LRDDMC Loudspeaker Resistor Drive Distortion Measurement Challenge

Nobody wants to know if you hear distortion.

But

Do you measure distortion?


I thought about what a measurement experiment could look like so that the person measuring can directly experience what they are currently doing and achieving.

Do you have a speaker? Good!

Have you ever measured the frequency response of your speaker? Good!

Can you connect a line directly to a transducer in it (leave out the crossover)? Good!

Find a resistor with 20R! Don't worry about the power performance of this resistor! Just keep explosives, your beautiful toddler, your cat... away! 10 Watts is what i use. That's plenty and certainly a lot more than my speaker can handle.

Complete your usual measurement setup.

Carry out a measurement at a very moderate volume. Only the transducer in the box, directly connected to the amplifier. [1]

Save this measurement to overlay. [1]

Then insert the 20R resistor. In series to the transducer. Carry out a second measurement. Increase the volume to approximately the same sound pressure level. [3]

This is all about distortion. So RTFM until you have two distortion charts.
[4] One connected directly and one with the 20R in series.

If you do not see a difference in D3 ask here for help.


This was done at 0,5 Volts at the transducer:
No need to blast your speaker!

20240107 1 fundamental 0R.png

[1] yellow is the fundamental directly connected (0R)


20240107 2 noise.png

[2] Same setup, just disconnected speaker. Noise...


20240107 3 fundamental 20R green.png

[3]
green is with 20R in series.
yellow is directly connected (from [1])


20240107 4 D3o white 0R D3 red 20R .png

[4]
D3o (white) is directly connected (0R)
D3 (red) is with 20R in series

20240108 Edit 1:
I am extremely disappointed by the fact that no one is taking measurements here on diyAudio. There are only theoretical heroes here who type more or less gross nonsense with their keyboard.

20240108 Edit 2:
User >OllBoll< on diyAudio was the first measuring "it".
https://www.diyaudio.com/community/threads/hypex-ncore.190434/page-384#post-4095122
He was cited on a German forum on
12.09.2023, 16:47
9 years (nine years !) later, because there was nobody on the whole internet measuring "it". Now that
Tenson< joined,
https://www.diyaudio.com/community/...ortion-measurement.402566/page-9#post-7558653
we are 3. Please be the 4th ;-)

20240110 Edit 3:
tmuikku< joined (#40), we are 4. please be the 5th ;-)
 
Last edited:
  • Like
  • Thank You
Reactions: 1 users
AX tech editor
Joined 2002
Paid Member
Coming back to Marcel's point: I would expect to clearly see the speaker resonance with the 20R drive on the freq response.
There's no sign of it, which makes the measurement suspect.
Not against measurments - on the contrary, without measurements you know nothing.
I am always measuring my projects.
But this is very strange. Or did you do some kind of pre-correction?

Jan
 
Coming back to Marcel's point: I would expect to clearly see the speaker resonance with the 20R drive on the freq response.
There's no sign of it, which makes the measurement suspect.
Plot starts at 100Hz, resonance is probably below 30Hz. With 20R the increase in Q may be moderate. I think we see signs of response starting to rise at 100Hz. Lot's of guesswork.
Rather than providing clarification to our questions the OP chose to be snarky and condescending in his usual style.

I fear this thread is doomed.
 
AX tech editor
Joined 2002
Paid Member
I don't really understand why I should repeat this measurement.
Do you need confirmation?
It is anyway hard to replicate your measurement because there is no information about what exactly you did.
No measurement setup, connections, used amplifier/speaker, and as noted the results you gave bring up more questions than it answers.
You refuse to answer reasonable questions, so I don't think people will drop what they are doing to do - what exactly?

Jan