Rigging for speakers by Darren Seagren
JBL VERTEC 4889
JBL’s passive touring line array system for mids and highs
Individual box weight: 160 Lbs
Bumper weight: 100 Lbs
The Vertec Bumper is made of T-6061 aluminum and can support a total of 16 Vertec 4889 boxes with a design factor of 7:1.
The hinges between the boxes are made of high grade alloy steel. A simple, non-adjustable hinge is used in the front, while a hinge with holes cut at various distances from the hinge is used to gain the desired degree of angle on the back. Stainless steel quick release pins are used to retain the desired angle on each box
Individual Box Weight: 123.2 Lbs
The K2’s bumper consists of 2 parts: the K2 Bump, and the K2 Bar. Both the K2 Bump and the K2 Bar are comprised of high grade steel with an anti-corrosion coating. When combined, The K2 Bump and the K2 Bar are capable of holding 24 boxes on a 4:1 design factor. The K2 line array uses a non-adjustable hinge in the front, however, it uses an innovative angle pinning system on the rear. The audio engineer can select the desired angle easily by selecting it on the angle plate. What makes this stand out, is that it is done weight, and tension, free. After the engineer has selected the desired angle and pinned it, the boxes will automatically lock together.
L’Acoustics’ V-DOSC System
Individual Box Weight: 238 Lbs
Bumper Weight: 135.6 Lbs
The V-DOSC bumper is made of high grade steel and can fly 16 cabinets with a design factor of 5:1.
The V-Dosc system is a full system, capable of lows at 18Hz, and highs in the 18KHz range. The line array can still be supplemented with the V-Dosc subwoofers as well, for added low end.
The system used to join the cabinets is simplistic. A steel bar is extended downward from one cabinet to another, and is secured in place by a large U bolt. This bar secures the back end of the boxes together. A flytrack is incorporated on the side of the cabinet. Angle straps, a simple bar of different lengths, are used to connect the boxes and obtain the desired angle. One thing to note is that the system used for obtaining the angles is slightly rudimentary. As such, 2 ratchet straps are used from the bottom box to the top of the bumper, to pull the angles as tight as possible.
Meyer Sound’s Mica Line Array
Individual Box Weight: 150 Lbs
Bumper Weight: 113.5 Lbs
The Mica bumper is made of steel and can fly either 22 boxes on a 7:1 design factor, or the manufacturer states that a reduction in design factor to 5:1 can allow 25 boxes to be flown.
One thing that a rigger should note is the combined weight of the bumper and 25 boxes is roughly 3900 Lbs. While still less than 2 tons, if shock load is added by bumping the motors, or the weight is not evenly distributed across both motors, a one ton motor could easily fail! Meyer Sound has made the attachment pin hole large enough to accept a ¾” anchor pin shackle, so 2 ton motors may be used to lift the large array if you are approaching 25 hanging boxes.
The Mica is a full, self powered midsized system. It is capable of lows to 60Hz, and highs to 18kHz.
The pinning system used to adjust splay angle on each box is simplistic, yet innovative. The Mica has an adjustable plate on the back hinge of the box. The angle plate allows the splay angle to adjust from 0 – 6 degrees. While this is fairly standard, the Mica also has an adjustable hinge on the front, which allows for either a 0 or 7 degree angle. If the front hinge is set to 0, the total box splay angle achieved can be 0 – 6 degrees only. However, if the front hinge is set to 7 degrees, the total splay angle can combine with the rear angle to allow for 7 – 13 degrees of splay angle.
Meyer Sound’s M’elodie Line Array System
Individual Box Weight: 62 Lbs
Bumper Weight: 36 Lbs
The M’elodie bumper is capable of flying either 18 cabinets on a 7:1 design factor, or a maximum of 25 cabinets on a 5:1 design factor.
The M’elodie line array system is a smaller mid-range system, and is capable of lows to 70Hz, and highs to 18 kHz. The system is self powered and is capable of a great coverage, but the throw is not as nearly as far as the Meyer Mica system.
The reduced weight of the cabinets makes these very versatile. While impractical, a full array can be suspended from a single one ton motor without fear of motor failure. The pinning system on the cabinets is designed with ease of pinning in mind. The front hinge stays static, and is designed as a pivot point only. The box splay angle is attained through an adjustable plate on the rear hinge. Angles 0 – 11 degrees may be attained through the use of the adjustable hinge plate.
The M’elodie array travels in sections of 5 cabinets on a castor board. With this, the reduced weight of the cabinets, and that the array is self powered, this system is idealistic as delays in a convention center. Power and signal to the array can easily come from a catwalk, which keeps the floor space underneath the array clean. The reduced weight allows for an array of 5 boxes to be suspended from a single CM Prostar motor. This lowers the rental cost of motors, and can free up space in a delivery truck (four Prostar motors can fit in the same space as two ½ ton Lodestar motors.