Placement

WARNING: Installation should only be done by

an experienced technician. Improper instal-

lation may result in damage to the equip- ment, injury or death. Make sure that the loudspeaker is installed in a stable and secure way in order to avoid any conditions that may be dangerous for persons or structures.

The HD1521 speaker is designed to sit on the floor or stage. It may also be pole-mounted via the built-in socket on the bottom of the cabinet. Be sure the pole is capable of supporting the weight of the HD1521. The HD1521 may also be flown horizontally or vertically via its 12 integrated fly points.

Check to make sure that the support surface (e.g., floor, etc.) has the necessary mechanical characteristics to support the weight of the loudspeaker(s).

When pole-mounting loudspeakers, be sure that they are stabilized and secured from falling over or being accidentally pushed over. Failure to follow these precautions may result in damage to the equipment, personal injury, or death.

You can create a horizontal array by placing the cabinets side-by-side. However, you should have a good understanding of the relationship between the splay angle (the angle between the facing sides of the cabinets), the on-axis power, and frequency cancellation effects between cabinets.

When two cabinets are positioned vertically side- by-side, the actual splay angle is 20º (determined by a 10º angle on each cabinet side). As the splay angle increases toward the angle of horizontal coverage (80º for the HD1521), the on-axis power decreases, but the frequency response becomes smoother as the comb-filtering effects (caused by the interaction in the area of double-coverage) decrease.

As with any powered components, protect them from moisture. Avoid installing the loudspeaker in places exposed to harsh weather conditions. If you are setting them up outdoors, make sure they are under cover if you expect rain.

Room Acoustics

The HD1521 loudspeakers are designed to sound neu- tral; that is, to reproduce the input signal as accurately as possible.

Room acoustics play a crucial role in the overall performance of a sound system. Here are some additional placement tips to help overcome some typical room problems that might arise:

• Avoid placing loudspeakers in the corners of

Owner’s

a room. Doing so increases the low frequency

 

 

output and can cause the sound to be muddy

 

 

and indistinct.

 

 

• Avoid placing loudspeakers against a wall. This,

 

 

too, increases the low frequency output, though

 

 

not as much as corner placement. However, this

Manual

is a good way to reinforce the low frequencies,

 

 

if so desired.

 

 

• Avoid placing the speakers directly on a hol-

 

 

low stage floor. A hollow stage can resonate at

 

 

certain frequencies, causing peaks and dips in

 

 

the frequency response of the room. It is better

 

 

to place the loudspeakers on a sturdy table

 

 

or stand designed to handle the weight of the

 

 

HD1521.

 

 

• Position the loudspeakers so the high-frequency

 

 

drivers are 2 to 4 feet above ear level for the au-

 

 

dience (make allowances for a standing/danc-

 

 

ing in the aisles audience). High frequencies

 

 

are highly directional and tend to be absorbed

 

 

much easier than lower frequencies. By provid-

 

 

ing direct line-of-sight from the loudspeakers to

 

 

the audience, you increase the overall bright-

 

 

ness and intelligibility of the sound system.

 

 

• Highly reverberant rooms, like many gymna-

 

 

siums and auditoriums, are a nightmare for

 

 

sound system intelligibility. Multiple reflections

 

 

off the hard walls, ceiling, and floor play havoc

 

 

with the sound. Depending on the situation,

 

 

you may be able to take some steps to minimize

 

 

the reflections, such as putting carpeting on

 

 

the floors, closing draperies to cover large glass

 

 

windows, or hanging tapestries or other materi-

 

 

als on the walls to absorb some of the sound.

 

 

However, in most cases, these remedies are not

 

 

possible or practical. So what do you do? Mak-

 

 

ing the sound system louder generally doesn’t

 

 

work because the reflections become louder,

 

 

too. The best approach is to provide as much di-

 

 

rect sound coverage to the audience as possi-

 

 

ble. The farther away you are from the speaker,

 

 

the more prominent will be the reflected sound.

 

 

Use more speakers strategically placed so they

 

 

are closer to the back of the audience. If the

 

 

distance between the front and back speakers

 

 

is more than about 100 feet, you should use a

 

 

delay processor to time-align the sound. (Since

 

 

sound travels about 1 foot per millisecond, it

 

 

takes about 1/10 of a second to travel 100 feet.)

 

 

Keep in mind that the Contour EQ is a great way to

 

 

compensate for some of these issues.

 

 

 

 

 

 

 

 

Owner’s Manual