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
Attachments
Last edited:
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
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.