Harman JBL DX-1, Руководство пользователя, Страница: 5 / 14

6
Amplifiers
As stated above, the amplifiers used for the low and high frequency spectra need not be the same model, brand or even type, and need not have
the same input sensitivity. In most installations, particularly with two-way loudspeaker systems equipped with compression drivers, the high fre-
quency transducers will not require as much electrical power to reach the same room loudness as the low frequency sections.
There are many variables involved in the selection of the amplifiers for a particular system, including the particular loudspeaker model, the size of
the listening room, the placement of the loudspeakers in the room, the maximum listening level and type of program material used, and your per-
sonal preferences. Consequently, we recommend that the amplifiers for your installation be selected in consultation with your JBL DX-1 dealer.
Bridged Low Frequency Amplification
Some two-channel power amplifiers may be operated with both channels coupled together so that they operate as a more powerful single-channel
unit. This mode, called bridging, is particularly useful for low frequency amplifiers which may have the desired sonic character but do not have suf-
ficient output power available in each channel.
In bridge mode, both channels are fed with the identical signal, but the signal fed to one of the channels (usually Channel B) has inverted polari-
ty. The loudspeaker wires are connected to the “hot” or “+” (usually red) output terminals of both channels, with the red terminal of the speaker
usually connected to Channel A’s hot terminal, and the black speaker terminal connected to Channel B’s hot terminal. No connection is made to
the “–” (usually black) amplifier terminals. The DX-1 has both standard and inverted polarity low frequency output jacks, simplifying the task of
bridging if this mode is employed.
Caution: Some power amplifiers may not be compatible with bridge mode operation and may be damaged if this configuration is
used. Also, the minimum operating impedance of an amplifier in bridge mode is double the minimum impedance of each channel
alone. For example, a power amplifier with a 4 ohm minimum rating in two-channel mode should not drive a load below 8 ohms
impedance in bridge mode. Consult your dealer or the amplifier manufacturer to confirm the suitability of a particular amplifier before
attempting to bridge its channels together.
Other Electronics
Because bi-amplification improves the ability of the loudspeaker system to accurately reproduce the signal which has been fed into it, the quality
of all associated electronic equipment in the system, and, indeed, of the program source, should be of the highest level. The interconnections
should also be premium grade. An accurate loudspeaker system will faithfully reproduce any flaws in the audio signal presented to it, and percepti-
ble audio problems may originate anywhere in the audio chain.
Safety Considerations
Please note the following safety considerations before proceeding with the installation of your DX-1 Electronic Dividing Network. Exercising proper
precautions in the setup and use of this product will ensure your safety and satisfactory, long-term performance from this product.