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Thread: SR pros on this forum

  1. #31
    Senior Member JuniorJBL's Avatar
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    Quote Originally Posted by Zilch
    If the two center ones are playing mono and both aimed forward, they'll majorly interfere with each other.

    Consider the directivity spec. Horizontal coverage (-6dB) is 70 degrees.

    I'd keep the centers horizontal, woofers at center, rotate the mid/high horns into the normal vertical position, angle them out at 67.5° with respect to each other (total included angle), and then tilt them down 25° to 30°. The vertical coverage (-6dB) is 50°. There seems little point in bouncing half of that (500 Hz to 16 kHz) off the ceiling other than to compound the problem with spurious reflections....
    Currently they are set in a "v" across the center at about 30 deg. They also tilt down about 25-30deg.
    The woofers are on the outside so to change them I would have to take them down and change the rigging points or swap one for the other. either way I have to take them down to do anything with them.

    I will try to draw a diagram so all can understand what is happening.
    Thanks All

  2. #32
    RIP 2011 Zilch's Avatar
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    Quote Originally Posted by JuniorJBL
    I will try to draw a diagram so all can understand what is happening.
    Thanks All
    Are the rotatable mid/high assemblies vertical or horizontal, that is, is the tweeter above the mid or to the side?

  3. #33
    Senior Member JuniorJBL's Avatar
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    orientation

    Quote Originally Posted by Zilch
    Are the rotatable mid/high assemblies vertical or horizontal, that is, is the tweeter above the mid or to the side?
    Vertical

  4. #34
    RIP 2011 Zilch's Avatar
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    O.K., so when they mounted the cabinets horizontal, they rotated the mid/high back to the vertical orientation. I think the problem is that the angle is too small, and the mid/highs are cross-firing at the center and interfering with each other.

    You can test this by rotating the mid/high assemblies back to the horizontal, which would require less of an angle, as the dispersion angle would be 50° as opposed to the present 70°. Work with only the centers playing to get their problem defined.

    The design was engineered, apparently. Can you consult with the original designer?

    "What were you thinking, dude?"

    Are the side speakers at the front, or up behind the same screens in the angled sections? If they're all up there together, I agree you want to horizontally array them all as you are thinking. I see your choices of coverage angles as 200° (4 X 50°), 240° (2 X 50 + 2 X 70°), or 280° (4 X 70°). I'd keep the two center ones running mono, probably.

    I'm not there, so I may have my head in a dark place about this, of course....

  5. #35
    Senior Member Akira's Avatar
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    whenever you combine multiple line array trapezoidial speakers in a cluster, you must mount them vertical. whenever you fly line array traps, you should position the speaker with horn down. be concerned with horn placement only, aiming all HF drivers in an arc for a combined even wave length coverage; the trapedoial design will naturally take care of the radiating quality of the other drivers. trapezoid designs are not built that way to look cool. they are built that way because the shape of the enclosure is designed to work in certain configurations. even in a front load cabinet, a trap design will throw further than a rectangular box. line arrays, especially with two or more identical drivers will also have better throw characteristics. this is in fact why a trap design and a vertical array go hand in hand.
    DO NOT place the cabinets side by each or even separated by 5' aimed in the same plane.
    p.s. assuming all components are firing correctly, go for a physical solution...the third rule of sound: Correct physical problems physically; correct electronic problems electronically. No amount of technical brilliance can make up for a physical solution or have the impact of proper physical driver alignment.
    finally, what the SR industry now calls "line array" is in fact a horizontal dispersing enclosure with a small tightly controlled vertical beam. this new breed of enclosure is designed to fly vertical from top to bottom, sometimes in a configuration 20 high and only one wide! again, messing with this configuration and placing them side by side would totally destroy the acoustic alignment of the cluster.

  6. #36
    Senior Seņor boputnam's Avatar
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    Quote Originally Posted by Zilch
    I'm not there, so I may have my head in a dark place about this, of course....
    But, Zilch - how could we tell...?
    bo

    "Indeed, not!!"

  7. #37
    Senior Seņor boputnam's Avatar
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    Quote Originally Posted by Akira
    DO NOT place the cabinets side by each
    Great post, Akira.

    Tho', you might want to revise the quote, to avoid any confusion...
    bo

    "Indeed, not!!"

  8. #38
    Senior Member JuniorJBL's Avatar
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    The person who...

    I do know who installed but they nolonger work for the company.

    Also I found out that one HF driver was disconnected after they first installed them.

    This leads me to belive that they had this problem and were looking for a fast fix.

    I am not sure what you mean by "Do Not place them side by each"
    Please bring clarity to my world.


  9. #39
    Dis Member mikebake's Avatar
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    SR4735, (sound reinforcement) VS3115 (venue) and CS3115 (cinema) are all basically the same unit. I have four of them and they are worth preserving in your venue; the vocal intelligibility with them can be quite excellent, as can LF reproduction when used in multiples. It is a good box; hope you keep plugging away; sounds like you are close.

  10. #40
    Senior Member JuniorJBL's Avatar
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    VS3115

    Yes the sides sound really good, so I do want to keep going towards the goal

  11. #41
    RIP 2011 Zilch's Avatar
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    Says 3115 may suitably be horizontal mounted:

    http://www.jblpro.com/pub/manuals/Install_guide.pdf

    Says sides should be delayed:

    http://www.jblpro.com/pub/install/V_SP_Array_guide.pdf

    See Fig. 3 & 5 here:

    http://www.jblpro.com/ae/pdf/AE_PD%2...%20Rev%20C.pdf

    More of general interest, but see last photo:

    http://www.jblpro.com/pages/Reprint_LowRes_NoMarks.pdf

  12. #42
    Senior Member Akira's Avatar
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    Quote Originally Posted by boputnam
    Great post, Akira.

    Tho', you might want to revise the quote, (side by each) to avoid any confusion...
    that's my "Canadian" coming out...a joke on the french.
    whenever we do a gig with them Quebec guys they tell us, "set all those speaker over dere side by each"

    JuniorJBL: of course it was meant side by side

  13. #43
    Senior Seņor boputnam's Avatar
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    Quote Originally Posted by Akira
    whenever you combine multiple line array trapezoidial speakers in a cluster, you must mount them vertical. ... DO NOT place the cabinets side by (side)...
    Hey...

    Yea, I got that, but the last statement, above, seems to contradict the first. 'splain...?
    bo

    "Indeed, not!!"

  14. #44
    Senior Moment Member Oldmics's Avatar
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    Yeah,I"m with Bo on this one!

    Respectfully Akira some clarification on your terminlogy is requested.

    What is a "combine multiple line array trapezoidial speakers in a cluster"?

    Are you referring to multiple trap enclosures with all of its componets oriented in the same plane? and then wrapped into a single cluster?

    If my above statement is correct then the multiple enclosures will not act as a line array system.It would be a spherical radiating enclosure that has its componets aligned in the same plane (be it horizontal or vertical)

    Or what you refer to in a later post as a "vertical array".

    I guess my confusion lies in the intermingling of the term "line array" with trap enclosures.

    You also make the comment "a trap design will throw further than a rectangular box."

    Are you talking individualy or multiple enclosures?The "throw" charactoristics are defined thru sound pressure levels which are calculated from the use of multiple enclosures,enclosure style (if line array-focusing of the boxs) and hang heigth.

    There is no difference in "throw" when comparing one rectangular box to one trap enclosure.This takes into account that the same componets and componet configuration loading (horn ,front load,etc) is utilised and only the exterior cut being different.

    I think we are thinking on the same page with only the dialect being different.

    Just looking to ease mine and Bo"s confusion.

    Best regards,Oldmics

  15. #45
    Senior Member edgewound's Avatar
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    Nice Job

    Quote Originally Posted by Oldmics
    Yeah,I"m with Bo on this one!

    Respectfully Akira some clarification on your terminlogy is requested.

    What is a "combine multiple line array trapezoidial speakers in a cluster"?

    Are you referring to multiple trap enclosures with all of its componets oriented in the same plane? and then wrapped into a single cluster?

    If my above statement is correct then the multiple enclosures will not act as a line array system.It would be a spherical radiating enclosure that has its componets aligned in the same plane (be it horizontal or vertical)

    Or what you refer to in a later post as a "vertical array".

    I guess my confusion lies in the intermingling of the term "line array" with trap enclosures.

    You also make the comment "a trap design will throw further than a rectangular box."

    Are you talking individualy or multiple enclosures?The "throw" charactoristics are defined thru sound pressure levels which are calculated from the use of multiple enclosures,enclosure style (if line array-focusing of the boxs) and hang heigth.

    There is no difference in "throw" when comparing one rectangular box to one trap enclosure.This takes into account that the same componets and componet configuration loading (horn ,front load,etc) is utilised and only the exterior cut being different.

    I think we are thinking on the same page with only the dialect being different.

    Just looking to ease mine and Bo"s confusion.

    Best regards,Oldmics
    Nice clarification Oldmics
    Edgewound...JBL Pro Authorized...since 1988
    Upland Loudspeaker Service, Upland, CA

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