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4. How to set up your home theater system
User manual
A home theater system includes the main speaker systems (covered by this users guide) and includes at least three additional speakers : a center channel speaker and two surround sound speakers. We encourage the use of a subwoofer to reproduce the extreme low frequency signals required by the special effects found in movie soundtracks. The setup requires the same general criteria outlined before, in addition to the following considerations :
•The center channel must be placed near the screen to obtain the proper placement of the dialogue; avoid placing it too high or low or you could lose clarity and resolution.
•The surround speakers should be placed according to their function, that is to the sides for
•The subwoofer is less critical when it comes to placement; nevertheless, it is good practice to place it in front of the listening position and away from corners to avoid undue excitation of low frequency room resonant modes.
•Home theater processors and amplifiers generally offer built in test signals to help set up and adjust the balance and levels of the different channels. For more information, please check the JMlab users manual provided with your home theater speaker systems, as well as the users guide furnished with your processor, amplifier or receiver.
About amplifiers
•Recommended amplifier power
Although there is no strict rule, theoretically the ideal choice would be an amplifier which has the same RMS power as the maximum continuous power of the loudspeaker (example: speaker rated at 100W max. = 80 to 100W amplifier).
Caution : Avoid using an
However, if the owner has an amp. of this type, there is no danger in using it at normal listening levels. In this case, care should simply be taken not to exaggerate the volume, treble or bass levels for extended periods of time (for example at social gatherings, parties etc. when the sound is muffled by the mass of people dancing, etc .).
•Matching the power to the listening source
Once again, contrary to popular belief, it is not possible to judge the power of an amplifier by the position of the volume control button.
-With modern digital sources (CD, DVD, …) which have a high output level (2V), the amplifier reaches maximum power as soon as the volume control is turned to the “two o’clock” or even “one o’clock” position. In this case, there is rarely any power reserve in the amplifier, and it is probably already about to start peaking.
-With conventional analogical sources (phono, tuner, tape) which have lower outup levels, the volume control can be turned up beyond this point without maximum power being reached.
Glossary
Woofer : Bass loudspeaker, the one with the largest diameter.
Tweeter : Treble loudspeaker, the one with the smallest diameter
Midrange : Midrange loudspeaker in the case of a three way speaker, the one with an intermediate diameter.
Frequency : Rating characterizing the tone of the bass range sound while going through the midrange, up to the treble, shown in hertz : Hz.
Amplitude : Characterizes the sound level; shown in decibels (dB). A speaker must be linear in order to reproduce the bass, midrange and treble frequencies at the same level.
Sensitivy : Shows the electric power to be supplied by the amplifier in order to obtain a certain sound level at 1m distance; shown in dB/2.8V/m (or efficiency in dB/W/m).
Power of speaker : This is the maximum level of the electric signal from the amplifier that a speaker can sustain in continuous operation,
before being damaged. Expressed in Watts: W. This rating does not bear upon the sound level that the speaker can supply, which depends in fact on sensitivity.
Impedance : This is the load represented by the acoustic speaker for the amplifier, expressed in ohms : Ω. This rating varies with frequency, the minimum reading is the most important.
Vent : Tuning tube of the acoustic speaker in the case of a
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