Mr. Speakers ETHER Flow Headphone(?) Upgrade(?)

Thank you for the link, it's a cool animation. What I take from this is that things are a bit complicated for a headphone because we are in the acoustic near field of the driver so it's difficult to imagine what happens in actual headphone.

Earlier, I had a look at how perforated panels behave because I assume this is the same thing going on here. Here's a copy / paste from head-fi post (hope those who read both threads won't be too bothered...):

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Quote:
Originally Posted by soren_brix

perforated grills - assuming the holes are more than one diameter apart will have approx the 1/n acoustic impedance of one hole and will be depend on the wave length.
As for Helmholz resonators the 'size' of the acoustic elements comprising the resonator will influence the actual wavelength the resonator will impact - so basically it is the other way around.
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Where did you get these references from?

You got me worried because I am supposed to understand acoustics something for my work lol.

Anyhow, just to illustrate how perforated grills work, I found this nice web calculator: http://www.acousticmodelling.com

Check for yourself but increasing the thickness of the panel (e.g. the length of the neck) decreases the fundamental frequency where absorption peaks out.

Here an example going from 6mm thick panel (blue color) to 1mm panel (green color):



It's not a simple as a bunch of helmholtz resonators sitting next to each other and working independently, see for instance influence of hole space below and maybe this is what you are trying to explain? Here an example going from 10mm spacing (e.g. 20% open grill, blue color) to 20mm spacing (e.g. 5% open grill, green color):



In any case, I don't know for what angle of incidence the above was computed and it's not applicable for the funnel type Dan is working on so I may try a more evolved calculation using 3D geometry.

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Quote:
Originally Posted by fiascogarcia

Me no understand. Me only want it to sound good.
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Quote:

Originally Posted by griff2

Me to, but there's a lot of psudo scientific bs associated with hi-fi. Just want to make sure that those pretty YouTube vids have any base in reality.
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Dan agreed to contact me again when dust settles down for him and I hope I can run a couple of acoustic simulations to highlight the benefits of this funnel.

One importance piece of information I got from reading the SF meet impressions is @Currawong comment about the Ether Flow using a thicker absorber pads in front of the driver.

This definitely plays a role in the performance of the system, see example in terms of absorption with the same web calculator, using 0.5mm thick absorber pad (blue color) vs. 3mm pad (green color):



BTW, my assumption above is that the acoustic absorption effect you get from placing a perforated grill in front of a wall with a gap can also be used to change the acoustics of a planar or estat diaphragm which couples to your ear through similar system (the air gap is represented by the earcup and the funnel here or otherwise perforated stator facing your ear is the perforated grill)....

cheers,

arnaud

 

I think part of the issue is that we are trying to apply macroscopic physics at the wrong size scale. Sound waves can bend around objects, and after a certain distance the disturbed wavefront has somewhat homogenized. Same thing happens with a grating, but there's so much grit right at the grating itself. Getting a generalized idea of turbulent flow is easy, but understanding that turbulence right at the surface is tricky balls.

The same goes for the uneven acoustic impedance seen by the driver across it's surface. The airspace region between the diaphragm and magnets must be a mess.

 

I agree that there is little point in trying to understand the acoustic performance of this funnel by looking at what happens in the near field because of all these evanescent waves in the acoustics nearfield. It's more for pretty picture I suppose ;-).

One thing that tickles me though is to think that acoustics of these perforated panels relate to air flow through perforations. This is beyond silly as the only case I know this applies is when there is significant mean flow in addition to acoustics (like mach number > .3 or something, think jet engine nacels) or very tiny perforations where viscosity effects matter.

Worse thing is, if you look at the head-fi thread is some guy is adding to the confusion by basically saying airflow matter and he knows because he's an engineer... What can I say, I meet good engineers and less talented ones at times, just like some hobbyists sometimes know more than doctors...

Cheers,
Arnaud

 

not first time...i was around at headfi on the modding community of ortho's and the t50rp way before that special person came around. i remember clear as a bell when the first comment i ever read of his was somewhat like ''hey guise! i'll be making a modified t50rp to sell to everyone! i got me some measurement gizmos!''....ok, not exactly like that but, it came out like that in my head when i read it. he got wind of the thunderpants and other couple modders making some custom stuff for individuals so he decided to try to hop on the bandwagon to monopolize on the people... i actually got yelled at for jesus face palming him when he made that announcement....

 

I'm all for capitalism, entrepreneurs (I am one), etc. I just don't want to see th the community taken advantage of.

 

Whoops!

 

At the end of the day, we all vote with our dollars. I voted a resounding NO to Mr. Speakers in the past and will continue to do so.

 

The problem with bigger more powerful magnets is that is typically translates to more weight. After being in and around the headphone hobby for 10 years now, comfort is number one for me over sound quality. If you can't build a sub 400 gram headphone, then go back to the drawing board. I need all day comfort.

The Elear would be high on my list if it weren't for the weight.

 

I agree.. Although I've been told that the solid yokes help distribute the Elear's weight well. Still I know the Ethers are supremely comfortable so I'm still debating between Ether Flow C and Elear...

 

^^haha. Not a bad headphone really, ma900. But the ridiculously low weight and comfort on the 650 do add the total enjoyment for me.

 

Also considering the diaphragm side of the magnet assembly, perhaps the funnels help to create a more even pressure distribution/acoustic impedance seen by the diaphragm. After all, the diaphragm in theory feels an even force across it's surface from the traces and tensioning, but the air resistance pushing back down on it is kinda like polka dots. I don't imagine that's the smoothest feeling (or maybe I'm wrong at this scale and it all events out).

Of course, now again I'm assuming conventional large scale air flow physics. I'm not entirely certain how much it changes on the small scale. I could probably hack out the boundary layer equations making some assumptions (that it is fully turbulent vs laminar flow, and air flow speed = mach 1), but my fluid dynamics aren't *quite* good enough to handle a tapered wall. In this instance we may also have to consider that the magnet assembly is acting like a compression/expansion cycle, which has all sorts of lovely effects on airspeed etc going through it.

 

It certainly says something to me that people consider the Ether C (and Flow) as competitors to open headphones.

 

I would suggest that you audition the PMx2... I have a penchant for them.

 

There is so much talk of this diffuser/waveguide, but not much of diaphragm. Its thicknesses, material, active area.