No. You disagree with me (and physics).BesPav said:
You now agree with me (and physics). So what do you think? You can't agree with something and its exact opposite.
No. It is the nonlinearity of the speaker impedance which is being measured. Nonlinearity causes distortion.
This is precisely what I have been trying to teach you.
No. Distortion is created by nonlinearity (in the speaker). This distortion is then rendered visible by resistance in the circuit (which will also affect the damping too). Poor damping does not cause nonlinearity and so cannot cause nonlinearity.
Cable capacitance and inductance is small (for speaker cables) and fairly linear, so not a source of distortion.xrk971 said:
Good joints are linear, otherwise most modern technology could not work.
You seem to want to believe that cables cause distortion. Why? Science says no. Technology says no. Careful measurements say no. Why choose to believe the opposite of the truth?
I think that you can’t stop trolling me.
All have already understand, but you’re continue to argue.
Yes.
Read carefully. The observed distortion was caused by interacting between speaker nonlinearity and cable resistance, while latter also makes this visible.
There is a good reason for which at high displacements of the voice coil, this can be true. Many tests have shown that some drivers distort less when current driven (with the drawback that electrical damping is lost and the frequency response needs compensation) and other drivers distort less when voltage driven. If somebody thinks of current driving, he must first check the distortion on each mode.
On large displacements, the B of the Bl decreases. Then the back-EMF falls, the impedance decreases. In voltage driven mode, there is more current in the voice coil and the moving force tends to push it outside of the gap. Albeit rarely discussed, this effect is known since long, it is called driver instability. Avoiding it is the main advantage of driver current driving.
You see above that how physics can be subtle. Note that some great names have investigated driver behavior in current mode.
Hi Valeriy,
I was not courageous enough to read the whole thread but let me bring my 12 cents:
- I hope you are measuring with a differential input connected to the load to avoid especially signal return wire influence,
- in case of considerable impedance of the wires that go to the load, they may decrease damping factor of the amplifier and then distortion rises, because speaker non-linearity, reflected as non-linear speaker current, is more affecting the resulting distortion, please see
Current drive of speakers and speaker distortion
Cables itself have no distortion, it is all about conditions in the complete circuit.
Similar thing happens if you connect headphones to headphone amplifier with higher output impedance, like 50 ohm vs. amp with something like 1 ohm output impedance. You will measure higher distortion in case of the 50 ohm output, because headphone driver non-linear current results in higher voltage distortion across higher impedance. In case of lower output impedance the damping is better and measured voltage distortion is lower.
Last edited:
Hi Pavel,
Those were the "strange" results we started at. Later on, I have identified the problem with the analyzer's input connection - described here:
Correct measurements at the far end of the cable
Finally, I ran a series of tests with the real speaker at the low frequencies, demonstrating non-linearity of the speaker impedance and the fact that the cable with higher Z allows more noticeable distortion at the speaker end (which is practically a divider exercise):
Real speaker spectrums measurement
These measurements are actually in line with the ones presented in your article.
Cheers,
Valery
I would like to propose that, if it were possible, someone would measure a system of this type:
6moons audioreviews: Mr. Fussball’s budget system
The amplifier has no feedback, so there is no influence out there, and the speakers are full-range without crossovers, there's no influence out there either.
But the secondary of the output transformer, connected directly to the speaker coil forms a balanced system, and that's the interesting part. Does this reduce the noise and distortion in relation to a 'normal' connection (feedback + crossovers) or does it have no influence? If it produces any improvement this would be a very interesting type of system.
Thanks in advance
6moons audioreviews: Mr. Fussball’s budget system
The amplifier has no feedback, so there is no influence out there, and the speakers are full-range without crossovers, there's no influence out there either.
But the secondary of the output transformer, connected directly to the speaker coil forms a balanced system, and that's the interesting part. Does this reduce the noise and distortion in relation to a 'normal' connection (feedback + crossovers) or does it have no influence? If it produces any improvement this would be a very interesting type of system.
Thanks in advance
Thank you, i’d not needed, actually doesn’t need and, i’m suppose, will not need such a teacher.
Not one of you, dear teachers, doesn’t ask Valery WHAT, WHERE and HOW he need to measure.
So shut up and stay away, as GB minister of defense says.
Yes, you’re clearly right now.
Cable is linear and it’s a single reason to distortion. It’s resistance hinders secondary current from driver’s coil to be shorted/dumped by/to the low output resistanse of the amplifier.
While speaker is connected to the amp without long/resistive cable there are no distortion.
Open your eyes, exactly cable resistanse being linear nevertheless simultaneously causes distortion and makes it’s visible.
Boring now, thank you for our conversation.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.