The HPS series is designed for use with a receiver or amplifier
having a maximum power output of 250 watts per channel at
8 ohms. Damage caused by the use of a higher-power receiv-
er or amplifier will void the warranty. Consult your Niles deal-
er, or receiver/amplifier manufacturer, if you are uncertain
about the power rating of your receiver or amplifier.
Amplifier Impedance Load
As more pairs of speakers are parallel connected to a receiver
or amplifier, the overall system impedance becomes lower.
For example, if two pairs of 8-ohm speakers are connected in
parallel, the impedance will be 4 ohms; two pairs of
4-ohm speakers in parallel become 2 ohms, and so on.
Most receivers or amplifiers are not rated for use below a
4 ohm load. Most manufacturers do not recommend con-
necting more than two pairs of speakers without using some
form of impedance correction.
The HPS series includes impedance correction circuitry which
protects your receiver or amplifier from low impedance
loads. The circuitry assures that your receiver or amplifier will
see a safe operating load, even when all four speaker pairs
are playing at the same time.
The actual impedance load the speaker selector presents to
your receiver or amplifier will vary, depending on how many
speaker pairs are playing, and the impedance rating of each
speaker. If you have four pairs of 8-ohm speakers playing, the
HPS-4/HPS-6 series will present a 4.5 ohm impedance load to
3. Locate the on/off buttons on the HPS-4/HPS-6 which cor-
respond to the speaker pairs you wish to play. Set them to
the ON position (Engaged).
4. Turn on the amplifier or receiver and select a source, such
as the tuner or CD player.
5. Slowly turn up the amplifier or receiver volume and set it
to a comfortable (not maximum) listening level. Be careful
not to overdrive or “clip” your amplifier. If the sound
becomes muddy or distorted, you have reached the limit
of your amplifier’s volume capability and should quickly
reduce the volume to avoid damaging your speakers.
You will need
to activate the
whenever the overall
might fall below
When playing the following speakers:
1 or 2 pairs of 8-ohm speakers
3 or more pairs of 8-ohm speakers
1 pair of 4-ohm speakers
2 or more pairs of 4-ohm speakers
Any combination of 4 and 8 ohm speakers
The Protection button should be:
Set the PROTECTION button to the correct position using the chart shown above.