coolhandjjl Posted February 8, 2013 Share Posted February 8, 2013 I have been looking at lots of pics of cutaway k horns, diagrams of the pathway out of the k horns bass horn. Is the chamber behind the woofer sealed? That narrow rectangular opening right in front of the woofer, is that some sort of phase plug for the horn? Quote Link to comment Share on other sites More sharing options...
ZAKO Posted February 8, 2013 Share Posted February 8, 2013 THE bass horn has a side door to remove woofer if need be ,,,but yes its sealed,,,The Bass bin has no phase plug.. Quote Link to comment Share on other sites More sharing options...
garyrc Posted February 8, 2013 Share Posted February 8, 2013 That narrow rectangular opening right in front of the woofer, is that some sort of phase plug for the horn? Changing the size of that rectangular opening was an improvement PWK made in the Khorn in about 1963 (I think). I think he made the opening smaller. Quote Link to comment Share on other sites More sharing options...
coolhandjjl Posted February 8, 2013 Author Share Posted February 8, 2013 Thanks for the replies. I don't have a K Horn, but I am trying to learn about speaker design. Quote Link to comment Share on other sites More sharing options...
coolhandjjl Posted February 9, 2013 Author Share Posted February 9, 2013 ...The Bass bin has no phase plug.. I guess Phase Plug is probably not the right term. Probably more like "slotted horn throat opening" or something like that. But I have seen woofers in horns that fill the areas not exposed by the slot with two pieces of carved out solid extruded insulation so the gap from the woofers cone sections that are blocked via that slot remains constant from the woofers edge to the exposed area. I've also seen wood discs floated over the slots center like a true phase plug. But most of the time, I see the connection between a woofer and a horn is just a plain slotted opening (some quite wide, to almost the ends of the cone, others quite narrow.) Is the abscence of a true phase plug due to the bass wavelengths being so long that a phase plug is not necessary or that effective? Quote Link to comment Share on other sites More sharing options...
Don Richard Posted February 9, 2013 Share Posted February 9, 2013 That's the throat of the horn. Phase plugs are used to stop destructive interference due to path length differences between the edge of the diaphragm (cone) and the center of the diaphragm. The cone of the woofer and the size of the throat is small compared to the wavelength so no phase plug is needed. Quote Link to comment Share on other sites More sharing options...
coolhandjjl Posted February 9, 2013 Author Share Posted February 9, 2013 That's the throat of the horn. Phase plugs are used to stop destructive interference due to path length differences between the edge of the diaphragm (cone) and the center of the diaphragm. The cone of the woofer and the size of the throat is small compared to the wavelength so no phase plug is needed. A 40Hz wave is about 28', so whether it comes from the center, or wigggles in from the edge, the diff is only several inches, it's inconsequential compared to the total lenght of the wave, right? A 15,000kHz wave is about 1", so if the wave is coming from the edge of a 4" diaphragm, having that bounce around inbetween the diahragm and the driver's exit, now it does matter and it will interfere with some shift in phase causing a cancellation? I think I've got it! Quote Link to comment Share on other sites More sharing options...
ZAKO Posted February 9, 2013 Share Posted February 9, 2013 In the JBL cohearent phase plug,,for the high frequency,,all 4 anular slits are designed to be in phase,, Woofers do not need this in a horn,,But the Klipsch 3" x 13" is designed to help the woofer to reach up to 530 hz,,Where before in the larger slot 6"x13, it barely made it to 350 hz Quote Link to comment Share on other sites More sharing options...
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