Channel power (@1-ohms)
Rated power output by the amplifier per channel when a load (speakers) with a nominal impedance of 1 ohm is connected to it (for more details, see "Maximum impedance"). By rated power, conscientious manufacturers most often mean the so-called RMS (Rated Maximum Sinusoidal) — the highest output power at which the amplifier is guaranteed to work for an hour without damage; it is much less than the maximum value (see below for more details).
In general, the higher the rated power, the higher the sound volume that the amplifier can produce (ceteris paribus, including the characteristics of the connected acoustics). This indicator also determines compatibility with car audio: the speakers connected to each of the channels should ideally have the same rated power (in fact, a deviation of 10-15% is allowed).
Channel power (@2-ohms)
Rated power output by the amplifier per channel when a load (speakers) is connected to it with a nominal impedance of 2 ohms. For details, see "Nom. channel power (at 1 Ohm)”.
Channel power (@4-ohms)
Rated power output by the amplifier per channel when a load (speakers) with a nominal impedance of 4 ohms is connected to it. For details, see "Nom. channel power (at 1 Ohm)”.
Max. power
The highest
output power provided by the amplifier. It is worth noting that this indicator is not standardized, and different manufacturers may mean different values \u200b\u200bfor it — for example, the highest power of short-term, in a fraction of a second, peaks (power surges), the highest power that the amplifier can transfer for several seconds, or even the power at which the device will fail. Therefore, it makes no sense to compare different models with each other in terms of maximum power. But when choosing acoustics for an amplifier (or vice versa), this parameter can be very useful: it is desirable that the maximum power of the speaker be at least twice as high as that of the amplifier. This will reduce the risk that a power surge will damage the speakers.
Max. impedance
The highest nominal load impedance (speaker) that the amplifier can handle.
Rated impedance (the term “impedance” is also used in acoustics) is one of the most important characteristics for the normal compatibility of acoustics and an amplifier: according to this characteristic, they must match. If the acoustic impedance is higher than the calculated one, the sound volume will be very low even if all other parameters match; if on the contrary, the sound will be distorted, and in the worst case, even the speaker may fail.
For a number of reasons, for car amplifiers, the maximum load resistance is traditionally indicated, that is, the maximum at which the device is still able to provide full sound volume. Standard values in car audio are 1, 2,
4 and
8 ohms. If the amplifier design does not provide resistance adjustment (see above), then the indicated maximum resistance is also the only permissible one. If there is such an adjustment, then the amplifier will be able to provide at least operation with the “neighboring” impedance value: for example, at a maximum resistance of 4 ohms, two-ohm speakers will also be normally supported. The specific “degree of freedom” in the adjustments for different models is different, this point should be clarified according to the official documentation.
