Review: Diffraction be gone Anti-diffraction tweeter surround Tweak

Category: Accessories

I order a pair of the anti-diffraction tweeter surrounds for my Silverline audio SR17.5 monitors. Not that I was unhappy with the performance of my speakers but at just $50 it was a cheap enough tweek to give it a try.

The surrounds were made to my exact measurements and shipped quickly. They come with stick on velcro pads to hold them in place and this does work well.

I put them on and sat back with some Diana Krall. The image was very focused and clean and clear. It gave that immediate wow factor. This trait was even more apparent with movie soundtracks, making dialog more intelligible.

Over the course of a few weeks it became apparent that something just wasn't right. Lots of on and off with the pads followed. What I discovered was that the highs were being rolled off and the air in recordings was being removed by these pads.

After a few days of trying them on and off I cannot bring myself to put them back on. The air and life is lost to the pads. These pads are quite thick and I wonder if a thin pad would have the same effect.

Like a lot of things that immediately wow it is just a matter of time before their true flaws are revealed.
Some time ago I tried sticking very thin felt around my tweeters and I found the same effect you described.
My understanding, subsequently, is that the Silverline designer has the forethought to lower the output of his product/tweeter precisely in the lower bandpass of the tweeter where diffraction effects will cause a rise and uneveness in the frequency domain. That's hip, but does nothing to remove the time and phase disorder to the signal when diffracted waveforms arrive late and combine. So, it is only in one respect that diffraction effects are being made more benign. In the other, time and phase error caused by the late arrival of diffracted waveforms (of the same information), this does nothing.

What is missing from Gear's eval and perhaps escaped his attention is the 3D roundness and transparency of space in a recording when diffraction effects are removed. Tho he did cite improved focus. Damn straight there is. Look at Gallo or Gradient loudspeakers, or Vandersteen. No baffle. Image like bastards. No diffraction is the reason. Gear misinterprets a loss of air. It's the very early reflection off his baffles and edges combining and reinforcing is what is missing. That, is a distortion to a recording. Further, it comes at a price to absolute dimensionality. Air is there, more naturally. Just as it was 'hesrd' by the microphone(s). So long as some guy in a booth hasn't f----- it up.
Paint the tweeter faceplate with a finish from Cascade Audio
called V-Bloc. This product goes on a wet dark purple and drys hard as rock black. This will tame much resonance build up on the actual plastic or metal chassis that houses the driver. For even better results remove the drivers and paint the back plates and metal chassis of the drivers...and to make a even more dramatic improvement paint the entire interior enclosure with this product. Result is 3d. No glasses required.Tom
Whoops . . mispelled 'heard' in my previous post. Didn't want you to think I'd been drinkin. Too much, that is. Here is a reply from an enthusiast of which I have lots-

"Jim, after a week of use on the VR1s and VR4JRs I'm convinced these pads are not going back. I really like what they do each of my systems. Overall the impact of the pads seems to be to create sharper transients, more detailed imaging and improved image focus and significantly truer-sounding instrument timber. The general impression is for instruments and vocals to have more of a live performance sound with the sound becoming freed of the speaker boxes. And finally, while nothing actually sounded harsh before the pads, with the pads there seems to be a more effortless, natural-sounding presentation of the music - as though there was some harshness I wasn't aware of that is now gone. It feels like I'm finally hearing what my system is capable of, what I've expected with every other upgrade and never found , and finally hear. Thanks for a giving me the sound I've been looking for.

Next week, RMAF is in town and I was looking forward to attending in order to hear a few speakers I've been interested in. But with these improvements, and the dreadful state of the economy, I can't imagine I'm going to hear anything that can beat what I now have with your pads, without paying what my entire system costs just for speakers. I think you just helped me get off of the upgrade bandwagon. Joe G."

The chap lives in Denver hence the reference to RMAF. He didn't mention air, but this cat did-

"Like many, I've seen the felt 'diffraction units' used my manufacturers here and there. I've heard speakers with them, but I've never been able to A/B them in order to discern any improvement or deficit for myself. Aesthetically; I like my baffles to be bare as I am fond of wood grain. However the audiophile in me always wondered if there would be any real positive benefit from them...

When Jim started posting pictures of the Touchstone Tweeter Surrounds here in AC a couple years ago, I thought "hey, there we go, I should give those a try" It did take me a couple years to get around to it, but I finally contacted Jim and decided to go for a set for my Totem Hawks. I know that Vince takes extra special care when constructing his cabinets, but I figured: why not try?

Now I didn't expect any revelations from these. Frankly: I mostly hoped that they wouldn't go on my long list of tweaks that kill dynamics and hf response...

Well, let me start off by saying that the difference is so profound; you can hear it immediately. By that same token, it's very easy to test: just remove it.

It seems that some of what I had perceived prior to installation as air, was in actuality hf glare coming from the baffles. With the tweeter surrounds in place, the glare was gone and focus had taken its place. Detail quality has improved greatly, especially drums, voices and piano. Imaging and soundstage have a greater illusion of "in the room" presence. There's plenty of air, but it now seems more natural. In short: these truly help bring more natural musicality from the speakers.

Removing them brought my system back to what I remembered. It's still an outstanding sound, but not as refined and I missed them. So surrounding the tweeters they will stay.

My system is now more involving than ever before, which has to be my ultimate goal for playback. These are definite winners and must-haves in my opinion."