Hi guys, i am lately playing with some metal and the cnc, i thought it would not cut it but it does. although be it with allot of chatter, so Ok for prototyping but i would not dare put it on and get a cofee 🙂
i measured my distortion at different outputs and i wondered if there is a reason why the second order harmonic ,multiplies in percentage compared to the 3th that remained the same or maybe even went down.
The planar is sitting in a tractrix horn, that is far from perfect and gives this nice wiggle in the top end 🙂 but it does add some db's to the low end.
anyhow here are the measurements
First at low volume @ 1 meter Pic 1
Pic 2 at at 60 cm @ 96 dB at 1 meter. (so compensated because the room became a problem)
Pic 3 the contraption
Now i wondered why in the high spl measurement, the 3th order distortion remains under 0.08% from 500 hz and up compared to the rocketing second order. i dont see a correlation to the third harmonic when spl is upped. it just remains low or get even lower. any one have a clue why thats happening and what might cause the second order to sky rocket. although still being under ~0.2% it does make up for almost alllllll the THD, the second order tracks the total harmonic almost 1:1
i measured my distortion at different outputs and i wondered if there is a reason why the second order harmonic ,multiplies in percentage compared to the 3th that remained the same or maybe even went down.
The planar is sitting in a tractrix horn, that is far from perfect and gives this nice wiggle in the top end 🙂 but it does add some db's to the low end.
anyhow here are the measurements
First at low volume @ 1 meter Pic 1
Pic 2 at at 60 cm @ 96 dB at 1 meter. (so compensated because the room became a problem)
Pic 3 the contraption
Now i wondered why in the high spl measurement, the 3th order distortion remains under 0.08% from 500 hz and up compared to the rocketing second order. i dont see a correlation to the third harmonic when spl is upped. it just remains low or get even lower. any one have a clue why thats happening and what might cause the second order to sky rocket. although still being under ~0.2% it does make up for almost alllllll the THD, the second order tracks the total harmonic almost 1:1
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What was the impedance of the ribbon and what amplifier were you using to drive it? Any chance you are seeing the amplifier struggling with a difficult load? You could measure the distortion of the amplifier output to compare.
I know I was getting ~0.1% distortion from my amplifier when driving a 2ohm ribbon.
DIY ribbon dipole tweeter, reductio ad minimum
I know I was getting ~0.1% distortion from my amplifier when driving a 2ohm ribbon.
DIY ribbon dipole tweeter, reductio ad minimum
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