Electromagnetic Interference in Speaker Cables? (video)

[Cbdb2]

View attachment 115889

All the current that is inductively coupled has to flow trough the speaker since there is no other current part.

So this coupled current source has no output impedance and is perfect. ie. it will put out infinite voltage if I remove the load from the wire? Draw a complete circuit model with real sources and do the math.

 

[Lambda]

So this coupled current source has no output impedance and is perfect. ie. it will put out infinite voltage if I remove the load from the wire? Draw a complete circuit model with real sources and do the math.

So this coupled current source

its a voltage source.

has no output impedance and is perfect

I don't know but i have the feeling the jagged lines in circuit diagram has something to do with impedance...

it will put out infinite voltage if I remove the load from the wire?

its a voltage source, and there is a current limiting resistor.
but even if not ther is still the inductance with its impedance...

Draw a complete circuit model with real sources and do the math.

There is one in its simplified form and you don't even seem to understand that very basic concepts.

 

[Cbdb2]

This is about induction. Current in one cable inducing CURRENT in the other one. That would make it a current source.

 

[Lambda]

Sure you must be right an inductor in an changing magnate field must be a ideal Current source

ie. it will put out infinite voltage if I remove the load from the wire?

Its not like the rate of change has an influence on the voltage

 

[celroid]

What about this video where he puts a charger next to a normal cable and an xlr cable and there's an audible noise in the normal cable? This seems legit to me.

 

[Lambda]

What about this video where he puts a charger next to a normal cable and an xlr cable and there's an audible noise in the normal cable? This seems legit to me.

It is legit.
The question is if it meters.
A microphone signal is heavenly amplified therefore the interference effect is also amplified.
Without amplification the interference signal is normally to weak to be heard.

 

[Chester]

Hi all

I’m experiencing something, related to this topic and I would appreciate any opinions/thoughts on things I could try to resolve it.

I have a Purifi amp going to F208s. Due to placement I need to run 7m speaker cables. This leads to hiss from the tweeters. 2m cables, there is no hiss. The long cables are not running near anything I would consider a problem, just the edge of a standard wall, nothing of significance on the other side either.

Speaker cable is 10/12awg (I can’t remember exactly, but plenty thick enough) 99.99999% OFC, your usual fare. I think it’s German made (DCSk?)

Any idea what’s going on here?

Thanks in advance.

 

[AndreaT]

Hi all

I’m experiencing something, related to this topic and I would appreciate any opinions/thoughts on things I could try to resolve it.

I have a Purifi amp going to F208s. Due to placement I need to run 7m speaker cables. This leads to hiss from the tweeters. 2m cables, there is no hiss. The long cables are not running near anything I would consider a problem, just the edge of a standard wall, nothing of significance on the other side either.

Speaker cable is 10/12awg (I can’t remember exactly, but plenty thick enough) 99.99999% OFC, your usual fare. I think it’s German made (DCSk?)

Any idea what’s going on here?

Thanks in advance.

It might be related what I experienced with the SMSL A300: it works perfectly on all my speakers xcept one: the Overnight Sensation speaker on the right channel, where it makes clicking sounds at any volume level and with any input selected. It is another Class D amp based on Infineon chip. The same speaker works perfectly on all my other amps. I wonder if a critical combination of cable/crossover brings the Infineon chip to its knees.

 

[Teeter]

@Chester , May I suggest using 2 conductor, twisted pair, stranded wire, used in communications. And if shielded, the better. 7meters is only 23 feet for example, and 16 ga is good to 50 feet, for all practical purposes. Again, look for stranded, 2 cond, TWISTED pair wire/cable. Good luck with your speaker wire. O, Yes, 99% copper wire.

 

[TurbulentCalm]

My wife and I have undergone a blind AB testing (the guy swapped out the interconnects without our knowledge) and detected audible differences from a change in inter-connects.

You would want to make sure that nothing else was altered when he swaps the cables.

(I’m guessing this was being done at a store)

I’ve heard about cable salesman altering volume and other settings when changing cables, to gull listeners into believing the cables made a difference.

Really it would have been better in such a situation for you and then your wife to change the cables, just to rule out this possibility.

Even then the salesman could have a hidden switch.

Honestly the only way to be sure is to have a trusted friend change cables on your own system, in your own home.

There is too much money involved in these cables to trust salesman.

 

[phoenixsong]

I'm wondering... Since the F208 has 4 cable binding posts per tower, can starquad cables be properly used with them?

 

[tomtoo]

Hi all

I’m experiencing something, related to this topic and I would appreciate any opinions/thoughts on things I could try to resolve it.

I have a Purifi amp going to F208s. Due to placement I need to run 7m speaker cables. This leads to hiss from the tweeters. 2m cables, there is no hiss. The long cables are not running near anything I would consider a problem, just the edge of a standard wall, nothing of significance on the other side either.

Speaker cable is 10/12awg (I can’t remember exactly, but plenty thick enough) 99.99999% OFC, your usual fare. I think it’s German made (DCSk?)

Any idea what’s going on here?

Thanks in advance.

Thats so unusal, counterintuitive, and hard to have a easy technical explanation, that i would start a extra thread.

 

[TurbulentCalm]

Nothing. Nothing at all.

Did you experience a vale being lifted when listing to music in that gym?

 

[xarkkon]

You would want to make sure that nothing else was altered when he swaps the cables.

(I’m guessing this was being done at a store)

I’ve heard about cable salesman altering volume and other settings when changing cables, to gull listeners into believing the cables made a difference.

Really it would have been better in such a situation for you and then your wife to change the cables, just to rule out this possibility.

Even then the salesman could have a hidden switch.

Honestly the only way to be sure is to have a trusted friend change cables on your own system, in your own home.

There is too much money involved in these cables to trust salesman.

Good points indeed. Had alluded in my post that the change could very well have been intentionally engineered in through "other" means as well for marketing as something better. I'll try again at home one day when I do have the gear!

 

[Helicopter]

I'm wondering... Since the F208 has 4 cable binding posts per tower, can starquad cables be properly used with them?

Yes you could biwire like that. You could also join the conductors in pairs and keep the jumpers on the speaker jacks, Pretty similar if you don't bi-wire (still reasonably similar) or bi-amp.

 

[audio2design]

Why?

Because noise induced in speaker cables does not get amplified.

.

Late to the party (thread) but this statement is not fully accurate. The real answer is architecture and frequency dependent. High frequencies on the speaker cable can inject back through the feedback network and be amplified. If that injection is AM modulated high frequencies that could theoretically be picked up , be amplified, and be audible. Unlikely but possible.


P.s. wrt your cell phone and cheap powered speaker comment, that is from back in the TDMA days. The injected signal is high frequency RF that is time devision multiplexed which is essentially an amplitude envelope that is demodulated in the cheap powered speaker and becomes audible frequencies.

 

[audio2design]

Noise on speaker cables can be amplified -- it depends upon the feedback circuit and output stage topology. But, at power-line frequencies of 50~120 Hz or so, feedback is working just fine and the effective output impedance is so small as to preclude any but pathological cases rarely seen in the home. In the pro world, it happens more often than we'd like, typically smaller venues that run a single small trench through which power, mic, line, and speaker cables get bundled together from back to front of the house (venue, building). The coupling mechanism is primarily inductive, not capacitive, as pointed out above.

At RF, the output impedance is usually high, and you hope the amp designer has included proper RFI suppression at the output and/or feedback circuit to prevent RFI demodulation and amplification back to the speakers.

IME/IMO - Don

.
I should have read your post before replying . Even with filtering of the input AC, the issue is not the primary mains frequencies but events that happen at the primary mains frequency (or usually 2x) like lamp dimmers or current peaks from linear supplies. These have much higher frequency components but can demodulate back to 2x line rate (and multiples). However as you noted that's more a pro audio issue were mains and low level signals are ran close together.


Cable vendors like to throw triboelectric effect around too which is a real issue with low level signals and high impedance like say medical, but yes can be audible in microphone cables if they are physically moved and are high impedance. I did an experiment with cheap interconnects placed inches in front of a speaker and powered with a lithium battery and a 2K source impedance to represent a real signal and then put that into a preamp capacitively coupled. Didn't matter how loud the speaker was, even with $1 interconnects I could not detect a signal at the output of the preamp.

 

[redstang]

... My main issue with Danny's videos so far is that they have not shown me how the pricier cable is better than the cheaper cable. He has shown basic scientific effects and extrapolated their effects into justifying cables. I'm open to his videos as I do want to see the science from all angles, and I'm hoping he can show more...

Actually, the main problem with Danny's videos is that he does not show any relevant scientific effects. For example, he shows that speaker wire can pick up RF, but then ignores everyone in the comments providing point after point as to why that doesn't matter and isn't audible in any normal speaker wire use situation. His entire argument always boils down to there being distortion in a wire, and while the audible effects of that distortion can't be measured, if you listen you can tell the difference. And if you don't have a super high resolution set up, and don't actually listen, you're not doing any 'science' - as though subjective listening tests are science. He has a very frustrating amount of cognitive dissonance when it comes to that stuff, because he obviously understands measurements as he measures his speakers. But instead of engaging in any actual debate with anyone knowledgeable about the science, he calls them flat-earthers, in a bizarre reversal of the use in that term, because he is 100% the flat earther in these debates, denying all the electrical engineering and physics that say that none of this so called distortion is audible.

 

[audio2design]

What are the odds GR actually goes through with the blind test on video:

 

[bboris77]

What are the odds GR actually goes through with the blind test on video:

It's been 4 months since he accepted the challenge. I have given up hoping it would happen to be honest. It is a shame because I am genuinely interested in this type of blind testing, especially by people who have the means to make it happen.