Radio Shack MPA-50 Скачать руководство пользователя страница 6

6

Speakers

ˆ

Speakers

SPEAKER PHASING

Phasing is the direction the speaker
cone moves with reference to the polari-
ty of the connection wires. Proper phas-
ing is important when you use more than
one speaker in the same room or area.
Out-of-phase speakers can lose up to
one-half of their potential volume, and
can have a significantly decreased bass
effect.

Speakers are in phase if all the speaker
cones move in the same direction when
an equal signal is applied. Phasing is
correct if you observe the correct polari-
ty (+ to + and – to –) when connecting
the speakers.

Most speaker terminals are color-coded
or have a mark that indicates the termi-
nal’s polarity. Usually, terminals with
positive polarity are red or have a plus
symbol (+), and terminals with negative
polarity are black or have a minus sym-
bol (–). If the speaker terminals are un-
marked, follow these steps to determine
their polarity.

1. Remove about 1 inch of insulation

from both ends of a short piece of
wire (available at your local
RadioShack store). Then twist the
exposed wire to secure all its
strands.

2. Connect one end of the wire to one

of the speaker terminals.

3. Touch the positive end of a 1.5-volt

flashlight battery to the speaker ter-

minal that does not have the wire
attached to it.

4. Touch the negative end of the bat-

tery with the lose end of the wire
attached to the other speaker termi-
nal. Note the direction of the cone
movement — inward or outward.

5. If the speaker cone moves outward,

the speaker terminal where you
touched the positive end of the bat-
tery is positive. Mark that terminal
with a + and mark the other terminal
with a –.

If the speaker cone moves inward,
the speaker terminal with the wire
attached that touched the negative
end of the battery is positive. Mark
that terminal with a + and mark the
other terminal with a –.

6. Remove the wire.

Repeat Steps 2–6 for each speaker with
unmarked terminals you plan to connect
to the amplifier.

DETERMINING TOTAL 
SPEAKER IMPEDANCE

Caution: A total speaker impedance
that is higher than 16 ohms (

) or lower

than 4 ohms can damage your amplifier
or speakers. Be sure to make the proper
connections.

Before you connect speakers to the am-
plifier, you must determine the total
speaker impedance. In determining the
total speaker impedance, you must first

32-2002.fm  Page 6  Friday, February 11, 2000  11:36 AM

Содержание MPA-50

Страница 1: ...Owner s Manual Please read before using this equipment MPA 50 40 Watt PA Amplifier 32 2002 fm Page 1 Friday February 11 2000 11 36 AM...

Страница 2: ...edance 6 Connecting Speakers 7 One Speaker 8 Two or More Speakers Without Transformers 8 Multiple Speakers with Transformers 10 Controls and Operation 12 Troubleshooting 13 Care 14 Replacing the Fuse...

Страница 3: ...Auxiliary Volume Control lets you adjust the volume of the connected equipment Priority Terminals let you connect an optional switch to cut out all other au dio input sources and give priority to onl...

Страница 4: ...with adequate venti lation Do not place the amplifier on thick carpeting or cushions which can restrict the air flow or near a heat source such as a heat vent or radiator which can cause the amplifie...

Страница 5: ...r turntable to this screw to avoid a low frequency hum You can also use this screw to ground any other system connection PHONO AUX CD Switch Select the input source Even if you connected auxiliary equ...

Страница 6: ...2 Connect one end of the wire to one of the speaker terminals 3 Touch the positive end of a 1 5 volt flashlight battery to the speaker ter minal that does not have the wire attached to it 4 Touch the...

Страница 7: ...ohms If you connect more than two speak ers using only series or only parallel connections the total impedance might exceed the amplifier s maxi mum impedance 16 ohms or fall below its minimum impedan...

Страница 8: ...d system you must determine the total impedance of the speakers before you can make the correct connection The total impedance of all the speakers must match one of the amplifier s output terminals 4...

Страница 9: ...this example Series and Parallel Combined If you must hook up more than two speakers you might have to use a com bination of series and parallel connec tions to get a total impedance that matches one...

Страница 10: ...require many speakers and long runs of connecting wire we recom mend you use a line transformer not supplied Note When running lengths of wire longer than 50 feet use wire that is heavier than 16 gaug...

Страница 11: ...n necting a 2 5 watt speaker to a transformer connect this wire to the 2 5 tap on that transformer s primary side 2 Connect a wire from the amplifier s COM terminal to the COM tap on each trans former...

Страница 12: ...PHONO AUX Source Mixing Control Adjusts the input level of the PHONO or AUX CD sound source for the best volume and balance 150Hz Equalizer Control controls output for instruments in this very low ra...

Страница 13: ...ker wire You should always use 16 gauge or larger wire The longer the run of speaker wire the heavier the gauge should be If you have feedback problems reposi tion your microphones and speakers or adj...

Страница 14: ...RadioShack store for assistance REPLACING THE FUSE The power fuse protects your amplifier from power voltage or current surges when operating it from an AC power source If the POWER indicator does no...

Страница 15: ...z AUX CD 70 Hz 20 kHz PHONO 100 Hz 12 dB 10 kHz 13 dB Equalizer Control Range at Each Band Peak Point 150Hz 12 dB 1kHz 12 dB 6kHz 12 dB Crosstalk from AUX to PHONO 40 dB Nominal Hum and Noise at 8 Ohm...

Страница 16: ...efect during the warranty period take the product and the RadioShack sales receipt as proof of purchase date to any RadioShack store RadioShack will at its option un less otherwise provided by law a c...

Отзывы: