[Duke]

In the latest issue of The Abso!ute Sound, Robert E. Greene singles out Jim Goulding's "Diffractionbegone" thick felt anti-diffraction pads for a Golden Ear award.  Quoting REG:  "If your speakers suffer from tweeter diffraction-effects, these elegant and inexpensive felt devices will make an improvement all out of proportion to their low price."

Okay let me give you my take on diffraction, drawing from conversations with Dr. Earl Geddes.  Diffraction can degrade not only imaging but also clarity, because while the ear is very good as masking (ignoring) a coloration that arrives at the same time as the original signal, it is very poor at masking when the coloration arrives at a different time.  A look at diffraction's effects on a frequency response curve does not begin to reveal how the ear responds to it.  The most important region for diffraction control is around 4 kHz, as this is where the ear is most sensitive.  It is also the region where a tweeter's radiation pattern is very wide, so there's more energy to diffract off the cabinet edges in that region than elsewhere in the spectrum - a rather unfortunate situation (which now can be effectively addressed at a very reasonable price).   Also, diffraction is more audible at high sound pressure levels than at low levels.  The edginess that characterizes most prosound systems at high volume levels is largely the result of diffraction and diffraction-like artifacts (and not driver non-linearity).

Note that Jim custom makes his devices for your specific speakers.  So for less than the price of a tank of gas, you can make a significant improvement in your sound system.  Significant enough to be honored with a Golden Ear - and this is THE LEAST EXPENSIVE product to be so honored.

Congratulations, Jim! 

Duke

[pbrstreetgang]

Do they come on AK speakers?

[TheChairGuy]

Yeah I saw/read this today in my free Absolute Sound at the Public Library - congrats Jim (and further congrats to you, Duke) 

I thought it amazing, nee surprising, that a $55 item was given a Golden Ear...good going, all.

John

[Duke]

pbrstreetgang, I'm taking a different approach - using a waveguide to control the tweeter's radiation pattern (similar to what SP Tech and Emerald Physics do).

That being said, if the day comes when I offer a "conventional" speaker, Jim's product would be on it. 

Note that Robert E. Greene is a strong proponent of uniform radiation patterns, and he recognized in Diffractionbegone a cost-effective way to make a very worthwhile  improvement in that area. 

Duke

[jimdgoulding]

Duke-  That is generous beyond any expectation I might have had.  And thank you for the technical info and the source.  That was a nice way you replied to the member who lacked appreciation of what is available to him.  I've begun to tell new customers to focus on the space first before they focus on what's in it.  Sort of a back door approach to perception but one that can be revealing.  The delivery of information is just as important as everything in front of it.  I know you know that.  It's encouraging to me and should be to everyone to see dynamic speaker designers such as yourself take steps to see that information arrives intact w/o diffraction or early reflection contaminating it.  Hope I get to hear your speakers this year.  The last few customers I've gotten came as a result of Robert Greene's acknowledgement.  Hope you do, too.  Thank you, Duke.

[pbrstreetgang]

What do you mean lacked appreciation?

[jimdgoulding]

Street-  Of the moment.  Or, of the science, maybe.  No offense if any was taken.  Very likely I misunderstood you altogether. 

Duke-  Wow!  Saw your posts on AA and A'gon.  I think you're my new best friend!  Again, thank you (a heap).

Thanks, Chair.  Sure you don't want to meet my old girlfriend in Fairfax?  She'll make you think you're carefree and twenty, again.

[TheChairGuy]

Thanks, Chair.  Sure you don't want to meet my old girlfriend in Fairfax?  She'll make you think you're carefree and twenty, again.

Well - first, I'd have to ask my wife 

Second, are you sure you've seen a recent pic of her?...I think you said it's been decades since you lived here/there....the food and grog is plentiful in Fairfax, CA and she coulda' indulged over the years (sobbing - over losing you  )

John

[jimdgoulding]

Yeah, John.  You got a couple of points there.  She was a beautiful creature in the day.  Has it been decades since I lived there?  I suppose it has.  Geez.  What a bummer.

[jimdgoulding]

Duke-  Good morning.  I would like to thank you, again.  I'm especially grateful for the fact that you answered questions when you could have simply gone on about your business.  Audiogon will not let me reply and they DO piss me off, but Audio Asylum has to this point.  I think they believe it is of interest to inmates and that's why.  What can I do for you, Duke?

Danny Richie put me in touch with Sean Parque, an authorized modifier for AV123 speakers and Sean has included my product as a component to his latest crossover upgrade kit for their Reference One (pictured in my avatar).  A dealer/speaker designer in Australia, one much like yourself only with not so much innovation, Andrew at Aslan Acoustics, is making it available as an accessory to his line of speakers. 

I am sure grateful to you, Duke, and many, many members at Audio Circle for your open mindedness and support.  Contact me at anytime for any reason.  You ! 

All the best.  Jim

[Wind Chaser]

***Diffraction can degrade not only imaging but also clarity***

***The most important region for diffraction control is around 4 kHz, as this is where the ear is most sensitive.* **
 
***diffraction is more audible at high sound pressure levels than at low levels.***

Simple and succinct... Thank you very much!