Tweeter Surrounds from Diffractionbegone
Published on June 18, 2007
603 Glen Haven Dr.
Conroe, TX 77385
This is a speaker mod which has been available from several sources before but not in such a heavy-duty form , customized exactly to your particular speakers, and with quite so effective and audible a result. They are designed for standard speaker enclosures with flat panels and a surface-mounted dome tweeter. The wider the front of your speaker enclosure is, the more enhancement you will hear with the tweeter surrounds.
Both light and sound waves tend to cause reflections when they encounter objects. This is called diffraction. A treble frequency of 2000Hz has a seven-inch-long waveform, which is the width of many tower speaker enclosures. Such signals are reflected off the baffle of the speaker and arrive at your ears just behind the original signal which comes directly from the center of the tweeter dome. When you get into high end speakers over the $4000 to $5000 level, you begin to see some designs which place the tweeter in a tiny nacelle or pod on top of the other drivers and away from the cabinet in an effort to reduce or eliminate these early reflections, which mask some of the timing subtleties and details which are present in all good recordings. The idea of tweeter surrounds is to soak up and quiet these diffraction effects caused by speaker enclosures in the area adjacent to the tweeters, and thereby create an enhancement similar to that of moving the tweeter away from the enclosure itself.
The Diffractionbegone tweeter surrounds are professionally designed and custom made felt devices of 3/8-inch thickness which are attached to the front of speaker enclosures around the tweeter using Velcro tabs which are included. They are tooled to the exact size to fit any brand of appropriate speaker enclosures. The maker visits the website for your particular speaker brand and model and gets the proper dimensions to make the surrounds perfectly fit your speakers – so they are custom-designed – which was not the case with other such mods previously available.
I had similar circular surrounds on all the speakers of my previous surround system – Celestion SL600sis. They were of a much thinner and less effective felt, however. They definitely improved the already exceptional imaging of those speakers. So naturally I was interested in the Diffractionbegone products. I mounted them easily with the small square Velcro tabs provided, on all five of my Von Schweikert speakers. Then I removed them to audition two SACDs which I felt would clearly show any improvements in the use of the tweeter surrounds: First was one of the many Tacet discs in which each member of a string quartet is given one of the four main channels, to completely surround the listener. I used the Beethoven Quartets recently reviewed Here. The other disc was When Angels Make Music, a new release from Edition Raumklang featuring copies of early instruments from 1594 found affixed to the dome of the Freiberg Cathedral.
The Beethoven quartets in “Real Surround Sound” had definite spatial localization to each of the four speakers without the tweeter surrounds – that is Tacet’s whole idea in their effort to take the surround sound medium and do something dynamic and unique with it. However, with the tweeter surrounds affixed to the four speakers, there was a stronger focus and greatly enhanced realism. The tone of the various string instruments was less amorphous and had more depth. This applied to the surround channels as well, with the cello and viola which Tacet places on those channels also sounding more distinct and real. I got more of a feeling of actually sitting in the midst of the four musicians. It was as though I had invested in a much more expensive tweeter, as used in those speakers over the $10K mark.
The Angels Music SACD used the center channel in its program of vocal and instrumental music of the period the original instruments were made in Freiberg. One of the first tracks on the second disc had an early wind instrument centered on the center channel. Without the tweeter surrounds it sound like sounds – although of excellent quality – just coming out a speaker. With the surround attached it was more focused and natural and seemed to be more part and parcel of the soundstage – not just confined to the center channel speaker. On Track 11 of the same disc there are several vocalists spread out from the center to the right, with the instruments on the left of the soundstage. The high female voice at the center and the high male voice on the right had good spatiality without the surrounds, but with them the singers’ locations took on a more 3D effect – almost holographic in nature.
Other recordings of general orchestral works also benefitted from the tweeter surrounds, though sometimes to lesser degrees. There was usually a feeling of “seeing” more deeply into the soundstage and music. The better the recording was, the more enhancement the surrounds achieved. So-so mono recordings seemed to be the least improved by the surrounds. I’ve done three mods to my speakers: Bybee filters on the inputs, a 10-lb. lead block on top, and TechnaSonic vibration absorbers on the backs. This in addition to the sand-filled bottom of the four main towers. I found the tweeter surrounds as hearable an enhancement as the TechnaSonics, and in some ways similar in their effects. Both also had the demonstration advantage of being easy to quickly remove and audition without, and then replacing quickly for A/B listening tests. I think anyone with dynamic speakers on flat front panels and dome tweeters would find the Diffractionbegone surrounds a mod that delivers results for reasonable cost.
- John Sunier