Lowell 12Q250 Datasheet
Spec No. 1450 [REV. 11.03.16] Page 1/3
Model No.
12Q250: 12" 250W Coaxial Compression Driver
The 12Q250 is a premium, high-delity performance driver with a robust
motor structure engineered for high ceiling, high energy applications like
convention centers, ballrooms, athletic facilities, airport terminals, and
entertainment venues.
FEATURES
• Description: Large-format high frequency compression driver with
38.8 oz. magnet and 1.75 inch voice coil for an exceptional combination
of power handling and efciency. Low frequency driver with 77.6 oz.
magnet and 3.0 in. aluminum voice coil. Built-in crossover network
with fourth-order high-pass and third order low-pass lter for proper
frequency division between the two drivers.
• Frame: Cast aluminum frame with black corrosion-resistant nish.
• Power Rating: 250W RMS
• Frequency Response: 60Hz–19.2kHz (+6dB), 45Hz–20kHz (+7.2dB)
• Dispersion Angle: 90 degrees conical @2kHz octave (-6dB).
• Average Sensitivity: 100.3dB (SPL@1W/1M)
• Origin: Made in Europe to Lowell's specications to meet or exceed
all applicable EIA standards.
A&E SPECIFICATIONS
The 12 inch driver shall be Lowell Model 12Q250 which shall be of the
coaxial compression type having electrically independent high and low
frequency transducers. The low frequency section shall have a 12 in.
diameter cone and the high frequency section shall have a 1.75 in. large
format compression driver. A built-in electrical crossover network shall be
employed to accomplish the proper frequency division between the two
drivers. The crossover shall be at 2.2 kHz with fourth order high-pass lter
and third order low-pass lter. The driver shall be capable of producing
uniform audible frequency response over the range 60Hz–19.2kHz (+6dB),
45Hz–20kHz (+7.2dB) with dispersion angle of 90 degrees conical @ 2kHz
octave.
Average sensitivity shall measure 100.3dB (SPL at 1W/1M). Power rating
shall be 250 watts RMS. The low frequency voice coil shall have a 3
in. diameter and shall operate in a magnetic eld derived from a ferrite
magnet with 77.6 oz. nominal weight. The high frequency voice coil shall
have a 1.75 in. diameter and operate in a magnetic eld derived from a
ferrite magnet with 38.8 oz. nominal weight. Voice coil impedance shall be
8ohms. The driver shall have a round, structurally reinforced cast aluminum
frame with 12.3 in. overall diameter and eight holes equally spaced at 45
degrees on 11.6 inch diameter mounting bolt circle. Overall depth shall not
exceed 7.6 in. External metal woofer parts shall be painted or of materials
that resist rust and corrosion.
Lowell makes every effort to provide accurate information while reserving the right to change specications and/or improve manufacturing methods without notication.
©2016 Lowell Manufacturing Company, 100 Integram Dr., Pacic MO 63069 | 800.325.9660 | www.lowellmfg.com
Spec No. 1450 [REV. 11.03.16] Page 2/3
DRIVER SPECIFICATIONS
PERFORMANCE:
Power Rating ......................... 250 watts measured per EIA Standard RS-426B
Sensitivity ............................... 100.3dB Average SPL (measured 2.83V @1m)
124.3dB Maximum SPL (calculated based on power rating and measured sensitivity)
Impedance .............................. Driver Nominal Impedance: 8 ohms
Driver Minimum Impedance: 7.0 ohms @967Hz
Driver Measured Impedance: 7.1 ohms @1kHz
Frequency Response ............. 60Hz–19.2kHz (+6dB), 45Hz–20kHz (+7.2dB)
Crossover Frequency ............ 2.2kHz, fourth order high-pass lter, third order low-pass lter
Dispersion Angle ................... 90 degrees conical @2kHz octave (-6dB)
PHYSICAL – WOOFER:
Cone ....................................... Paper cone with plasticized cloth surround
Magnet ................................... 77.6 oz. (2.2 kg) ferrite
Voice Coil ................................ 3.0 in. (76.20mm) aluminum wire
Top Plate ................................. 0.28 in. (7mm) thick
Terminals ................................ Quick disconnect type, spade lugs
Outside Diameter ................... 12.3 in. (312mm)
PHYSICAL – HIGH FREQUENCY DRIVER:
Type ........................................ Compression driver
Magnet ................................... 38.8 oz. (1.1 kg) ferrite
Voice Coil ................................ 1.75 in. (44mm) edgewound aluminum wire / 1.75 in. polyester cone
Top Plate ................................. 0.34 in. (8.6mm) thick
Outside Diameter ................... 5.3 in. (134mm)
MECHANICAL:
Basket ..................................... Cast aluminum
Mounting Bolt Circle ............... 11.6 in. (295mm) with 8 holes equally spaced at 45 degrees (EIA RS-278-B)
Cutout Diameter .................... 10.95 in. (278mm)
Mounting Depth ..................... 7.6 in. (193mm)
Net Weight ............................... 26.7 lbs. (12.1 kg)
THIELE-SMALL PARAMETERS:
Pe ................. 250W Qts ......................0.22 BL .............................20.1 Tm Sd .......................85.3 in.2 (550cm2)
Fs ................. 45Hz Qes .....................0.22 Efciency, h ...............4% Mms .................... 0.051 kg
Xmax ............... 0.20 in. (5.1mm) Qms ....................14.95 Vas ............................101.21 liters, 6175.5 cu.in. Cms ....................0.237 uM/N
Re ................. 6.25 ohms
SCOPE of PERFORMANCE and POWER TESTS
Lowell drivers and loudspeaker systems are tested to provide speciers and contractors
with data that reects the performance of production products. Testing equipment
includes the GoldLine TEF-20 analyzer (for performance measurements) and the LinearX
LMS measurement system (for Thiele-Small Parameters).
Power Rating is tested based on EIA Standard RS-426B.
Frequency Response data is provided which is the measured frequency response
range (dened by +6dB) which is useful in predictive engineering calculations.
Sensitivity (SPL) data is presented in two ways:
1. Log Average SPL is a computer calculated log average of the SPL measured at
1 meter with 1 watt input over the stated frequency response range.
2. Maximum SPL is calculated based on the measured log average SPL and the
8ohm power rating of the speaker. Maximum SPL for speakers that do not include
an 8ohm input, is calculated based on the measured log average SPL and the
highest transformer power tap.
Dispersion Angle is dened as the angle of coverage that is no more than 6dB down
from the on-axis value averaged over the 2000Hz octave band. Since speech intelligibility
is very dependent upon the 2000Hz octave, this specication is quite useful in designing
speech reinforcement systems that provide even coverage and speech intelligibility.
Thiele-Small Parameters for raw drivers are measured using the LinearX LMS
measurement system. These parameters are useful in determining the optimum type
and size of enclosure for a specic driver.
Lowell makes every effort to provide accurate information while reserving the right to change specications and/or improve manufacturing methods without notication.
©2016 Lowell Manufacturing Company, 100 Integram Dr., Pacic MO 63069 | 800.325.9660 | www.lowellmfg.com
Polar Data is presented for the averaged one octave band surrounding the center
frequencies of 1000Hz, 2000Hz, 4000Hz, and 8000Hz. Radial polar response curves
show the relative change in sound pressure level as one moves from directly onaxis to an increasingly off-axis listening position. Since coaxial speaker drivers are
symmetrical in the vertical and horizontal directions, only one set of polar plots will
be presented for coaxial drivers and speaker systems incorporating coaxial drivers.
Impedance Data may be represented in four different ways depending on the
particular model:
1. Nominal Impedance is the generally accepted impedance value for use in
making comparisons with competitive products.
2. Impedance Curve is a graphical representation of the 8ohm driver impedance
measured in the lab and gives the impedance of the device over the audio
frequency range.
3. Minimum Impedance is the lowest impedance measurement of the 8ohm driver
at a frequency within the specied frequency response range of the speaker.
4. Impedance Measured at 1kHz is the reading expected to be measured by a
technician in the eld using a typical industry 1kHz impedance meter.
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