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Porn Horn |
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nuggets ![]() Registered User ![]() Joined: 03 May 2005 Status: Offline Points: 2 |
![]() ![]() ![]() ![]() ![]() Posted: 03 May 2005 at 12:00pm |
Hi, thinking of building MT122s with the porn horns. Would there be any
difference in placing the two mids on the bottom of the cabinet and the
top on top? Also do the porn horns make much of a difference compared
with the original design???
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Jez_Ultra ![]() Registered User ![]() Joined: 26 February 2004 Location: United Kingdom Status: Offline Points: 334 |
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The main benefit of the Porn Horn is the inclusion of the phase plug, which simply means that you'll be able able to cross over into the compression driver much higher - giving you a much cleaner sound.
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james folkes ![]() Old Croc ![]() Joined: 08 January 2005 Location: United Kingdom Status: Offline Points: 3064 |
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as i understand it the horn flares of the two mt122 flares are designed
such that with the separation of the compression driver there is minimal lobing effect between them. furthermore i think the cabinet trapezoid angle is also matched to the horn flare so that they can be arrayed. having the compression driver in the middle also presents more of a point source in the mid high frequencies, but makes them more suited to sitting on a tall bass stack to aid projection. balancing these factors with the dispersion characteristics of the porns is i think the issue. there is a thread showing a trapezoidal cabinet construction method for the porn horn with a single compression driver entitled "porn addick" in the slightly older bits of the new projects forum. it goes a bit off-topic as you will see and unfortunately dispersion is not discussed. james. |
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nuggets ![]() Registered User ![]() Joined: 03 May 2005 Status: Offline Points: 2 |
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Had a look at that porn addick thread: http://www.speakerplans.com/forum/forum_posts.asp?TID=1620&a mp;a mp;KW=porn+addick It says 2 X 12" horns but only has one in the design. Just add another to it? To the top of the cabinet or botton??? What's 'lobing'? Edited by nuggets |
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james folkes ![]() Old Croc ![]() Joined: 08 January 2005 Location: United Kingdom Status: Offline Points: 3064 |
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lobing is the result of overlap from multiple sources which don't array
happily. the trapezoidal walls of the mt122 cab mate with the vertical flare components to ensure that as you wander across the soundfield the level is mostly uniform, minimising the effects of destructive wave superposition. the separation of the two mid components using the compression driver ensures the same behaviour between these two horns, where the effect would be more pronounced as you changed height or distance away from the stack. the effect can be very noticeable at low mid frequencies where there are distict 'quiet spots' for some notes infront of the stack. this is my understanding and experience of the subject. as for predicting the dispersion patterns and the constructive and destructive superposition of the porns, that's so far out of my league it's not even funny. nevertheless it will be crucial in determining how to best locate the porns in your boxes, so keep asking. it does matter, and someone will know. james. |
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tendril ![]() Registered User ![]() Joined: 22 July 2004 Status: Offline Points: 334 |
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Why not make 1 with top and mid and 1 with just the mid. Then you could
change the setup depending on how high your bass stack is, with the
single porn either on top à la MT122 or underneath for use on a shorter
stack.
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Tendril
A mistake is a mistake only if one learns nothing from it. |
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