JBL P81 Loudspeaker Overview, Tweeter, High-Frequency Tilt Control, Woofer, Listener Axis Control

LOUDSPEAKER OVERVIEW

	P81/P941 DRIVER COMPLEMENT					3. High-Frequency Level (dB) Control
	The numbers in Figure 3 correspond to					Provides a shift in the output level of
	the numbered items in this section.					the tweeter or overall high-frequency
	1. Tweeter					response (active above approximately
						2.5kHz). The options are –1dB, 0dB
	• 1-inch (25mm) titanium dome
						and +1dB.
	• Underhung with copper-clad alu-					4. High-Frequency Tilt Control
	minum wire for low distortion					Adds a ”tilt“ to the high-frequency
	• Ferrofluid for high-power handling
						response. The tilt will become active
	with reduced compression					above approximately 8kHz (depart
	2. Woofer
						from nominally flat response) and will
	• 7-1/2-inch (191mm)/9-inch (229mm)					increase to 3dB – 4dB at 20kHz. This
	cones constructed with Organic					will offer an improved high-frequency
						response for installations where the
	Ceramic Composite cone material for
						primary listening position is located
	low distortion
						significantly off the tweeter axis (for an
	• True pistonic operation for increased
						effect almost like adding ”toe in“ towards
	freedom from coloration					the listening position). The added high-
	• Symmetrical Field Geometry (SFG™)
						frequency contour helps to offset per-
	design for low overall distortion					ceived reduction of high-frequency
	• Aluminum ring for flux stabilization					response for off-axis listeners due to
	greatly reduces distortion at low fre-					the increase in directivity of the system
						(tweeter beaming) above 8kHz.
	quencies
	• Butyl rubber surround for large, linear					5. Listener Axis Control
	excursion capabilities					All loudspeakers sound best when the
	• Carbon composite aluminum (CCA)					listener is positioned at optimal angles
	flatwire voice coil wound on a 1-1/2-					relative to the speaker placement. This
						is a fixed angle for most loudspeakers,
	inch (38mm) fiberglass bobbin for low
						but the P81 and P941 provide compen-
	mass and higher power handling
						sation for much greater placement
	• Vented center pole for improved heat
						flexibility. The listener axis control,
	dissipation and low compression					used in conjunction with the placement
						of the speaker, can obtain excellent
						results in a very wide range of circum-
					£	stances. This control optimizes system
				–1		response for installations in which the
		High Frequency Level (dB)		+1
				0		listening positions are lower than,
¡					¢
		Low Frequency	High Frequency Tilt	0		higher than, or directly level with the
§	on					tweeter. This switch will be active
			Listener Axis	on axis
	off Compensation
		Boundary			∞in the network transition regions
						between the woofer and tweeter
						(in the P81) and the midrange and
™						tweeter (in the P941).
						• Select the “high” (up arrow) setting
						if the speaker is mounted so that the
						listener is at tweeter level or above.
						• Select the “on axis” setting if the
						listener position is located directly
						on axis with the tweeter level.
	The numbers in Figure 3 correspond to the					• Select the “low” (down arrow) set-
	numbered items in the Driver Complement					ting if the speaker is mounted so that
	section.					the listener is below tweeter level.
	Figure 3: P81 Speaker (Front View)					NOTE: In some circumstances, such
						as when the speaker is to be mounted
						high on the wall towards the ceiling, it

may be desired to invert the speaker in order to place the tweeter axis closer to the listener’s ear level. The Listener Axis Control will also optimize these

inverted speaker installations. Refer to the Notes on page 9 and the Optimizing Performance (page 12) section for addi- tional information.

6.Low-Frequency Boundary Compensation Control

Compensates for less-than-ideal speaker placement near adjacent walls or boundaries.

•Select the “off” setting if the speaker is mounted at least 4 feet away from adjacent walls or boundaries.

•Select the “on” position if the speaker is less than 4 feet from one (or possibly two) or more adjacent walls or boundaries. In the ”on“ position, system output is reduced below approximately 400Hz to offset the increased low-frequency support, due to the boundary.

NOTE: Refer to the Optimizing Performance section on page 12 for more information about the front-panel controls.

		High Frequency Level (dB)	+1
			0
			–1
		High Frequency Tilt	0
on	Low Frequency	Listener Axis
	Boundary		on axis
off
	Compensation

The numbers in Figure 4 correspond to the numbered items in the Driver Complement section.

Figure 4: P941 Speaker (Front View)

7. Midrange (P941 Only)

•3-1/2-inch (89mm) cone constructed with Organic Ceramic Composite material

•Die-cast basket to eliminate col- oration from resonances

•True pistonic operation for increased freedom from coloration

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