Owner's Manual

The Effects of Bi-Wiring and Bi-Amping

Fundamentally a loudspeaker crossover varies the impedance seen by the speaker and by the power

ampliﬁer. When a full range audio signal is applied to the terminals of a full range speaker system, the bass

driver(s) will only receive low frequency signals, the mid driver receives the mid band frequency signals and

the tweeter only gets sent high frequency signals.

This means that if separate speaker cables are connected to the low and high frequency terminals, not only

have the drive units had the frequency’s directed and divided for them, but if using a bi-wire setup the two

separate speaker cables will now also carry different signals due to the impedance. So the bass cables

carry mostly the low frequencies, and the tweeter cable mostly the highs.

The effects of bi-wiring are subtle and depending on the cable construction and design it could be better to

go for one better engineered cable than two for bi-wiring. Monitor Audio recommends experimenting with

both conﬁgurations to ﬁnd out which one works best in your system.

Bi-amping adds an additional ampliﬁer to the system so that the one ampliﬁer drives the low frequencies

and the other ampliﬁer drives the high frequencies. Bi-amping can therefore present a ‘cleaner’ signal at

both the low frequency and high frequency speaker terminals, and because the high and low frequencies

have already been separated, each has a minimal effect on the other - in essence the bass has less

effect on the delicate treble. In order to best take advantage of bi-amping the ampliﬁers should be as

independent from each other as possible. For instance, if using two stereo ampliﬁers you should use one

stereo ampliﬁer for the bass and the other for the treble, minimising the impact of the bass on the treble.

Port Bungs

WARNING: Care must be taken not to insert the port bungs too far into the port, as this

may result in the foam bung being lost inside the cabinet.

If the loudspeaker is to be installed in a small room, typically 9 sqM (80 sqFT), or a room known to

reproduce an accentuated bass response, it may be desirable to ﬁt port bungs. However, experimentation

is recommended with positioning of the loudspeaker in the room prior to ﬁtting. To optimise performance

from the loudspeaker it is important to ensure the loudspeaker is not positioned too close to a wall or near

the corners of a room.

If the positioning of the loudspeaker is predetermined by room aesthetics or layout, you ﬁnd you have

accentuated bass or in the case speakers are to be sited in close proximity (less than the minimum

suggested distances shown in the 2 Channel Positioning section) to a rear wall (such as on a bookshelf,

positioned in a cabinet or on a stand close to a wall), we recommend ﬁtting port bungs to the ports. This

will reduce the bass ‘boom’ sometimes termed as overhang, and assist the loudspeakers to reproduce

their best performance under these environmental conditions. ‘Boom’ is generally caused when bass

energy from the loudspeaker ‘excites’ room modes and causes an accentuation at a particular frequency,

or number of frequencies.

When ﬁtting port bungs the overall bass extension will not be reduced, however bass energy/ output

around the port tuning frequency will be reduced. This has the effect of reducing bass ‘boom’ while

increasing bass clarity and apparent agility.

In all circumstances experimentation is highly recommended.

Bronze Series