Members halfnote Posted July 30, 2008 Members Share Posted July 30, 2008 I've been a musician for decades but much of my tech knowledge is piecemeal...bear with me when I sometimes intrude. Recently I read an ad for a monitor speaker that touted it's new design with rounded corners on the cabs as "reducing edge diffraction & improving stereo imaging". Really?How's that work? Darryl Weaver Link to comment Share on other sites More sharing options...
Phil O'Keefe Posted July 31, 2008 Share Posted July 31, 2008 It has to do with the way sound radiates out of the drivers and reflects and diffracts off the edges and surfaces of the speaker enclosure. If sound bounces off a nearby surface, and then arrives at your ears along with the direct sound from the speakers, that can "smear" the stereo image. That's why most acousticians and acoustic materials companies suggest treating the "first reflection points" in your control room. Sound arriving outside of what is known as the Haas window (about 20ms or so later than the direct sound) is normally perceived as ambience or reflections, as opposed to being indistinguishable from the direct sound, so longer distance reflections are not always considered "bad" - but reflections off of nearby walls, your mixing desk and even parts of the speaker cabinets themselves can fall within the Hass window and cause issues. Link to comment Share on other sites More sharing options...
Phil O'Keefe Posted July 31, 2008 Share Posted July 31, 2008 BTW, sound travels at 1,130 feet per second, so anything that takes less than about 20' or so to do the "round trip" and reflect back to you may be an area that causes problems and should be considered being treated. A quick way to check for areas to treat involves using a flat mirror held (by an assistant) flat against any wall / ceiling surfaces nearby - if you can see a monitor reflected in the mirror when seated at the mixing position, and if that surface is less than 10' away from you, then it should probably be treated to reduce those reflections. Link to comment Share on other sites More sharing options...
Members TBush Posted July 31, 2008 Members Share Posted July 31, 2008 BTW, sound travels at 1,130 feet per second, so anything that takes less than about 20' or so to do the "round trip" and reflect back to you may be an area that causes problems and should be considered being treated.A quick way to check for areas to treat involves using a flat mirror held (by an assistant) flat against any wall / ceiling surfaces nearby - if you can see a monitor reflected in the mirror when seated at the mixing position, and if that surface is less than 10' away from you, then it should probably be treated to reduce those reflections. What? You've got an assistant? Link to comment Share on other sites More sharing options...
Phil O'Keefe Posted July 31, 2008 Share Posted July 31, 2008 No, I've yet to find the "right" assistant. But holding a mirror flat against a wall is something you can get just about anyone to "assist" you with. Link to comment Share on other sites More sharing options...
Members gearmike Posted July 31, 2008 Members Share Posted July 31, 2008 What they're talking about with "rounded corners and diffraction stuff" is that if well... Let's see if I can explain this in a non-physics kinda way... If you have a driver on a baffle...the sound radiates straight out from the driver, but some amount also travels along the face of the baffle, ok? When that sound reaches the sharp corner of the baffle, it radiates from that corner, as if there's another phantom driver there at the corner. If you round over that corner, the sound continues along the surface and is not re-radiated... It's the elimination of these "phantom-drivers" that "tightens up" the stereo image-ing. Keep in mind that different frequencies will travel farther along the corner and different frequencies will diffract at differring heights along th corner and... Well without breking out the charts and graphs, lets just say that round corners are not just pretty, they make a huge difference... -Mike Link to comment Share on other sites More sharing options...
Members halfnote Posted August 1, 2008 Author Members Share Posted August 1, 2008 Thanks...I'd just never heard anything so "tight" as this point about rounding the cab's corners. Link to comment Share on other sites More sharing options...
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