Some would call this 'voodoo'. I admit that, with whatever little science I learned in school, I myself do not know of or read of a fully convincing explanation of this effect. But that is just me.

The 'theory' of system demagnetizing goes like this - the ferrous (magnetic) materials or impurities in our system can get magnetized after a long use. This magnetism could negatively affect signal flow. Running a 'special' signal through the system, from the frontend all the way to the loudspeaker, will demagnetize the system, i.e., randomize the polarity orientation of the magnetic materials. (Well, you can think of a few whys and hows on these statements, can't you?) :-)

Leaving the basis of its working aside, whether 'demagnetizing' works on our hifi or not polarizes audiophiles' opinion too. However, based on my many years of doing 'demagnetizing', I say it has an effect in my system.
The 'special' signal comes in a number of varieties apparently, I myself have 3 different versions on CDs. However there is also a hardware based version - the Gryphon Exorcist, it is the first product that I am aware of (in the early 90's I think) that offers system demagnetizing.

The content of my 3 different versions are different. On the Stereophile Test CD 3, it is simply a 1khz tone that fades to silence in 23sec; on the XLO & Reference Recordings Test & Burn-in CD, it is a frequency sweep, starting from the bass, progressing through the mid to the treble in a minute. The Densen DeMagic CD has only one track, which is 3 minutes long. The track contains bass, mid and treble components (but is not pink or white noise) which slowly fades, it also has a 'chirping' sound interspersed into the track.

I found the least effect with the XLO/Reference Recordings disc (but I do enjoy the music that comes with it, excellent recording quality from Reference Recordings).

I use the Stereophile disc the most, because it is the most convenient (short duration) and the least noisy. However, its effect can go 'overboard'. Sometimes after running the demagnetizing track, the system sounds a little too dark and slightly shut-in (the highs got curtailed quite a bit), but it will recover in 2-3 days.

It was the Stereophile disc that made me a convert. In my early hifi days, I used a pair of Nordost Flatline Gold speaker cables in my entry level set up. Over time, I found that the system sounded too sharp and too bright, very analytical, very uncomfortable to listen to. I blamed it on the Nordost, and switched to a pair of warmer sounding speaker cables. My system was more listenable but I lost quite a bit of details. When I found the Stereophile test CD, I gave the demagnetizing track a spin, and lo and behold, everything calmed down. Switching back to Nordost, I found that it was indeed the superior one - clearer, more transparent, faster. Since then, using the Stereophile disc became a routine for me.

I use the Densen disc occasionally. It is the longest and noisiest wait. Its effect is always positive though, but the magnitude of improvement varies with each run. I suppose this is dependent on the condition of the system at that time. If you can live with the noise and the time, it is the best among the three.

I think it is good to leave the room (or at least cover your ears) when running these tracks, so that they do not affect your 'hearing balance', if you want to do a comparison of before and after. :-)

So how do I know when I need to demagnetize my system? Usually, one two months or so after a previous run, I'd start to detect some roughness in the highs, the system could sound a little 'jittery' or noisier, there could be some glare or brightness. One would normally have the urge to want to tinker with the equipment and cables already at this point. I got to remind myself to hold the horses and run demagnetizing first at moments like this. :-)

What is the effect of demagnetizing in my system? It usually reduces those negative effects. The feeling after is like looking at a scenery after heavy rain - cleaner, clearer, and more vivid. The background is also quieter.

I can't detect any negative physical side effect on my system (it is not like the equipment will break down or drivers will blow), so even if we want to call it 'voodoo', there is no harm in trying it out. If it works for you, then that's great.

P.S., Isotek also has its version, but I have not tried it myself.


Anonymous said...

I found the effect of the Isotek significantly better than the XLO.

I don't have the Densen to compare with but in Hong Kong the Densen disc is several times more expensive than the Isotek.

audioexplorer said...

Ayre/Cardas has a CD that does something similar to the three mentioned. I use it very occasionally, maybe once every two to three months. It can easily be overused and make my system sound dry and uninvolving.

audioexplorer said...

Ayre/Cardas have a similar CD with a demagnetizing track that lasts 5 minutes. I do it approximately once every two to three months. Which allows the midrange to sound more open and the highs to sound more sweet and extended. It is easily over used and can make my system sound dry and uninvolving.

Anonymous said...

Ayre also a version which I prefer to the Densen.

Anonymous said...

For the Ayre CD, I run the long track once a week and the short track once a day. These are best practice recommendations are from Charles Hanson of Ayre.

audioexplorer said...

That is indeed Mr. Hansen's recommendation and in many systems he is correct. I my system it's just too much.