EAW NT29 - Manual (Page 6)

Eastern Acoustic Works One Main Street Whitinsville, MA 01588 tel 800 992 5013 / 508 234 6158 fax 508 234 8251 www.eaw.com
EAW products are continually improved. All specifications are therefore subject to change without notice. Part Number: RD0302 (A) NT29 SPEC December 2005
N T 2 9 S p e c i f i c a t i o n s
group · J
INPUT PANEL
NOTES
TABULAR DATA
1. Measurement/Data Processing Systems: Primary - FChart: proprietary EAW software; Secondary - Brüel & Kjær 2012.
2. Microphone Systems: Earthworks M30; Brüel & Kjær 4133
3. Measurements: Dual channel FFT; length: 32 768 samples; sample rate: 48 kHz; logarithmic sine wave sweep.
4. Measurement System Qualification (includes all uncertainties): SPL: accuracy +/-0.2 dB @ 1 kHz, precision +/-0.5 dB 20 Hz to 20 kHz, resolution 0.05 dB; Frequency: accuracy +/-1 %,
precision +/-0.1 Hz, resolution the larger of 1.5 Hz or 1/48 octave; Time: accuracy +/-10.4 µs, precision +/-0.5 µs, resolution 10.4 µs; Angular: accuracy +/-1°, precision +/-0.5°, resolution 0.5°.
5. Environment: Measurements time-windowed and processed to eliminate room effects, approximating an anechoic environment. Data processed as anechoic or fractional space, as noted.
6. Measurement Distance: 7.46 m. Acoustic responses represent complex summation of the subsystems at 20 m. SPL is referenced to other distances using the Inverse Square Law.
7. Enclosure Orientation: For beamwidth and polar specifications, as shown in Mechanical Specification drawing.
8. Volts/Amperes: Measured rms value of the signal or as noted.
9. Watts: Per audio industry practice, “loudspeaker watts” are calculated as voltage squared divided by rated nominal impedance. Thus, these are not True Watt units of energy as defined by
International Standard.
10. SPL: (Sound Pressure Level) Equivalent to the average level of a signal referenced to 0 dB SPL = 20 microPascals.
11. Subsystem: This lists the transducer(s) and their acoustic loading for each passband. Sub = Subwoofer, LF = Low Frequency, MF = Mid Frequency, HF = High Frequency.
12. Operating Mode: Between system elements, a comma (,) = separate amplifier channels; a slash (/) = single amplifier channel. DSP = Digital Signal Processor.
13 . Operating Range: Range where the processed Frequency Response stays within -10 dB SPL of the power averaged SPL within this range; measured on the geometric axis. Narrow band
dips are excepted.
14. Nominal Beamwidth: Design angle for the -6 dB SPL points, referenced to 0 dB SPL as the highest level.
15. Measured Axial Output Limit: SPL for Pink Noise and an average of musical selections at the Limit and Clip thresholds; measured on the geometric axis, referenced to 1 m.
16. Electrical Performance: Input, DSP (Digital Signal Processing), amplifier, and ac mains characteristics.
17. Controls: Functions that can be adjusted by the operator.
18. Indicators: Operating status indicators.
GRAPHIC DATA
1. Resolution: To remove insignificant fine details, 1/12 octave cepstral smoothing was applied to acoustic frequency responses and 1/3 octave cepstral smoothing was applied to the
beamwidth and directivity data. Other graphs are plotted using raw data.
2. Frequency Response: Variation in acoustic output level with frequency for a constant input signal. normalized to 0 dB SPL.
3. Phase Linearity: The difference in phase between the input signal and acoustic output, with signal processing latency removed.
4. Beamwidth: Average angle for each 1/3 octave frequency band where, starting from the rear of the loudspeaker, the output first reaches -6 dB SPL referenced to 0 dB SPL as the highest
level. This method means the output may drop below -6 dB SPL within the beamwidth angle.
6. Directivity: Directivity Index (DI) and Directivity Factor (Q).
5. Polar Data: Horizontal and vertical polar responses for each 1/3 octave frequency band 100 Hz to 16 kHz or Operating Range.
2-Way, Bi-Amp
AMP
AMP
HF
LF
THRU
IN
INPUT
A / D
LPF
EQ
LIMIT
DELAY
D/A
HPF
EQ
LIMIT
DELAY
INPUT
D/A
A/D
DSP PC BOARD
AMPLIFIER &
POWER SUPPLY
ASS’Y
1000 W @ 4 ohm
500 W @ 4 ohm
SIGNAL DIAGRAM
LEGEND
DSP/EQ: Integral Digital Signal Processing.
HPF: High Pass Filter for crossover.
LPF: Low Pass Filter for crossover.
LIMIT: Driver and Electronic Protection.
LF/MF/HF: Low Frequency / Mid Frequency / High Frequency.
AMP:
Power Amplifier.