A loudspeaker is provided for receiving an incoming electrical signal and
transmitting an acoustical signal. The loudspeaker may include a power
amplifier that has an input and an output, where the input receives the
incoming electrical signal. The loudspeaker may also include two or more
passive filters, such as low-pass, band-pass, and/or high-pass filters,
which are coupled to the output of the power amplifier. The passive
filters may also be coupled to one or more speaker drivers. The
arrangement of passive filters and speaker drivers may have a single
input that has a combined input impedance. The output of the amplifier
may have an output impedance. The output impedance may be between about
25% and about 400% of the combined input impedance. The power amplifier
may include a current-feedback amplifier that is configured to maintain
the desired output impedance.