Monoprice 14887 User manual

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SAFETY WARNINGS AND GUIDELINES
Turn off and unplug all equipment prior to making electrical connections, including
speaker wire connections.
Reduce the volume level prior to making any change to the audio input source, e.g.,
changing radio stations or changing CDs.
When using this speaker as part of a constant voltage speaker system, ensure that
the amplifier power is at least 20% higher than the total power settings of the
connected speakers.
Most speaker damage is caused by clipping, which is heard as distortion. If you hear
distortion, reduce the volume level until the audio is no longer distorted.
Take care to ensure that the speaker wire connections are properly polarized.
Inverted polarization can result in unnatural or attenuated sound, especially in the
bass frequencies.
Do not use chemical cleaners or solvents to clean this speaker. Use only a soft, dry
cloth. Moisten the cloth with warm water for particularly stubborn deposits.
INTRODUCTION
Thank you for purchasing this Coaxial In-Ceiling Speaker!
This 2-way speaker features a built-in step-down transformer, allowing it to be used as part
of a 70V or 100V constant voltage speaker array with four (100V) or five (70V) taps. It can
also be configured as a conventional 8-ohm speaker for use in a standard home theater
audio system. The speaker has a preinstalled back can, which helps deliver superior audio
quality.

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FEATURES
8 ohms nominal impedance
Compatible with 70V and 100V constant voltage speaker systems
Built-in step-down transformer with 4 (100V) or 5 (70V) taps
Preinstalled back can for superior audio quality
PACKAGE CONTENTS
Please take an inventory of the package contents to ensure you have all the items listed
below.
1x Coaxial in-ceiling speaker
1x Grille removal tool
1x Cutout template
1x User's manual
CONSTANT VOLTAGE VS 8-OHM SPEAKER SYSTEMS
A constant voltage speaker system differs from a traditional 8-ohm speaker system in that
it uses a step-up transformer at the audio source to raise the voltage and lower the current
on the transmission line. At the speaker end, a step-down transformer converts the signal
back to a normal speaker level voltage. This reduces power loss during transmission, which
allows for the use of longer speaker wire runs using smaller gauge wire.
Additionally, a constant voltage speaker system allows for the use of multiple speakers on
each channel, without the need for complicated impedance calculations and
configurations. In a constant voltage system, all speakers on a given channel are connected
in parallel and the complicated impedance calculations are replaced by simple wattage
calculations.
For example, if you want to connect two speakers per channel in a traditional 8-ohm
speaker system, you must either connect them in series, which results in an overall 16-ohm
impedance, or in parallel, which results in an overall 4-ohm impedance. In the first case, the

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16-ohms impedance effectively halves the output power of your amplifier, resulting in
lower overall volume levels. In the latter case, the 4-ohms impedance means that your
amplifier will have to work harder and must be rated as stable at 4 ohms. Adding a third
speaker to the mix would complicate it further, producing either a 24-ohm or 2.67-ohm
overall impedance. Note that very few amplifiers are stable under 2-ohm loads, so that is
usually not an option.
On the other hand, with a constant voltage system, you consider first the RMS output
wattage of the amplifier. This should be reduced by 20% to compensate for insertion loss.
For example, if using a 100-watt amplifier, the total load from speakers should not exceed
80 watts.
Each individual speaker on a given channel is set to a value such that the total does not
exceed the rated power, less 20%. You do not need to worry about making the total as
close as possible to the limit; just ensure that the total does not exceed the limit.
If all speakers are set to the same wattage value, they will all have the same volume level.
If one speaker is set to a higher wattage value, it will be louder than the others, while a
speaker set to a smaller value will be quieter than the others. This allows you to
compensate for the environment in which the speaker is placed. For example, a speaker
placed outside would need to be louder than a speaker placed in a small room.

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SPEAKER WIRING
If using this speaker as a conventional 8-ohm speaker, most
installations will consist of only a single speaker per channel.
Wiring a speaker this way is straightforward, with a single
two-conductor speaker wire running from the amplifier to
the speaker's inputs.
However, when used as part of a constant voltage speaker
system, most installations will consist of multiple speakers
per channel. In this case, all speakers are connected in
parallel, as shown in the diagram to the right.
To wire speakers in parallel, connect the first speaker to the
amplifier as normal. Connect the positive terminal on the first
speaker to the positive terminal of the second speaker, and
the negative terminal on the first speaker to the negative terminal on the second. Repeat
for each additional speaker in the array.
INSTALLATION
Perform the following steps to install and setup this speaker for operation.
1. Power off and unplug all equipment that will be connected to this speaker.
2. If you will be using this speaker as a standard 8-ohm speaker, set the tap knob to
the 8Ω position.
3. If you will be using this speaker as part of a 70V or 100V constant voltage speaker
array, set the tap knob to one of the 70V or 100V wattage positions. The total
wattage rating of all speakers in the array must not exceed 80% of the amplifier's
RMS power rating.
Example: If using two model 14887 speakers and two model 14888 speakers in a
single 70V speaker array using the model 14886 120-watt amplifier, set the taps on
the two 14887 speakers to 25 watts and the taps on the two 14888 speakers to 20
watts. This produces a total load of 90 watts, which is less than the 96 watt
maximum that represents 80% of the 120-watt amplifier's rated power output.

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Note: Use only one of these options. Do not mix speakers set for low impedance
operation with speakers set for constant voltage operation.
4. Determine the mounting location of the speaker. Use a stud finder or probe to
ensure that the desired location in unobstructed.
5. Using the included installation mask and a pencil, mark the cutout hole at the
desired location.
6. Use a drywall saw or other tool appropriate for the ceiling material to cut the
mounting hole.
7. Run speaker wire from the amplifier to the speaker installation location.
Important Safety Warning! If installing this speaker in the ceiling, you must use in-
wall rated speaker wire for residential installations or plenum rated speaker wire for
commercial installations.
8. Connect the speaker wire to the speaker, taking care to ensure that polarity is
properly maintained.
9. Use the included grille removal tool to remove the speaker grille.
10. Use a screwdriver to turn the mounting tabs inward.
11. Insert the speaker into the hole, then use the screwdriver to turn the mounting tabs
outward and tighten them until the speaker is securely seated against the ceiling.
12. Replace the speaker grille.
TROUBLESHOOTING
Q1: The sound from one of the speakers is muddy, with attenuated bass response.
A1: Double check the polarity of the speaker wire connections.

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Q2: The sound from one of the speakers is louder or quieter than the other speakers in a
constant voltage system.
A2: Check the wattage settings of the affected speaker. If it is higher than that of the
other speakers, it will be louder. Similarly, if it is set to a lower value, it will be quieter
than the other speakers. To get the same volume level, set the switch to the same
wattage setting as is used on the other speakers.
Q3: The sound from all the speakers is scratchy, harsh, or fuzzy sounding.
A3: You are hearing audible distortion, which can cause damage to both the speakers and
the amplifier. Reduce the volume level until distortion can no longer be heard in any
part of the audio signal.
SPECIFICATIONS
Model
14887
14888
Woofer Size
6.5-inches
4-inches
Input
8 ohms, 70V, or 100V
8 ohms, 70V, or 100V
70V Power Taps
3, 6, 12.5, 25, and 50 watts
1.25, 2.5, 5, 10, or 20 watts
100V Power Taps
6, 12.5, 25, and 50 watts
2.5, 5, 10, or 20 watts
Transformer Impedance
1.7k, 700, 400, 200, or 100 ohms
4k, 2k, 1k, 500, or 240 ohms
Frequency Response
90Hz ~ 20kHz
110Hz ~ 16kHz
SPL (1 watt@1 meter)
90dB
88dB
Cutout Diameter
ø9.8" (ø250mm)
ø7.1" (ø180mm)
Dimensions
ø11.0" x 7.5" (ø280 x 190 mm)
ø8.4" x 5.3" (ø213 x 135 mm)
Weight
6.2 lbs. (2.8kg)
4.2 lbs. (1.9kg)

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REGULATORY COMPLIANCE
Notice for FCC
This device complies with Part 15 of the FCC rules. Operation is subject to the following two
conditions: (1) this device may not cause harmful interference, and (2) this device must accept any
interference received, including interference that may cause undesired operation.
Modifying the equipment without authorization may result in the equipment no longer complying
with FCC requirements for Class B digital devices. In that event, your right to use the equipment
may be limited by FCC regulations, and you may be required to correct any interference to radio or
television communications at your own expense.
This equipment has been tested and found to comply with the limits for a Class B digital device,
pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection
against harmful interference in a residential installation. This equipment generates, uses and can
radiate radio frequency energy and, if not installed and used in accordance with the instructions,
may cause harmful interference to radio communications. However, there is no guarantee that
interference will not occur in a particular installation. If this equipment does cause harmful
interference to radio or television reception, which can be determined by turning the equipment
off and on, the user is encouraged to try to correct the interference by one or more of the
following measures:
Reorient or relocate the receiving antenna.
Increase the separation between the equipment and receiver.
Connect the equipment into an outlet on a circuit different from that to which the receiver
is connected.
Consult the dealer or an experienced radio/TV technician for help.
Notice for Industry Canada
This Class B digital apparatus complies with Canadian ICES-003.
Cet appareil numérique de la classe B est conforme à la norme NMB-003 du Canada.