Filter
Top Products
Page 14
• The negative output terminal of the right channel connects to the negative input post of the fi rst
speaker and to the negative post of the second speaker.and
The total impedance of equal speakers in parallel is found by dividing the impedance of one speaker
by the number of speakers. For example, two eight ohm speakers in parallel is a four ohm load (eight
ohms divided by two), four eight ohm speakers in parallel is a two ohm load (eight ohms divided by
four). Two ohm single channel loads are NOT RECOMMENDED for the XPA-1!
Running the XPA-1 below recommended impedance level can cause excessive heat and will
eventually drive the amplifier into protection
(blinking red LED’s on the front of the unit).
Parallel connections are harder on the amplifier than series connections, as the total impedance is
lower compared to driving a single speaker, and the amplifier must produce more current to drive
them.
Ideally, the total average impedance should be no less than 4 ohms per channel. You must make sure
that the lower impedance does not cause the amplifier to overheat, shut down, blow the line fuse, or
trip your circuit breaker. If this happens, you should reduce the number of speakers wired in parallel,
rewire them in series, or use more than one power amplifier.
Technical Note about Multiple Speaker Connections
Although there are two possible connection types discussed in this manual, it is imperative that with
either connection type that you use loudspeakers of the same type and nominal impedance for these
connections. In doing so, you have the most predictable outcome for your installation. When speakers
of different nominal impedances and/or different bandwidths are used, there are many other acoustic
problems that come into play in addition to complex impedance at the amplifier’s speaker output
terminals. If you must use multiple speakers on any individual amplifier channel, please use speakers
as close to identical as possible.