proximity effect of speaker magnets to amp transformers?

[PeterA]

now the darts are where they always were in the past (never moved them). and where many/most of us would have our amplifiers; centered between the speakers and just behind the front plane of the speakers.. it's where most amps were designed to go. which does not make them impervious to circuit/speaker proximity issues, or acoustical influences.

obviously I started this thread with a different thought than this one, about how moving 'unplugged' amps with 'unusually large' transformers away from right next to a speaker improved my sound. now the thread has morphed into how normally positioned amps somehow might affect acoustic performance. it's not a question i'm asking.

Mike, I think the transformers in my Pass amps are pretty big. And they are close to my speakers. The heat sinks also ring with hand claps in close proximity. Given my space constraints, I have not been tempted to think about moving them slightly further away from the speakers, for either reason: the magnetic proximity or the acoustical influence. I have been thinking of relocating my amps in the basement below my speakers, for aesthetic reasons. Now I am thinking it may improve the sound also.

Even if you are not asking this question, I appreciate that you shared your observation about the sound improving when you moved your two tube amps away from your speakers. And then Jack suggested another possible reason for the improvements in sound. That got me thinking about my situation. That's all. That's the way some threads evolve. You may have moved on from the discussion, but the thread is still pretty interesting to me. We will see if it continues or dies out.

 

[microstrip]

Very interesting data point Mike. I can well imagine how the transformer core laminations could be a drag on the fluctuating magnetic fields of the speakers.

A system like your is so revealing that small effects such as this are readily audibly apparent.

On my to do list is to carry out spectrum analysis of magnetic fields in listening rooms and around equipment

Interesting. What bandwidth and magnitude variations are you considering?

 

[marty]

Folks, it would be rather straight forward to measure the magnetic environment around any piece of gear and look at changes due to gear placement using the magnetometer that is in every iPhone or android phone. Indeed, there are several Apps for that!


https://itunes.apple.com/us/app/physics-toolbox-magnetometer/id1003749103?mt=8
https://www.youtube.com/watch?v=alxJ0nOiPLY
https://itunes.apple.com/us/app/sensor-kinetics-pro/id623633248

 

[GMKF]

Folks, it would be rather straight forward to measure the magnetic environment around any piece of gear and look at changes due to gear placement using the magnetometer that is in every iPhone or android phone. Indeed, there are several Apps for that!


https://itunes.apple.com/us/app/physics-toolbox-magnetometer/id1003749103?mt=8
https://www.youtube.com/watch?v=alxJ0nOiPLY
https://itunes.apple.com/us/app/sensor-kinetics-pro/id623633248

Very Cool ! Downloading right now.
Thanks Marty

 

[EuroDriver]

Interesting. What bandwidth and magnitude variations are you considering?

Sensitivity around 100 micro Tesla and up to 1 KHz

 

[microstrip]

As far as I know these iPhone instruments only measure the steady value of the magnetic field, not the variable magnetic field created by audio signals. The value of the magnetization decreases very fast - the magnetic field drops off with the square of the distance very close to a magnet, and as distance increases, the field decreases with the cube of the distance. At distances over one foot, the magnetic field of a strong magnet can be considered negligible.

 

[microstrip]

Sensitivity around 100 micro Tesla and up to 1 KHz

Although variable along time and place, the magnetic field of the Earth is around 50 micro Tesla. Where do you expect to have such amplitude variation in our rooms?

 

[EuroDriver]

Although variable along time and place, the magnetic field of the Earth is around 50 micro Tesla. Where do you expect to have such amplitude variation in our rooms?

Near speaker drivers, transformers, and power cords.

Have some suspicions about magnetic fields produced by AC ring mains in some countries.

Anyway it will be interesting to measure the strength and frequency spectrum of oscillating magnetic fields ;-)

 

[elcorso]

I have this (from Amazon):



I am impressed with the huge emission of certain components, DC and USB cables. And a lot of electrostatic speakers ...!

Roch