Magnets in Audio: How Do They Work?

[RBFC]

If we are such deeply dedicated audiophiles, who really would like to know what to spend our money upon, I think it's incumbent on those who have the capability to set up some tests to prove/disprove some of this stuff themselves. While the tests may not be perfect in "scientific rigor", they are still a step toward understanding....certainly far better than us just sitting here on our forum and spouting all sorts of unverifiable things. Mike Lavigne, certainly a devout audiophile, has participated in many listening tests because he has a great drive to know more about why and how things act as they do. I hope that more of us follow this example and help push the art of music to blend successfully with the science of audio reproduction and acoustics. There really aren't "two camps", there's just the hassle of trying to bridge the gap with terminology and desire for progress.

Understand that I'm not poking at anyone with these statements. I'd just like to see a more proactive approach here, which could catapult our forum ahead of the other "repetitive discussion" forums. We certainly have some blue-chip minds here!

Lee

 

[garylkoh]

The OP has no doubt that they work and are an improvement in his system. He has the devotion and dedication to understand more and asked for insight. Dismissing the audibility of the effect because there is no supporting data does not contribute to progress.

I'd just like to see a more proactive approach here, which could catapult our forum ahead of the other "repetitive discussion" forums. We certainly have some blue-chip minds here!

I just put a large neodymium magnet next to the power cord on my phono stage (most sensitive piece of equipment to power cord changes), and there was no effect I could hear. Then a pile of ferrite magnets, and still no difference.

But this does not mean that magnets have no effect, it only means that what I have done with magnets have no effect in my system detectable to my ear/brain.

 

[RBFC]

Thanks, Gary! This is exactly what I was saying. Try this stuff out if possible. Personally, I'm in no position to say that something does or doesn't work. Independent testing, with statistically significant consensus, should imply that there is an effect worth detailed scientific study. There are far too many interactions between EMI, noise, etc. for us to make singular statements regarding small effects such as described. Yet, the possibility of the existence of effects should drive us to find out more.

Lee

 

[RBFC]

As a corollary to this discussion, what is the general opinion on the use of ferrite chokes on cabling to reduce/eliminate RFI?

Lee

 

[Gedlee]

As a corollary to this discussion, what is the general opinion on the use of ferrite chokes on cabling to reduce/eliminate RFI?

Lee

If you have analog components with long leads, or known RFI problems, then these would be a good idea since the VHF stuff could cause problems. But if you are like me and only run external signals that are either digital or high level signals (speaker leads) then the chance of any RFI problems is quite minimal. If they did exist then it would be quite noticable as an unstable digital signal.

 

[microstrip]

As a corollary to this discussion, what is the general opinion on the use of ferrite chokes on cabling to reduce/eliminate RFI?

Lee

As ferrite chokes are used to filter RFI, this means they are reducing the bandwidth and probably can increase jitter in digital systems.
When used in analog systems using unbalanced systems, as cables are non ideal and the ground wires also have some inductance, the they can both solve or increase RFI problems.
There is some consensus that they generally degrade audio performance in high-end systems.

 

[DonH50]

Ferrites are also used to improve jitter in some wideband data links... There are always design trades.

I keep reminding myself to stay out of this one... - Don

 

[hendad]

If we are such deeply dedicated audiophiles, who really would like to know what to spend our money upon, I think it's incumbent on those who have the capability to set up some tests to prove/disprove some of this stuff themselves. While the tests may not be perfect in "scientific rigor", they are still a step toward understanding....certainly far better than us just sitting here on our forum and spouting all sorts of unverifiable things. Mike Lavigne, certainly a devout audiophile, has participated in many listening tests because he has a great drive to know more about why and how things act as they do. I hope that more of us follow this example and help push the art of music to blend successfully with the science of audio reproduction and acoustics. There really aren't "two camps", there's just the hassle of trying to bridge the gap with terminology and desire for progress.

Understand that I'm not poking at anyone with these statements. I'd just like to see a more proactive approach here, which could catapult our forum ahead of the other "repetitive discussion" forums. We certainly have some blue-chip minds here!

Lee

Hi, all. I am interested in the potential negative impact of magnets on audio and so was pleased to come across this thread. I am wondering if any of the blue-chips have any insight to offer regarding my particular application. I am considering using neodymium magnets to affix removable back panels to the back of an AV cabinet, maybe 4 or 6 (2 to 3 per side edge), about 3/8" diameter, 3/8" tall - a bit like the end of a pencil. The tops would protrude a tiny bit off the face of the panel and attach to metal on the cabinet. They would possibly come within a few inches of wires/cables and be behind amps, pre-amps, power conditions, receivers, and the like. I know a speaker company uses the same magnets to attach grills to the fronts of speakers. Thanks very much in advance for any insight.

 

[amirm]

No direct insight but a suggestion. Take a magnet and instead of it being a few inches away, put it right next to the cable. Then listen to your music. If you can't detect anything then surely moving it away reduce the effect, not increase it.

 

[garylkoh]

I know a speaker company uses the same magnets to attach grills to the fronts of speakers. Thanks very much in advance for any insight.

Don't know if you are referring to us, but we use neo magnets to hold grills to the front of my speakers. I had two pairs of cabinets built - one with and one without the neo magnets. The two pairs sounded absolutely identical. We even found that magnets and LPs made no difference here:
http://www.whatsbestforum.com/showthread.php?2701-Reviewing-the-Furutec-Demag

I think you're safe with the magnets on the AV cabinet.... but try what Amir suggested anyway. Do a couple of different configurations - one magnet, two magnets with opposite poles (attract) on both sides of a wire, the two magnets with the same poles (repel) on both sides of a wire. The two interconnects that may have the greatest effect (smallest signal) will be the tonearm cable followed by the preamp cable.

 

[slowGEEZR]

http://en.wikipedia.org/wiki/Magnetoresistance
Magnetoresistance is the property of a material to change the value of its electrical resistance when an external magnetic field is applied to it. Less resistance in a cable could be a good thing, yes?

 

[DonH50]

1. The effect is far too small to matter for practical audio circuits. (I suppose that will start a debate...)
2. The effect is directional, so technically it would help in one direction of current flow and hurt in the other. Audio signals alternate in polarity...
3. After years of research and more putting it into practice, GMR is used in some disk drives and other (relatively esoteric) areas. So, it is useful in practice, for some applications, but see (1).

 

[NorthStar]

Do they use magnets in nuclear reactors?

 

[hendad]

Thank you Amir. I will experiment.

 

[hendad]

Hi, Gay. No, was not referring to your company, but the fact that you also use the neo magnets tells me it's an acceptable practice. Thanks for your input. Thanks to the others as well.