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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => SR Forum Archives => LAB Subwoofer FUD Forum Archive => Topic started by: Bosstard on October 13, 2004, 09:04:24 pm

Title: Stacking Vs. Flying subs
Post by: Bosstard on October 13, 2004, 09:04:24 pm

Hello everyone,
I have been trying new things for a while now, but I would like to hear what you guys think. What is the best to set up my VerTect subs? Should I stack them on either side of the stage or fly them? Which way will provide more bass and sound better. Also, are their any amp reccomendations for the VT4880's? I use QSC 9.0's currently. IS there anything better suited for them. Thanks!

Steven.

Title: Re: Stacking Vs. Flying subs
Post by: Phillip_Graham on October 14, 2004, 12:45:10 pm

Steven B wrote on Wed, 13 October 2004 21:04

Hello everyone, I have been trying new things for a while now, but I would like to hear what you guys think. What is the best to set up my VerTect subs? Should I stack them on either side of the stage or fly them? Which way will provide more bass and sound better. Also, are their any amp reccomendations for the VT4880's? I use QSC 9.0's currently. IS there anything better suited for them. Thanks! Steven.

There are advantages and disadvantages to both options:

Ground Advantages
*Easier Setup
*More output (because of boundary loading)
*Can greatly reduce power alley depending on placement
*Short runs to amplifiers

Ground Disadvantages
*Sightlines
*Stage spill
*Little vertical directivity
*Only sum directly in phase with the tops at a few select points.

Flown Advantages
*Vertical directivity
*Less stage spill (with correct placement)
*Good phase summation with the nearby tops for majority of audience.
*Sightlines

Flown Disadvatages
*Points, Motors, Logistics
*Slightly less output
*L/R arrays will still have power alley effects.
*Long cable runs (unless you fly the amps).

Additional comments
If I had to choose between groundstacked L/R and flown L/R, I would pick flown any time possible.  If I could do a more advanced ground array, then it would not be as clear a choice.

If you are practiced with doing phase alignment in Smaart (something I recommend taking the class to learn), and have the setup time, you can get pretty good alignment for most of the audience with the PA in the air and subs directly below.  If your trim heights are similar most of the time, you can even find this delay time in the shop and just trust it.

If you are not Smaart proficient, you can fly them adjacent to the tops, and trust JBL's recommended delay time for this setup.

There are many other more advanced sub arrays that can be tried depending on specific show settings.

Horizontal line arrays, and split vertical dipoles are two of my personal favorites, if you would be interested in hearing about how those work.

Title: Re: Stacking Vs. Flying subs
Post by: Bosstard on October 16, 2004, 07:42:44 pm

Thanks for the info. I tihnk Im going to be flying my subs with the large arena's Im going to have to be covering. It seems like it will work the best for my rig. Anyone esle have comments?