crystalline structure of the piezoelectric polymer film. The Piezoelectric Driver is inappropriate for low frequency applications, as it is incapable of large air displacements. This high frequency transducer is very uniform in response from approximately 2 kHz to 20 kHz. It typically is used in many car stereo enclosures and other compact space environments.

Piezo Sensors

A type of shock or impact sensor that utilizes the properties of the Piezo electric effect inherent in some materials. A Piezo Sensor typically uses a Piezo electric element to sense impacts or vibrations applied to the vehicle.

Pin Switch

A simple spring-loaded mechanical switch used in many different vehicles designed to turn on interior lights when doors are opened. Pinswitches are also used in the installation of most security systems in the hood or trunk/hatch as a means of triggering the system should these points be opened.

Polarity

In electricity, refers to the condition of being either positive or negative.

Polarity Reversal

A DPDT (Double Pole Double Throw) switch connected between a pair of DC input terminals so that the polarity of a pair of output terminals can be reversed or switched.

Pole Piece

The metal pole attached to the magnet structure in a speaker's motor assembly that is surrounded by the voice coil, forming the inside wall of the gap.

Poly-tex

Textured polypropylene speaker cones, proprietary to JBL's GTO line of mobile audio speakers. The textured surface helps to break up harmonic resonances that travel along the cone surface, improving midrange response.

Polycarbonate

A polymer based plastic material offering superior resistance against resonance.

Polypropylene

A plastic based material used primarily for speaker cones due to its rigidity, damping and resistance against harsh environmental conditions.

Port

An opening, usually a tube, in an enclosure, through which sound is permitted to pass.

Ported Enclosure

Any enclosure design with ports. In such designs the internal pressure wave is processed to be used either solely, or in conjunction with the woofer front wave in order to produce sound. A port can be a simple opening, a tube or a Passive Radiator.

Port Diameter

The measurement across the port opening. Measured as internal diameter (not outer diameter).

Port Length

The measurement of the length of the port.

Positive LCD

A liquid crystal display employing a lit backfield with dark elements. This results in a primarily colored display.

Positive Lead

The lead or line connected to the positive terminal of a current, voltage, or power source.

Potentiometer

A variable resistor made with either carbon or wire wound material which attenuates a signal.

A three-terminal variable resistor. Two terminals connect to the ends of a flat resistor, while the third terminal is attached to a moveable contact that interfaces with the resistive element. The moveable terminal, or slider, is capable of being positioned from one end of the element to the other.

Power

The amount of energy (in joules) that a device delivers or consumes divided by the time (in seconds) that the device is operating.

Powerstat Baskets

This is a composite basket material that provides a rigid, non-resonant platform, which ensures optimum clarity and long-term reliability. An additional benefit is that since it is a non-metallic material, all energy is focused at the voice coils gap, thus increasing speaker efficiency.

Power Handling-RMS

A rating of a Driver's ability in optimum conditions to handle a specified amount of audio power (electrical current power) on a constant basis, without damage. This is generally considered to be a conservative and reliable figure to use in judging what types of amplifier power will be most successful with a particular speaker design.

Power Line Noise

A varying AC ripple that is found riding on a DC voltage. It is recognized by a whining that varies with engine speed.

Power PMP Cones

Injection-molded PolyMethlyPentene woofer cones used on JBL's Competition Series GTX Multi-element speakers. PMP is much lighter and stiffer than either polypropylene or paper, resulting in excellent transient and bass response. PMP's superior damping characteristics also dramatically improve midrange clarity.

Pre-Amp

A circuit unit which takes a small signal and amplifies it sufficiently to be fed into the power amplifier for further amplification. A pre-amp includes all of the controls for regulating tone, volume, and channel balance.

Preamp Output

Typically found on headunits, a preamp output provides low level, high quality audio signal for use with external amplifiers.

Preset

A collection of system settings stored in a memory that is virtually instantly recallable, typically at the touch of a button.

Primary

The input side of a transformer.

Programming Adapter

A device used for programming cellular telephones that allows the telephone to be programmed only when the device is attached.

Program Bank

A Custom File feature that allows the user to flag the tracks on a disc, indicating whether they should be played or skipped.

Program Play

A Custom File feature that allows the user to define a sequence of 12 tracks, in a specific order, for customized playback. Up to two banks of 12 track sequences can be recalled, for up to 24 tracks total.

Progressive Spider

Provides better control at excursion limits than a linear spider.

PSTN

In cellular, refers to the Public Switch Telephone Network.

Pure Titanium Dome Tweeters

JBL uses pure titanium domes in high-end speakers. Titanium is extremely light and stiff, making it an excellent choice for making tweeters.

PVS

Positive Verification System - Part of the MTSO ( Mobile Telephone Switching Office ) in cellular systems that tries to insure that any invalid mobile numbers will not be allowed to make calls.