Alpair 10 MLTL

IMG_0986.JPG
Enclosure
Crossover
Measurements
Summary

Enclosure

Original design by Jim Griffin: Alpair10MLTLDrawing.pdf

New drawing: Griffin-A10-MLTL-030611.pdf

My enclosures are 22 mm MDF.


Crossover

Parametric equalizer:

878 Hz, -2.1 dB, Q=0.8
3.93 kHz, +1.9 dB, Q=3.2
6.96 kHz, -5.0 dB, Q=7.1
8.50 kHz, +3.0 dB, Q=7.1
10.3 kHz, -2.8 dB, Q=10

Frequency response of active filter
Alpair10-MLTL_active_filter_gain.png

Filter is optional. The driver is usable without EQ, but better as equalized.


Measurements

Frequency response

Off-axis response, not equalized
- measuring distance 70 cm
- 0-90º, steps 15º
- time window 7 ms, smoothing 1/12 oct.
Alpair10-MLTL_FR_70cm_0-90deg_7ms_1p12oct.png

Off-axis response, equalized
- measuring distance 70 cm
- 0-90º, steps 15º
- time window 7 ms, smoothing 1/12 oct.
Alpair10-MLTL_FR_70cm_0-90deg_7ms_1p12oct_EQd.png

Average 0-360º horizontal red, on-axis green, not equalized
- measuring distance 70 cm
- time window 7 ms, smoothing 1/12 oct.
Alpair10-MLTL_FR_70cm_0+360deg-avg_7ms_1p12oct.png

Power average 0-360º horizontal red, on-axis green, equalized
- measuring distance 70 cm
- time window 7 ms, smoothing 1/12 oct.
Alpair10-MLTL_FR_70cm_0+360deg-avg_7ms_1p12oct_EQd.png

Frequency response, equalized
- above 300 Hz: at 44 cm on-axis, time window 10 ms, smoothing 1/12 oct.
- below 300 Hz: near field measurement of cone
- port signal attenuated ~7.2 dB (10*log(Av/Sd))
Alpair10-MLTL_FR_near+44cm_cone+port_1000+10ms_1p12oct.png

Impedance response

Alpair10-MLTL_ZR.png


Summary

Do not punish these frail drivers too hard.

IMG_0987.JPG

Created 13.10.2011
Updated 14.10.2011