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Thread: About dance stacks..

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  1. #1

    About dance stacks..

    Ok, here's a little background : I've built a few sub enclosures; a Scoop for mobile gigs and a 186/1850 which wasn't functional but a fun build anyway... I don't currently have all the necessary tools (there's space to build though, but no venue) or the materials, not to mention resources to build a dance stack but I'm a dreamer..

    OBS: For those of you who don't know what a dance stack is, it's basically a tower of crossovered speakers; usually a 3/4 way system. It's sort of outdated (speaker)design-wise but some clubs (such as Stereo in Montreal, and Berghain) make use of it because it has certain sonic qualities (SBS for instance) and an unparalleled appereance (such as the version by Funktion One)

    So, I've been designing these things on paper over the course of years (the RLA, GSA, SBS and Funktion One plans are a trade secret I presume) and also lurking a bunch of discussions related to this matter. Basically, the only option would be to build one which is a) expensive and b) time consuming because there would be a huge amount of woodwork and A/B testing of the components.

    One downside of a dance stack is that it isn't really mobile... most of the stuff is meant for fixed installation.

    Well, anyway, here's my try at designing one..



    To break it down :

    1. The very bottom end is a *slightly* modified WSub (edit:sorry, WBin ->EDIT : no, sorry, actually this) which I designed from the top of my head (it has an extension too)
    2. Low frequency stuff is handled by a 186/1850 clone (the punchy sort of bass)
    3. The 15" Scoop takes care of the midrange. I could've designed a dual 15" Scoop which wouldn't be a bad idea although it adds to the overall weight (if that's a factor) and height of the system.
    4. Then there's a tweeter array for the high frequencies. There's a ceiling version as well as a stack version.

    To be realistic, the materials for this system (2 stacks) would cost about 4-6k with drivers (edit : well maybe a bit more, say, 10k) Then there are amplifiers of course.

    I personally think the low sub (Qi218/215) would need to be redone somehow (the *compression* chamber is huge compared to the rest of the path...the driver would most likely break) and like I said before, I don't have the resources to build one... maybe someone will be inspired by this.

    Anyway, tell me what you think!

    EDIT : Nevermind the fancy (product)names I came up with in the middle of the night... it sort of looks more professional that way

    EDIT2 : Note that I'm not exactly the best technical drawer out there.. and I do know how to use a CAD (it's been a long time). Designing stuff with one though feels like trying to win a game of CS.

    EDIT3 : And I do enjoy feeling like James Bond, microfilming documents and stuff..

    EDIT4 : At times I get lost in the speakerplans.com forums.. maybe I should've posted this there instead
    Last edited by efinque; 11-02-2017 at 10:08 AM. Reason: edited

  2. #2
    Like you said, obsolete. Visually impressive, but overly complicated and not very good sounding.
    Bill Fitzmaurice
    Bill Fitzmaurice Loudspeaker Design
    www.billfitzmaurice.info/forum

  3. #3
    Quote Originally Posted by Bill Fitzmaurice View Post
    Like you said, obsolete. Visually impressive, but overly complicated and not very good sounding.
    I did find an odd looking Bertha in a 3D rendered (GSA clone) stack, the dual 2x18" was (edit : seemed) horizontal instead of vertical..

    EDIT : Another thing that came into my mind is that I've seen full-range scoops with small sealed tweeters in them..

    EDIT2 : The system could also benefit from, for example, an 8" midtop.. now the top-end looks like someone placed a small alarm clock on top of a bookshelf (edit : looks-wise).. this is mainly because the 15" isn't really accurate in the high-midrange. ie. I've heard a d&B Tech Cromo8 in action and it's an impressive little speaker, albeit active, but their designs are simple, powerful and lightweight.

  4. #4
    Scoops are one of the worst speaker configurations possible, as they have a deep response notch where the front and rear waves meet 180 degrees out of phase.
    Basically, the only option would be to build one which is a) expensive and b) time consuming because there would be a huge amount of woodwork and A/B testing of the components.
    That option is also obsolete, rendered so 20 years ago by speaker modeling software.
    Bill Fitzmaurice
    Bill Fitzmaurice Loudspeaker Design
    www.billfitzmaurice.info/forum

  5. #5
    Quote Originally Posted by Bill Fitzmaurice View Post
    Scoops are one of the worst speaker configurations possible, as they have a deep response notch where the front and rear waves meet 180 degrees out of phase.
    That option is also obsolete, rendered so 20 years ago by speaker modeling software.
    For an outdoor application; yes, but for indoors there's a lot more stuff that needs to be taken into account, ie. the target venue would need to be modeled in some weird, advanced physics modeling software that calculates reverberation etc.

    EDIT : As for the scoop issue, it's like the crazy uncle; you're not sure whether or not to invite him to a party but as soon as you "see" and hear one in action you're sold.

    EDIT2 : Also, I read somewhere that lifting a sub from the floor attenuates the sound by ~3dB... is this true? (I'm too lazy to try and I don't have a db meter..)

  6. #6
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    Quote Originally Posted by efinque View Post
    EDIT : As for the scoop issue, it's like the crazy uncle; you're not sure whether or not to invite him to a party but as soon as you "see" and hear one in action you're sold.

    EDIT2 : Also, I read somewhere that lifting a sub from the floor attenuates the sound by ~3dB... is this true? (I'm too lazy to try and I don't have a db meter..)
    I have seen and heard scoops plenty of times and just like anything Bose I am yet to be impressed. But never mind that, nobody uses a scoop for "midrange" because it's upper frequency response is just nasty, they're typically used for bass. I get the idea of a dance stack but just like F1's version you need some proper mids and highs to deliver something approaching the HI-FI sound these systems are supposed to deliver, something like a speakerplans MT102 or MT122 would work and look right IMO and give you the 4-way setup.
    Paul O'Brien
    Old Tech Guy
    www.Techott.com

  7. #7
    Quote Originally Posted by conanski View Post
    I have seen and heard scoops plenty of times and just like anything Bose I am yet to be impressed. But never mind that, nobody uses a scoop for "midrange" because it's upper frequency response is just nasty, they're typically used for bass. I get the idea of a dance stack but just like F1's version you need some proper mids and highs to deliver something approaching the HI-FI sound these systems are supposed to deliver, something like a speakerplans MT102 or MT122 would work and look right IMO and give you the 4-way setup.
    Obviously this guy does..

    EDIT : I also modified the low-end design by making the end part of the "throat" of the horn parallel to the side of the cab.. it looks more logical that way imo but I kept the original drawing (the both sides are meant to be identical anyway..) also the far side of the horn is now in a 45 degree angle which makes it (edit : the opening) wider. I've seen some builders omit the "scoop"-section of horn plans because it's sort of obsolete, although it looks cool.

  8. #8
    Quote Originally Posted by efinque View Post
    Obviously this guy does..
    Yes, but that guy doesn't know what he's doing. There's a big difference between throwing a bunch of cabs together and calling it a system and designing a system, starting with the individual elements. We acoustical engineers who actually design speakers for a living have a technical term that perfectly describes that sort of system: Clusterf*ck.
    Also, I read somewhere that lifting a sub from the floor attenuates the sound by ~3dB... is this true?
    No.
    Last edited by Bill Fitzmaurice; 03-09-2017 at 10:45 AM.
    Bill Fitzmaurice
    Bill Fitzmaurice Loudspeaker Design
    www.billfitzmaurice.info/forum

  9. #9
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    Quote Originally Posted by efinque View Post

    EDIT2 : Also, I read somewhere that lifting a sub from the floor attenuates the sound by ~3dB... is this true? (I'm too lazy to try and I don't have a db meter..)
    Here is a whole thread on the issue of flown/ground stacked subs with measurements: http://forums.prosoundweb.com/index....,158814.0.html

    Essentially the crowd is almost always (unless there is a human cannon) on the ground in half space and as such no matter where you put the subs vertically outdoors, you will get half space loading for the crowd. Possibly flown subs and high up bleachers may change that but for the most part it doesn't matter.

  10. #10
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    Quote Originally Posted by Coronaoperator View Post
    Here is a whole thread on the issue of flown/ground stacked subs with measurements: http://forums.prosoundweb.com/index....,158814.0.html
    Actually... The issue of unanchord subs is mentioned in that thread but so far not explored in detail, Newtons 3rd law. So i'd likely of picked it up from somewhere, not dreamed it up myself. I've still not seen dedicated maths to the subject. Especially to the accuracy of the speaker, transient response. Imagine a basket throwing itself forward as the cab has backwards movement, reaching the limits of the speaker earlier, the resistance in suspension, overshooting the magnet, bottoming out, with less air been moved. But the air will be getting moved backwards more so would the resulting air pressure not stay the same... I don't know, I'd like to read a lot more on this subject. [S]Other than the same old, comb filtering, half space, whole space, inverse square argument. A desire to move forward, not go round in circles[/S].

    Edit: actually i retract that last line, I'd still like to have a better understanding on those subjects... Strike through didn't work!
    Last edited by mitchiemasha; 03-10-2017 at 09:46 AM.

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