Factory Direct: Advancing the Art
Three years in design, McCauley antes up

By Jason Farris

McCauley’s MONARC MLA5 flown at the site.

In recent years, system engineers have been nearly universally attracted to line array sound reinforcement systems for their special ability to achieve nearly homogenous SPL over the coverage zone, while maintaining exceptional clarity over distance. As a result, in what has become a very competitive market segment, several new line arrays were introduced by various manufacturers during the past calender year. McCauley Sound was founded in 1979, and over the intervening years the company has become known for their “total control“ all-in-house approach to system engineering and manufacturing. Based in the company’s long history of industry breakthroughs, McCauley’s new MONARC™ line array technology appears to an immediate, legitimate challenger in the white hot line array wars.

MLA5 OVERVIEW

The MLA5 is a low-profile, axially symmetrical, three-way line array module based on McCauley Sound’s MONARC line array technology. Engineered to deliver high definition, high SPL sound reinforcement for a broad range of applications, the MONARC MLA5 offers sound designers a flexible tool for creating acoustically accurate coverage zones.

This article will explain the principles behind MONARC technology, the research and history behind it’s development. As the MONARC line array engineering project commenced nearly three years ago, McCauley Sound decided to first examine and profile every aspect of large format touring so the MONARC engineering team could develop a truly comprehensive perspective on the needs of the industry.

Accordingly, the McCauley MONARC MLA5 is more than a summation of relevant technologies. Instead, it is a engineered solution to the specific acoustic and ergonomic problems the company was able to identify with help from the “real people” of the industry.

The MLA5 addresses several shortcomings of early line-array designs. The MLA5’s internal compliment, and it’s defining technology, the Intercell Summation Aperture™ (ICS Aperture), is a certain departure from conventional approaches.

From a physical, practical standpoint, the MLA5’s enclosure and rigging hardware are designed to have the ability to be arrayed with up to 10° splay between cells, without the need for any special hardware or multiple enclosure designs.

Capable of being configured for the broadest possible range of applications, the MLA5 may reduce the need for unnecessary and redundant product in a touring company’s inventory.

BASIC LINE ARRAY THEORY

The line array phenomenon was described by Olsen in 1957 as “a group of radiating elements closely spaced and operating with equal amplitude and in phase”. The assumption is that all of the elements must be stacked above or below each other, creating a vertical “line”.

The simplest example of a line-array performance is the narrowing of vertical pattern when two or more transducers are “stacked” together. However, this effect is only applicable when the spacing of the individual sources is small, as compared to the lowest frequency it will be reproducing. This relationship is represented by the equation:

FL=(1130 x 12) / EC

FL = upper frequency limit,
EC = distance between emissive centers (in inches)

Above this frequency, the dispersion pattern starts to exhibit lobing and no longer acts as a singular sound source. Below this frequency, the individual drive elements will combine to from a single wavefront, which is the primary determining factor in defining line array behavior. The primary advantages of this arrangement are that the combined drivers exhibit an increase in vertical directivity (the vertical dispersion narrows) while not affecting the horizontal coverage pattern as an extension of the nearfield.

The differences between near field and far field are important to distinguish when discussing line arrays. Simply, the far field begins at a distance between eight and ten times the largest dimension of the array, however this transition is not at a fixed point, it is frequency dependent. For example, to calculate the transition point for an array of twelve MONARC cells, 4.25m(13.9ft) tall, one would use the following equation:

DA =(HA^2)(FR)/690 = TA

DA= Distance from Array, HA = Height of Array
FR = Frequency of Interest, TA = Transition Area

In this case, at 500Hz, the far field starts at approximately 6.52m(21.4ft), at 1000Hz, it is 13m(42.6ft), and at 8kHz, it would be 104m(341ft) from the array. The unique purpose of a line array is that while the listener remains within the near field, the sound intensity only drops -3dB per doubling of distance, but once in the far field, SPL will drop at the normal -6dB per doubling of distance.

Advantages of this approach are that combined drivers exhibit an increase in vertical directivity (this means vertical dispersion narrows) while not affecting horizontal coverage, in extension of the near field. This is the defining design principle of the MONARC MLA5.

MINIMIZING MIDBAND DISTORTION

During the research phase of MONARC development, it became clear that an alternative approach to midrange reproduction was needed. Severe distortion effects were discovered and measured among the line array offerings of the time. McCauley Sound engineers discovered that the smaller 6-8in midrange drivers, while exhibiting a few desirable “hi-fi” characteristics, were too fragile, and were producing an unacceptable level of comb filtering, harmonic distortion, and general lobing artifacts.

Polar #1…the horizontal response of a typical line array MF 6.5”

Multiple smaller drivers were used for the midrange compliments of many earlier line array systems, due to the theoretical spacing needed in the vertical plane in order to achieve the desired summation effects. McCauley Sound also began with this approach. Assuming that a loading consisting of four small drivers would work correctly in the vertical plane, McCauley Sound engineers started by measuring the performance of 6.5in drivers to determine the best geometric arrangement to achieve a constant dispersion pattern in the horizontal plane. Our premise assumed that once a smooth, constant horizontal pattern was achieved, it could be maintained once the drivers were arrayed in the vertical plane.

Polar #2…the horizontal response of the MONARC HX32

Several surprising problems appeared during this development stage. The first problem was that regardless of the horizontal angle of the drivers, lobing was present at levels as low as 800Hz and became rather severe as they reached their upper limit goal of 1500 Hz (See Polar #1). This upper frequency was selected as a goal because, even with modern high order filtering networks, midrange devices still contribute significant SPL levels at 1500Hz when crossed over in the anticipated 1000Hz-1200Hz range. The second obstacle was the degradation of frequency response within individual driver units. Figure #1 shows the on-axis frequency response of the test drivers.

Figure #2 shows the typical on-axis response of a pair of drivers, as they would be loaded into the design with the angled baffle.

What is important to note is the significant variations in the curves, whose response became progressively worse as the angle changed. Because the primary function of a line array is to provide seamless, even, and exceptionally consistent coverage, a design using the conventionally accepted small midrange drivers would clearly not meet these goals.

Other concerns included the significantly large distortion products the drivers produced, and just as problematic, the extremely limited dynamic range these drivers exhibited. At an SPL level of 110dB measured at one meter, a pair of the conventionally applied 7in drivers were, in the most optimistic case, producing 3% to 4% harmonic distortion.

The drivers were also showing significant amounts of power compression at this level (typically 3 to 9dBSPL) due to the limited size and heat sinking capability of the voice coils required for drivers of this size. This performance translated directly into a fatiguing sonic quality due to distortion and limited dynamics due to power compression.

Conventional smaller midrange drivers, loaded in the enclosure style used in existing line array designs, exhibited severe cancellations (up to -18dB) within the drivers intended operating range.

TRIAL & ERROR IN R&D

McCauley’s engineering staff evaluated multiple combinations of cone materials, motor structures, and baffle arrangements. This research and testing determined that several severe limitations could not be overcome via conventional use of small drivers in a line array application.

Figure #1 6.5in, no land

As an alternative, McCauley experimented with 10in drivers. Despite initial reservations regarding their vertical summation issues, the 10in drivers exhibited near perfect horizontal dispersion characteristics up to 1400Hz before collapsing. This performance was significantly higher in frequency than all previously used 6in to 8in drivers. With the horizontal dispersion remaining smooth and free of lobes up to 1400Hz (See Polar #2), these drivers yielded a much smoother on and off axis frequency response, and the sound was far more constant across the entire coverage area.

Figure #2 in enclosure

The next test was to see if these drivers could performing correctly in the vertical plane. McCauley Sound found that as long as the spacing between individual drive units was minimalized and kept constant, they could maintain smooth, lobe free summation in the vertical plane up to 1.7kHz and higher. Our research yielded the HX32™ midrange driver which sums more efficiently, when loaded into the MLA5 design geometry, and exhibits only a -2dB variation compared to standard loading. (see Figure #3 vs. Figure #4)

Figure #3 HX32, no load

Specific to the MLA5, the unique HX32 overcomes the usual limitations of standard large-format drivers, by significantly reducing harmonic distortion and increasing responsiveness and is also far more durable and powerful than the common 6-8in “hi-fi” cone. Most importantly, the HX32 does not exhibit negative performance characteristics such as high distortion product and destructive lobing of the smaller, conventionally used midrange drivers.

Figure #4 HX32 loaded MLA5

The HX32 midrange driver features a contoured, concave cone structure, constructed of a proprietary Carbon-Nomex Honeycomb Composite. Composite materials such as Kevlar have become popular in the last several years, however the benefits of most come at some performance costs. Cones made from pure spun or woven Carbon Fiber and Kevlar have excellent sound qualities and are exceptionally durable, but unfortunately they are almost always heavier than a cone made from paper based material.

A cone driver with the necessary torsional and radial stiffness, required for with such high acceleration demands, often weighs more than twice the equivalent paper cones. This mass greatly limits their performance.

THE SANDWICH SOLUTION

McCauley Sound’s solution is unique in that they use a composite “sandwich” layer process. The outer skins of the cone body are made from thin tightly woven Carbon Fiber. A Nomex honey comb structure is “sandwiched” between the two light layers of Carbon Fiber creating an exceptionally strong and light weight material.

Internal structure of the HX32’s Carbon Nomex Honeycomb core.

This material has an ideal Young’s Modulus, is very well damped, and has a mass break point substantially higher than any other single source material, composite or natural. Ten times stronger than paper, half the weight of pure carbon-fiber, and a third the weight of a pure Kevlar cone, the HX32 cone is capable of low coloration with very high sensitivity. HX32 also retains the composites benefits such as low distortion and durability without being subject to the negative effects such as lower sensitivity and loss of sonic detail due to a heavy moving mass.

Test data reveal the HX32 has the internal damping and response that is comparable to state of the art hi-fi cones while being capable of delivering the far higher professional SPLs.

The distortion products of the HX32 and the best measuring 7in are compared in Figure #5. The drivers were measured at a distance of 1 meter and at 110dBSPL. The 7in drivers were measured together, as a pair, in order to make a more accurate comparison, since all existing line array designs which feature small-scale midrange drivers have them loaded in pairs (four total, two in each hemisphere).

Note that the HX32’s distortion is well below 1% until 175Hz is reached, at which point the primary component becomes the 2nd harmonic with the more objectionable 3rd harmonic remaining well below 1.5 until 100Hz. The THD curve is also free from any radical shifts in the distortion product, giving the HX32 a smoother sound.

In comparison, the more widely used 6.5in driver shows rather substantial amounts of distortion at this SPL level — typically 3% or higher. The shape of the distortion product graph also indicates that the smaller driver has varying amounts of THD at different frequencies, and (subjectively) this could lead to inconsistencies in tonality and clarity at these frequencies.

The primary reasons for the high THD figures is the fact that at this SPL the motor structure is almost totally nonlinear and the driver is experiencing extreme power compression. These problems are avoided with the use of a very durable and lightweight material in the cone structure.

Carbon-Nomex Honeycomb Com-posite is so strong, the entire cone surface operates as a kinetically singular piston, which completely eliminates phase cancellations which would result from the irregular movement and “warping” of a weaker cone structure.

All midrange cones break up into destructive resonance modes as the motion of the cone creates anti-uniformities, and the resulting interpolative waves radiate towards their boundary zones.

However, due to the extraordinary stiffness of the HX32’s Carbon-Nomex Honeycomb Composite cone structure, this break-up occurs at 2.3kHz, which is well outside the driver’s usable bandwidth (it is crossed over at 1.2kHz).

The following graphs show that the HX32, despite being a larger driver, exhibits a better Cumulative Spectral Decay than the 7in driver used for comparison. The graph is plotted as time vs. Frequency and level, the farthest line is the driver driven full bandwidth, then the signal is removed and the next line forward is the amount of energy the driver emits at the next time interval (in this case 0.29ms per graph) until we reach 10ms total time. This chart clearly illustrates the driver/cone resonances. The shorter the decay time, the better.

As demonstrated, the highly responsive surface material allows the HX32 to reproduce mid band energy with a high degree of clarity and tonal detail at substantially higher SPLs and with much lower distortion than anything that has ever been achieved with any conventional midrange driver. The MONARC MLA5 benefits from the enhanced performance of the HX32 by exhibiting a measurable boost in intelligibility, especially in vocal and speech reinforcement.

Top: Two typical line array midrange 7" played and measured @ 110 dB. Bottom: OneHX32 midrange 10" played and measured @110 dB.

INTERCELL COUPLING & DISPERSION CHARACTERISTICS Most conventional line-array designs tend to rely on extensive waveguides and intricate phase correction devices in order to achieve their desired dispersion and mid /high coupling, at the expense of introducing a significant amount of distortion and an overall harshness to the sound. High frequency (HF) waveforms are very fragile, so those same boundary edges that are supposed to “guide ” the HF energy, are also causing the waves to diffract, altering arrival times, and “smearing” the sound. Additionally, the design geometry and rigging schemes of most early line array systems will create a large gap between the forward baffles of adjacent enclosures when rigged to achieve near/down fill coverage. This inconsistency produces audible “holes” in the near field coverage, and the near field is where it is most noticeable to audience members. Designs of this nature also exhibit two additional problematic behaviors; the first is the “bounce”, or diffraction of the HF wave fronts, due to the sudden introduction of a flat boundary that extends to the front of the waveguide as the wave fronts emerge from the wave, blocking the natural vertical dispersion pattern.

This causes a permanent source of comb filtering, and the resulting reflections cause multiple sound sources to be heard, smearing the time signature of transient sounds.

Secondly, designs that pivot at the rear of the enclosure are subject to the diffraction effects of the top and bottom walls, and even worse, as the splay angle is increased, the summation of the individual wavefronts is disturbed as the distance between them is broadened.

These diffractions translate into a measurable loss of intelligibility and obvious irregularities in the resulting dispersion patterns. McCauley Sound designed the MLA5’s mid/high compliment, the ICS Aperture, to eliminate such unnecessary diffractions and resulting distortions. The ICS Aperture’s function is to allow the HF energy from HF waveguides to more efficiently couple with the mid-band energy.

FIGURE #6…CSD of a high quality 6.5 midrange driver. Notice the multiple ridges in the decay axis.

This also reduces the amount of enclosure induced diffraction, and allows the wave fronts to combine into a single seamless entity. Easily recognizable as the “V” shaped section in the center of the cell, the ICS Aperture achieves relatively distortion free mid/high coupling for two reasons. First, MLA5 cells always operate at a fixed frontal spacing, regardless of cell-to-cell splay angles. For this reason, the McCauley Sound the ICS Aperture design is a recessed “trench”, which extends vertically from the top to the bottom of each cell.

FIGURE #7…the CSD of a McCauley HX32 midrangedriver. Notice how the decay is smoother and significantly faster than the driver in Figure #6.

When flown, this creates an uninterrupted vertical HF energy source that traverses the entire height of the array. Since the multiple diffraction edges of an extended waveguide are not present to cause distortion, and because the wavefront is not interrupted by large gaps between enclosures, the HF energy now leaves the array undisrupted, as a continuous line source. The ICS Aperture and POWERLINK™ rigging work in conjunction; the greater the inter-cell wrap is, the more efficient and higher in frequency the summation effect becomes at close distances.

This way, audience members closest to the speakers always receive the best sound possible, not the inconsistent sound of multiple disrupted sources. This is key to the MLA5’s measurably high clarity and intelligibility.

MIDRANGE MANAGEMENT

The other key to achieving distortion-free propagation lies in the placement and design of the midrange elements. In early line array designs, where many small drivers would be clustered in close proximity, the uneven surface topography of the midrange elements would agitate the passing HF waveforms, causing distortions.

Within the ICS Aperture the quantity and intensity of these destructive perturbations are greatly reduced, because the cone structure of the HX32 midrange drivers have been contoured to be physically invisible to the passing HF energy. Again, unnecessary HF diffractions have been eliminated, boosting the clarity of the performance.

When two HX32 midrange drivers are symmetrically arranged within the ICS Aperture, they form both a solid and a kinetic boundary plane. This plane acts as a zero-interfering waveguide for the exiting HF energy, while also establishing the alignment intercept point for coupling with the midband energy.

Without the interference of a physical waveguide, and no irregular protrusions to disturb the passing waveforms, the ICS Aperture becomes an ideal environment for guiding and coupling the mid and HF energies into a vertically continuous, single-source, wide-band wavefront.

In addition, by nature, the MLA5’s ICS Aperture is capable of creating a nearly perfect 90° horizontal dispersion pattern in the direct able bands. Where many large format arrays exhibit significant “drop-off” or “soft-shoulders”, as the listening position moves towards outer edges of their horizontal coverage, a MONARC array’s mid / high dispersion is both consistent, and nearly completely contained within a well defined 90° cone of coverage.

With the MONARC arrays’ ability to create a usable wavefront, measurably consistent across the entire usable bandwidth out to 90° of the horizontal plane, sound designers can rely on a high degree of predictability when planning coverage zones.

INCREASING SPL HEADROOM

A significant weakness seen among early line-array designs was less-than-ideal maximum SPL levels. While these early designs advanced the state of the art by extending the uniformity of coverage over distance, they did so at the expense of overall sound pressure level.

Their driver compliments were not capable of handling the higher power needed to push the array’s combined output into the upper echelons of performance.

McCauley Sound took several steps when engineering MONARC line-array technology in order to overcome this SPL barrier. First, the MLA5’s unique design geometry allows use of a larger, more powerful, and better matched compliment of transducers. The MLA5 employs a 15in-10in-2in-10in-15in symmetrical compliment.

Both LF 15ins are volumetrically loaded to create an acoustical impedance match with the atmosphere and to reduce the individual cell’s Y-axis dimension to under 14in. This volumetric loading of the LF section increases the overall efficiency of the cell by focusing and reshaping the LF energy in alignment with the midband dispersion.

Twin HX32 10in drivers flank either side of the ICS Aperture and represent the midband energy. Finally, a proprietary Unified Titanium Diaphragm high performance compression driver reproduces the remaining HF energy. These components will naturally cross-over more far more smoothly due to the graduated relative sizes.

The construction of the drivers contributes significantly to the array’s SPL capability. Both the low frequency (LF) section’s transducers and the HX32’s feature extremely heat tolerant Inwound™ 4in voice coils. To illustrate the advantage of this, one must note that most conventional drivers have their windings on the outside of the voice coil.

When these drivers get hot from normal operation, this winding expands, and will eventually separate from the coil, causing the driver to short out. McCauley Sound’s InWound technology places the windings inside of the coil.

The coil itself is made from edge wound copper clad aluminum ribbon, and then bonded to the Nomax/Kapton former with special heat-setting adhesives. Not only is this combination both thermally and geometrically stable, but the adhesives actually strengthen under intense heat.

Figure #8: In the "home" position, both the rigging pin have not been moved. Notice how the rear of each adjoining cells have collapsed together and now touch. This facilitates interconnecting the cells, as seen in Figure #9.

COOL BUSINESS Predictably, when the driver gets hot, the winding expands uniformly against the inside of the coil... reinforcing the voice coil, rather than separating from it. This translates into a higher, and more importantly, accurate rather than theoretical power rating. Both the LF and MF sections benefit from the use of multiple spiders in the suspension system. This design resists fatigue which gradually degrades the performance of a transducer with a single spider suspensions. Multiple spiders also help prevent damaging over-excursion of the voice coil on LF peaks, eliminating performance degrading rattling and flapping noise.

Figure #9: Both the rigging pin and the rigging arm have been freed. The arm is swung upward so as to rest in the above cell's interlink channel, then the pin is re-inserted, interconnecting and securing the two cells. This process is duplicated on the opposite side.

These unique features permit the LF/MF compliment of the MONARC MLA5 to handle above average amounts of power. As such, the system can be simply driven harder without risking failure. In addition, the MLA5 is designed with a volumetrically-loaded LF section. The overall cell height of the MLA5 is just over 13in, giving the MLA5 an unusually low vertical profile. Additionally, the design the ICS Aperture guarantees that there is no “dead” space between adjacent cells. Functionally, a MONARC array brings more “firepower” to bear in the same amount of vertical space when compared to the typical rectangular or rear hinging line array designs. In a dead hang, measured at 300ft(91.4m), a 10-cell, 170in(432cm) tall “conventional line” array is needed to achieve 110dB under real-world conditions.

Figure #10: Once all connections have been made, the array is lifted into the air. As each cell is lifted by chain hoist, the rear of each cell slides apart until the rigging arm seats against the rigging pin, thereby holding the splay angle in accordance to the chosen pinning receptacle.

Alternatively, in the same environment, an identical level of sound pressure can be obtained from only an eight-cell, 112in(284cm) tall McCauley MONARC™ array. That’s a 3:2 ratio when comparing array heights, and a 5:4 ratios when comparing the number of enclosures. When factoring in the increase in distortion product that a conventional line array produces when operating at that level, compared to the nearly distortion free wave front that the MONARC array will produce, the difference between the two approaches is even more substantial. RIGGING & TRANSPORT MLA5’s are engineered to be exclusively operated in vertical arrays, and in almost every situation will need to be flown to meet the requirements of the event.

Therefore, all necessary rigging hardware is built into and is integrated within the MONARC MLA5 cells. Also, since the array will need to cover both near and far field audiences, each cell must be constructed to support variety of curvatures.

The MONARC’s POWERLINK™ Integrated Rigging System was designed with simplicity and efficiency in mind. This suspension technology allows a full 10° of freedom per cell, requires no tools, has no extra pieces to lose, uses no straps, no tethers, is not exposed to damage and requires no hand lifting to fly.

This approach to rigging technology translates into quicker fly-times, a wider range of possible splay angles, more accurate down fill, side fill and upper balcony coverage, and easier packing and trucking. With the POWERLINK system, the rigging process has been simplified so much that, once on deck, two crew people can easily have the entire rig interlinked and flown in under ten minutes.

The POWERLINK rigging system is essentially comprised of two different mechanisms... the front-side tongues and the back-side “spine”. The front-side of the POWERLINK system consists of two spring loaded, high-tensile steel tongues, which are conveniently stored within the MONARC’s POWERLINK system itself.

After both of the front quick release pins are removed, the tongues spring out from their protective housing, and can be quickly and easily inserted and secured into the next MONARC cell using the same quick-release rigging pins. Once each cell has been connected to it’s neighbor, all of the cells in the array are now locked together at a fixed front-side spacing of just under 1/4in.

What is important to note, is that even though the MONARC cells are locked together at this fixed spacing, the connection between the cells is hinged, to permit vertical pivoting in either direction. This constant spacing of the forward baffles is vital for maintaining the MONARC line array’s acoustical coupling characteristics.

Once all the front-sides of every cell in the array have been interconnected, and the top MLA5 cell has been secured to the bumper, the hoist operator lifts the array approximately 5-6 feet off the deck, bringing as many as ten MLA5 cells up in the air, but still within easy reach of the crew. Hoisting the system off the deck causes the rear sides of the raised MONARC cells to collapse together.

As with the front-side, the crew now moves to the backside of the raised cells, and removes the quick-release rigging pins from the backside interlink channel, which frees a swinging hinged arm from its’ home position within the system’s spine. The arm is swung upward, and placed into the above cell’s interlink channel.

Each interlink channel has a series of seven pinning receptacles, each receptacle representing a possible splay angle ranging from 0° to 10°. Quick release pins are simply inserted into the receptacle that represents the splay angle desired. This secures the swinging arm and connects the spine and the two adjoining cells.

Finally, castor boards (if used) are removed and set aside. The array is lifted again, until the remaining cells collapse, and the process is repeated. Once all cells are interconnected and secured, the array is hoisted. When lifted into the air, the cells expand until they each reach their specified splay angle.

FAST & FLEXIBLE

POWERLINK’s “spine” can be re-configured to create a completely rigid, non-collapsible array, which is useful when building groundstacks or flying radically tilted array configurations, as would be used for permanent installations or non-concert events.

Regardless of chosen splay angles or final curvature, a MONARC array is designed to “free” hang vertically from the bumper, does not require any rear hoisting or bracing, even when configured for extreme down fill and up fill balcony coverage. The POWERLINK rigging system is so flexible that up to 10° of positive (upfiring) top cell splay can be achieved, without any additional hardware, and without the need to radically tilt the bumper.

As the array is being lifted, the castor boards snap off to be stored. Alternatively, the system can be pre-linked, and rolled into the venue in groups of four.

With POWERLINK, sound designers can create practically any array curvature, ranging from a straight hang to a completely collapsed half-moon while maintaining a constant forward baffle spacing of less than 1/4in between systems. Keeping the forward-radiating baffles locked at a fixed spacing of 1/4in is key to maintaining the wavefront summation characteristics and other acoustic benefits that MONARC line array technology provides. This tight, radical curvature can eliminate the need for separate down fill systems, and can even eliminate front fills when the array is properly configured.

Flying from a standard bumper system, the MONARC system can even achieve down fill angles as extreme as nearly parallel to the deck, without the need to be “raked” back behind the stage by straps or tether.

FOH benefits include boosted gain-before-feedback ratios from the mains, with less stage interference, and a high quality, near-field listening experience.

Each MONARC MLA5 cell comes equipped with a rugged, snap-on castor board, which makes moving the MLA5 quick and efficient. The MLA5’s castor system is designed to break away from the MLA5 cell without any extra parts or tools to lose.

Once off-duty, the castors will interlock when stacked, to aid storage. An optional FastPack™ cart allows up to four MLA5 cells to be stacked and transported together, with their POWERLINK rigging pre-configured for the next venue. This option streamlines truck-packing and reduces the labor call.

July/August 2001 Live Sound International