Diffraction and its effects . .

I found Jim's diffraction guides to be very worthwhile on my ES14's they even had an audible effect down into the mids IME.

Quote:

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Originally Posted by YNWaN

The effect becomes less relevant as frequency descends and the wavelength lengthens.

I would say that what the ribbon tweeter guys have told you isn't really true as such. Mounting the ribbon in a recess doesn't directly address the issue, which is endemic to the propagation of high frequencies. However, the more directional the output of a tweeter is, the less likely the problem is to occur.

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Ok, so it applies to HF only.
Thanks for that.
I can envisage the phenomenon for domes etc where the radiation from the drive is pseudo-radial, and however fractional the power, may interefere with angled surfaces which are tangential near the mounting surface, but beyond that I'm getting a bit confused as to my understanding of how a radiator behaves in a waveguide, the resonant frequency of the casing, and the frequencies involved.
Can you explain please as kinda lost now.

Nice discussion, fellas. I do understand the ripple effect, of course. The purpose of the wool pads is to absorb and dissipate short and spreading or rippling high frequency waveforms produced by surface or flush mounted tweeters for those who are following the discussion and may not be quite so scientificly endowed, so they are not re-directed into the soundfield arbitrarily (see link) and distorting what the microphone(s) captured on location. I've done my homework. They work real good. Again, great discussion.

http://www.silcom.com/~aludwig/images/diffdem.gif

You mean these, Sq (at the bottom)?
http://surrounds
Thanks for chiming in. Here's a review from Filterlab posted right here some months ago:

"Like most audiophile chaps, I'm definitely up for a tweak which is preferably all of the following things:

1. Effective
2. Easy to install (i.e. doesn't require a degree in electronic engineering!)
3. Cheap.

So as if by chance the perfect tweak offer dropped into my lap seemingly out of nowhere! After extensive listening and loving of my Revel M22s and having tried them on different surfaces and with different cables etc etc I was very VERY pleased with their performance, surely nothing could make them even better?

Well yes actually, and for a darn sight less than they cost to buy. In fact an amazing tweak was had for just 1.4% of the price of the speakers. YES! For £28 including taxes and shipping, my esteemed acquaintance Jim from diffractionbegone created a pair of baffle covers to perfectly fit my speakers.

So the science is not really up my street, but what I can hear are the effects of a scientific principal working in my favour, and boy can I hear a difference with these things! Have a look and see how they fit, and I'll tell you how they effect (read as 'improve') the sound.


(Sorry, couldn't bring the pictures forward but an example can be seen in my avatar)


Now you may balk a little at the looks, but in the flesh they look superb and if I'm honest the looks have really grown on me. However, it's not about the looks I hear you say. So the sound...

Well my friends, the difference these things have made is nothing short of staggering. I was expecting it to effect the treble, but in actual fact it's quite the opposite.

The first thing that really struck me was the midrange clarity - think 'crack of the snare', 'clap of the hand' and 'strum of the guitar' and you're on exactly the right lines. The focus in this audible region has to heard to be believed, but that's not all - oh no! The other amazing element is in the bass lines, particularly bass guitar, which takes on a start/stop nature that is as tight as the deft handwork as any talented guitarist. Again I'm going to use the superlative 'focus', clarity in this region is so improved, amazingly in fact.

So is that it? Nope, there's two other areas which are even more impressive, namely imaging and vocals. Imaging on my Revels was always a little bit of a sticking point after owning some Martin Logan electrostats, but these baffle covers have augmented the imaging to near-electrostat levels, and that's saying something. I guess this is why vocals sound sooo good, they just stand so clear from the mix with such audibility and yet never become overblown.

If you have thirty quid that you fancy putting towards a positive tweak in your system, you'll NEVER go wrong with these."

Le petite bump for the preservation of sound waveforms and the information they carry, all your system is working in earnest to produce.

Check out my ES14's in my previous house, now there was a well damped room.

I found the use of wool refraction rings to remove slight sibilance and reduce off axis dispersion from the corners that can distort the sound stage.
I used some wool felt circular ones from Madisound.
I wrote the review. http://www.madisoundspeakerstore.com...t-page-reviews
There pretty thick wool felt and fit perfectly over the metal body of my tweeters and don't look out of place,you don't even know there there unless you look closely.
They are cut from the wool felt they sell in bulk and have an adhesive back, I talked to the Tech that cuts them out with a die tool.
It's well worth the effort.