Thumbnail for GR Research M-165x CSD Graph - Measurement taken with ARTA and Behringer ECM8000 mic, driver not broken in.
Thumbnail for Vifa XT 25TG 30-04 Impedance/Phase graph - Measurement taken with a Woofer Tester 2, driver not broken in.
Thumbnail for GR Research M-165x Impedance/Phase graph - Measurement taken with a Woofer Tester 2, driver not broken in.
Thumbnail for Vifa XT25 and GR M-165x frequency plot overlay - Measurement taken with both drivers mounted in Parts Express .75cu/ft sealed box, ARTA and Behringer ECM8000 mic, 1/6 octave smoothing. Measured at slightly under 1 meter distance, ignore below 200hz. Amplifier volume was identical for both driver measurements, and overlaid to show relative sensitivities.
Thumbnail for M-165x/XT 25 2-way crossover testing - Yellow = without notch on woofer, Pink = with notch filter. Green line is with notch (volume raised for easier visibility), more baffle step and what looks to be a crossover design ready for assembly and voicing!
Thumbnail for M-165x/XT 25 2-way stereo testing - Just a shot of how I'm doing the testing. Having all the crossover components so easily accessible during testing makes changes VERY easy. In approx 6 hours of testing and listening to music, I've made about 20 small changes, searching for the perfect combination.
Thumbnail for M-165x/XT 25 2-way stereo testing - The speakers setup in stereo, two complete sets of crossovers assembled on the floor with alligator clips. My feline assistant is pre-occupied with butt licking ... he should be running the measurement gear.
Thumbnail for M-165x/XT 25 2-way final response - Both channels measured, the XT25 has always been noted for it's consistency, and that's the case here as well. Also I personally have now tested/measured 8 GR M-165x drivers and have foun them to be extremely consistent as well.
Thumbnail for M-165x/XT 25 2-way Crossover Schematic - Final crossover schematic for the GR Research M-165x/Vifa XT 25TG 30-04 2-way
Thumbnail for M-165x/XT 25 2-way Crossover Picture
Thumbnail for M-165x/XT 25 2-way Crossover Picture
Thumbnail for M-165x/XT 25 2-way Crossover Picture
Thumbnail for M-165x/XT 25 Speaker Response and Reverse Null measurement - Measured response with tweeter wired out of phase (normal operation), and in-phase showing deep suckout and crossover frequency. This shows good phase tracking through the crossover region.
Thumbnail for M-165x/XT 25 testing showing response of different designs - Lets see if I can remember what all these curves are : Yellow = tweeter response obviously Orange = woofer response with notch filter Light Purple = woofer response with no notch or zobel Pink = woofer response with zobel Dark Yellow = combined response with no notch or zobel on woofer Purple = combined response with notch Green = combined response with zobel
Thumbnail for M-165x/XT 25 2-way Final Impedance/Phase - The final impedance/phase measurement of the finished design taken with a Woofer Tester 2. This shows good phase tracking, and an easy load. I'd call this a 6ohm speaker.