The same improvements have been reported with shielded IC cables, and exotic cables that start out at 900pF/meter, and them of course the myrtle.
900pf/meter that should be easy see a difference with ! I see improvement with those mainly in a RF rich field . There are two main question to me 1. What tests correlate to what we hear. 2. Are different material cost effective. Examples poylprop vs mylar yes, polystrene vs Teflon not so much . Copper verses tin yes . copper vs silver not always. That from a listening stand point nor a measured resistance point. This brings me to speaker wire and how we look at it from a dc resistance point very small but when viewed from ac impedance a wide bit of difference .The same improvements have been reported with shielded IC cables, and exotic cables that start out at 900pF/meter, and them of course the myrtle.
Actually, free air will have a lower permittivity than everything else with the exception of a vacuum. That's why the data suggesting higher capacitance while suspended drove me nuts..it was yelling at me...
The difference of 1 pf per foot, or 10 pf for a ten foot run buried in a 35 pf/ft cable is not really a large difference. Relative humidity and barometric pressure may produce higher changes within the equipment.
Me personally, I wouldn't worry about a few pfs or nH's in an audio system, but that's just me.
jn
I think you hit on the larger variable humidity and barometric pressure in evaluating a system. Differentiating between real and placebo effects may well be buried deep below the air humidity and pressure changes.
What I meant was, those two factors may produce effects larger than the 1 pf per foot of a cable being pulled or relaxed. I didn't mean that they were audible effects which confound listening tests, but ones that may be possible to measure wrt capacitance.
If we're gonna worry about a picofarad or two, then we might as well start building sidewinder components for ford aero. Configuration control out the wazoo...
jn
Sorry I am not worry about pf not in the app. To the best of my knowledge I do not suffer from audio nervosa as so many audiophile appear to. This is more musing about variable that are not taken into account with listening tests and are there measurement that have better then .5 for a correlation factor . So far they are few.
Agree , experience such alot since using aluminum cone drivers , drove me nuts figuring it out ...
Funny, I have put both a barometric air pressure and humidity sensors in my portable radio. It was more of an experiment in using the devices. I did not think that it would be used in evaluating the sound of the audio device.
So, now we need to place the listening room inside a Thermotron chamber = good one.
A.Wayne,
Though I am not a big fan of many metal cone applications I fail to see how an aluminum cone would be more prone to changes from humidity or barometric pressure changes compared to a standard paper cone driver. As far as humidity changes how could that possibly affect a material the does not change due to that factor? Barometrically I wonder what your ideas are there?
Though I am not a big fan of many metal cone applications I fail to see how an aluminum cone would be more prone to changes from humidity or barometric pressure changes compared to a standard paper cone driver. As far as humidity changes how could that possibly affect a material the does not change due to that factor? Barometrically I wonder what your ideas are there?
KH posed the question because you agreed on the points of humidity and barometric pressure.
So, now you are mentioning temp instead.
Any idea on why temp would figure into it?
jn
The temp may have the larges effect on the listener rather than the transducer.
Another most excellent java calculator from sengpielaudio, I was surprised at how much the attenuation of air varies with humidity, seem to surpass prop velocity effects.
Calculation speed of sound in humid air and the air pressure humidity moist air density of water atmospheric pressure - sengpielaudio Sengpiel Berlin
I thought i had answered the question by adding temp to the equation, it was not mention "instead". I was not able to measure the humidity to see how much of a difference, but i did measure temp and approximated relative humidity based on weather report. At a measured vc and cone temp of 60degF (30% approx RH) the bass was noticeable different VS 80degF(80% RH).
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You need to measure RH inside the listening space. Homes tend not to be fully conditioned, I have winter lows of 15% RH and summer highs of 60% or more. That chart has a dramatic breakpoint at the low end and highs could easily have a .2dB/meter frequency dependent rolloff difference summer/winter. The air temperature only varies +-5 degrees or so since it is the control variable.
In the dirtiest details the latent heat/sensible heat/air/moisture/altitude system is VERY complicated.
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A.Wayne,
I can understand the humidity changing the way sound is absorbed into the air. that would be for any type of speaker though, at the same time a paper cone would change its mass with variations in humidity. The temperature changes could be accounted for with changes in the stiffness of the suspension with temp changes. Now if you said the dimensions of an aluminum cone would change with temp that would also be true but the dimensional changes would be miniscule over the length of the cone but I would have to look at the stiffness changes with temp as that would be a more likely a cause of any real measurable differences Even the spider could be changed by humidity as it is more than likely hygroscopic with many open filaments with a lightly impregnated phenolic resin matrix.
Fast42 will tell you this is why you need to exercise your speakers at high levels to get them all warm and happy!
I can understand the humidity changing the way sound is absorbed into the air. that would be for any type of speaker though, at the same time a paper cone would change its mass with variations in humidity. The temperature changes could be accounted for with changes in the stiffness of the suspension with temp changes. Now if you said the dimensions of an aluminum cone would change with temp that would also be true but the dimensional changes would be miniscule over the length of the cone but I would have to look at the stiffness changes with temp as that would be a more likely a cause of any real measurable differences Even the spider could be changed by humidity as it is more than likely hygroscopic with many open filaments with a lightly impregnated phenolic resin matrix.
Fast42 will tell you this is why you need to exercise your speakers at high levels to get them all warm and happy!
Yep . I'm with you on all that stuff , The amp runs at a cool 135deg, the alloy (ribbon) diaphragms dissipates it's heat pretty good, i haven't seen more than 1-2 deg increase in diaphragm temp over static...
Frank would have an humidity problem , he likes his music best , when it's washing over him ...
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