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Doubling top boxes for FOH?

Discussion in 'Live Sound [BG]' started by Daedraziel, Dec 1, 2016.


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  1. Daedraziel

    Daedraziel

    Aug 19, 2013
    Toms River NJ
    Looking for some input about an idea that was suggested to me about getting more to the front of house.
    Current setup is a pair of EV ZLX-12p's over JBL prx118sp's. Pretty basic but good sounding setup for small to medium venues. The EV's are the best Bang for Buck speaker ive ever used and the subs (while cheap) do an adequate job of rounding out the low end frequencies without being earthshaking (there is such a thing as TOO MUCH BASS!!!!).

    We have been riding the EV's pretty hard for the last year or so and Im constantly seeing the "limit" on the back of the speakers during most nights. I know what they are capable of and I never let them distort...but...we need more FOH in some venues/events. Ive done a TON of homework on new speakers and I definitely want to stick with powered 12's since I like the way the mids/highs sound through them, very clear, but I cant justify making the guys spend $1500+ on a different (nice) pair of powered 12's just to get MAYBE another 10-20% of capability from them.

    So my idea is this to buy a t bar and another set of the EV's and put 2 of them over each sub like so
    ChoosingPA_05.jpg

    I realize that this picture is not accurate to what I'm using but it gets the idea across. In my mind I am substantially adding front of house capability and coverage, while being able to back off the levels of the tops so they don't limit. Also they could double as a matching set of floor wedges when we do a massive upgrade or use sound reinforcement guys for big events/venues.

    My first thought is weight...at 34lb's a piece, thats 68lbs suspended on a T-bar balanced on a steel sub pole.

    What are your thoughts? any feedback is appreciated.
     
    Last edited: Dec 1, 2016
  2. s0c9

    s0c9 Supporting Member

    Jan 9, 2014
    Ft.Worth/Dallas
    1964 Audio artist, Fractal Audio Beta Tester
    Should work.. but make sure you splay the tops.. angle in different directions (turn them away from each other), so you don't get audio artifacts from 2 speakers producing the exact same audio..
     
    kittywithabanjo and walterw like this.
  3. walterw

    walterw Supportive Fender Gold Supporting Member Commercial User

    Feb 20, 2009
    alpha-music.com
    right;

    if a guy in the crowd gets the sound full blast from both boxes and one is slightly farther away than the other, he'll get phasing/comb filtering weirdness.

    turning the inner ones in and the outer ones out so they each cover their own zone is the way to do it.

    (that may in fact kinda defeat your stated goal of doubling the boxes to make them louder; you might indeed be better off just getting more powerful tops.)
     
    s0c9 likes this.
  4. s0c9

    s0c9 Supporting Member

    Jan 9, 2014
    Ft.Worth/Dallas
    1964 Audio artist, Fractal Audio Beta Tester
    Hehe.. I was going to go there, but the OP stated he didn't want to go down that path..
     
  5. walterw

    walterw Supportive Fender Gold Supporting Member Commercial User

    Feb 20, 2009
    alpha-music.com
    the paths before us are not always the ones we want to go down.
     
    derrico1 and s0c9 like this.
  6. Daedraziel

    Daedraziel

    Aug 19, 2013
    Toms River NJ
    This is something I did not think about and the reason I asked. I kind of figured the idea had its downsides as I actually have only seen this setup once many years ago with passive 10inch Yamaha boxes.

    Actual floor coverage is certainly an issue in some rooms but I don't like the idea of a wierd or mushy sound anywhere in the place. Even if the tops were nearly butted up against each other i don't know how it would sound.

    Would it pay off to experiment and buy the bracket ($30) and give it a shot with a single stack? Like everyone else, I'm just trying to get more without spending a fortune...though it sounds like it may not work out that easily.

    Thanks for the input so far btw!
     
  7. RoadRanger

    RoadRanger Supporting Member

    Feb 18, 2004
    NE CT
    The "right" way to couple a pair of tops is to stack them with the top one upside down so the two horns are as close together as possible - Difficult to do with many modern cabs. OTOH if you put them side-by-side as close together as possible the comb filtering really isn't noticeable to vast the majority of the audience.
     
  8. JohnMCA72

    JohnMCA72

    Feb 4, 2009
    I have multiple ZLX-12Ps that I use as mains, wedges, side-fill, etc. & use them that way sometimes, with wide or narrow splay depending on the coverage & SPL needed.
     
  9. RoadRanger

    RoadRanger Supporting Member

    Feb 18, 2004
    NE CT
    Lots of "book learning" here on TB vs actual experience ;) .
     
  10. derrico1

    derrico1 Supporting Member

    Apr 12, 2005
    Charlottesville, VA
    OP, For the cost of a T-bar, you can set up your current pair of EVs and judge for yourself whether comb filtering effects are an issue worth worrying about for you.
     
    RoadRanger likes this.
  11. RoadRanger

    RoadRanger Supporting Member

    Feb 18, 2004
    NE CT
    Or just put them up on your porch or car for free :) .
     
    Remyd and s0c9 like this.
  12. thekyle55

    thekyle55

    Mar 14, 2012
    I would set the pair you have up side by side, play some music through them, and have someone turn one on and off and see if the extra volume is worth it. I've done similar things, and it's never been worth it to me, with the extra set up time, weight, and pack space required.
     
  13. derrico1

    derrico1 Supporting Member

    Apr 12, 2005
    Charlottesville, VA
    That's definitely a fair enough test, RoadRanger. OP: if you don't mind whatever phase interference, reflections, and coupling effects result from putting 2 speakers a couple feet apart on your car roof, it's probably safe to say you wouldn't even notice any phase interference from mounting the pair in-air at a similar distance on a T-bar. Especially once the crowd fills the room. :thumbsup:
     
  14. musicman7722

    musicman7722 Supporting Member

    Feb 12, 2007
    York, ME US of A
    Another approach if you go this route is to put instruments in one top per side and vox in the other. I have read that this really can make a difference. I was in a band once and the guitar guy was crazy over trying this.
     
  15. Ulf_Hansson

    Ulf_Hansson

    Apr 15, 2014
    To me that sounds like asking for trouble...
     
  16. musicman7722

    musicman7722 Supporting Member

    Feb 12, 2007
    York, ME US of A
    Probably
     
  17. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge
    1 pair of high performance 90 degree tops would be a far better choice. Or two pair of 60 by 40 trap boxes.

    I have two systems that 'splay array'. QSC K12's in one and some older coax PAS install boxes. They sound great but run out of gas at a point. They actually do sound great too. Time aligned using SMAART they are more like really great hiding as opposed to PA... The K12's don't splay as well and they really aren't as sweet as the PAS boxes but they do go loud loud. IMO for larger outdoor settings, I am just getting by. The interaction between the boxes is very noticeable to me even after careful aiming. Particularly with the K12's. The pass boxes are better closely but not tightly packed. That yoke thing up above is a joke when it comes to even coverage from boxes like those pictured.

    This is my number one priority going into the next season. High performance point source tops. Older Renkus TRAP or EAW or JBL Tour Array (489x series) are at the top of my list... All boxes that were designed for tight packed splay array. This is older passive but professional stuff. It is heavy, large but all this stuff kicks butt on the the level of box I'm using now. My QSC's will make better than fine monitors..

    I can say that for many outdoor gigs I did last summer, 1 K12 on a pole over 2 KW-181 subs got pretty darn loud and sounded pretty nice. There were 3 or 4 though where I really felt I needed more. I never got a complaint. Lot's of compliments in fact. ...but I could hear it, the guys I trust to mix for me could hear it and so it's upgrade time.
     

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