Adire Audio Extremis 6.8 Owners manual

ADIRE AUDIO® EXTREMIS 6.8™ MIDWOOFER DATA SHEET

30–5000 Hz

0.13 mH

100W RMS

9.0 N/A

40mm

1.2 mm/N

26mm p-p

33.2 L

2.5 kg

.332

The Extremis 6.8 is a high performance
midwoofer with a cast aluminum frame,
suitable for use in mid-sized ported and
sealed cabinets. It has an exponentially
flared polypropylene cone, concave/flat
polypropylene dustcap, rubber surround

A: 176.5mm / 6.95”
B: 147.0mm / 5.79”
C: 98.4mm / 3.88”
D: 44.5mm / 1.75”
E: 70.0mm / 2.76”
F: 90.5mm / 3.63”

for excellent cone termination.

The driver has an aluminum former with a 4 layer copper wound voice coil for high
power handling. A progressive spider with flat landing attachment is used to ensure
linear suspension operation. The motor uses a neodymium magnet mounted on the
pole to create an extremely compact, inherently video shielded motor structure.

The motor uses our patent-pending XBL2™ motor for extreme linearity over the entire
range of motion. This motor yield a very high motor force factor of 9 Newtons per
Ampere, and maintains over 90% of its peak force over the center 20mm of excursion.
Combined with a linear excursion rating of 13mm one way this motor yields the
highest level of low distortion stroke available in any 6.5”/7” woofer on the market
today.

The flat progressive spider and soft rubber surround combine to yield an extremely
linear suspension as well. Suspension compliance has less than a 25% change over the
center 20mm of excursion, and provides a full 26mm of peak to peak throw capability
to equal that of the motor.

Inductance nonlinearities are kept to a minimum by the use of a full copper sleeve on
the pole. This sleeve is a full 1mm thick copper ring that extends 9mm beyond the top
plate. The result is a very low inductance of 0.13 mH, and inductance that does not
change by more than 15% over the entire usable range of throw.

Nominal Impedance: 8 Ohms DC Resistance: 7.02 Ohms
Usable Bandwidth:
Rated Power:
Peak Power: 300W Resonant Frequency: 30 Hz
Rated Efficiency: 86 dB Moving Mass: 23.3 g
VC Diameter:
Linear Travel:
Maximum Travel: 26mm p-p Qms: 2.54
Cone Area: 140 cm2Qes: .383
Driver Weight:

Inductance:
BL:

Compliance:
Vas:

Qts:

RECOMMENDED PORTED BOX: 21 liters tuned to 33 Hz

RECOMMENDED SEALED BOX: 9.5 liters with 100% stuffing

SUITABLE FOR DIPOLE AND TRANSMISSION LINE USE

Copyright © 2004 Adire Audio®. All Rights Reserved. XBL2™ and Extremis 6.8™ are Trademarks of Adire Audio®. See www.adireaudio.com for more details.