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)”.
Bridge connection
Rated power delivered by the amplifier to a load connected in a bridge circuit. For more information about the rated power, see "Nom. channel power (at 1 Ohm)”.
With a bridged connection, the speaker is connected not to one channel, but to two at the same time — the “positive” connector of one channel and the “negative” connector of the other are used. If the amplifier has a similar format of operation, then such a pair of channels operates in antiphase, due to which the power is summed up. This allows you to connect speakers to the amplifier, the power of which is twice the nominal power of the device: for example, at 150 watts per channel, 300 watts of acoustics can be bridged. If there are 4 or more channels, it becomes possible to use several speakers according to the "bridge" scheme. This is usually directly indicated in the specifications — for example, the entry "2x300 W" in the "Bridge connection" item means the ability to work with two speakers, each with 300 W.
The requirements for load resistance when connecting with a bridge are the same as for conventional; see "Maximum Resistance" for details.
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.
Frequency range
The range of audio frequencies that the amplifier is capable of processing. The standard hearing range of the human ear is 16-20,000 Hz, but for some people these limits can be much wider. In addition, low-frequency vibrations, already inaudible to the ear, but extremely close to the lower threshold of audibility, are perceived by the entire surface of the body at high sound power, which creates the impression of the most saturated sound (although care must be taken with this, because infrasound can have a bad effect on well-being).
In general, the wider the frequency range of an amplifier, the richer the sound it can provide. However, this is not an unequivocal guarantee of high sound quality — a lot also depends on the amplitude-frequency characteristic, signal-to-noise ratio (see below) and other features of a particular device. Yes, and the connected speakers must also correspond to this range — otherwise the signal will be "cut off".
Also note that many monoblocks (see "Number of channels") have an upper range limit of only a few hundred Hz — these models are designed for use with subwoofers, and high frequencies for them would be an unnecessary overkill.
Signal-to-noise ratio
One of the main parameters that determine the sound quality of the amplifier as a whole: it describes the ratio of the useful signal (in other words, “clean” sound) and various extraneous noises. This takes into account almost all noise — both due to external causes (for example, electrical "pickup"), and created by the device itself (for example, due to heating during operation). Accordingly, the higher the signal-to-noise ratio, the less audibility of various interferences and the clearer the sound is obtained (of course, under normal operating parameters). The average for car audio is 95-100 dB, but in advanced models this value
can be significantly higher.
At the same time, this parameter is not critical for monoblocks designed for subwoofers — most of the interference is high-frequency and will simply not be heard on the low-frequency speaker. The sound quality in this case is highly dependent on the characteristics of the speaker (much more than in multi-channel models), and is weakly related to the “noiselessness” of the amplifier.
Fuse rating
The rating of the fuse installed in the amplifier is the current strength, at which the fuse operates, opening the circuit and de-energizing the device in order to avoid unpleasant consequences (see "Protection — Short circuit protection"). In some models, several fuses can be installed — in this case, this is usually directly indicated in the characteristics, and the current required to operate the protection corresponds to the sum of the ratings. For example, the rating marked "4x25 A" corresponds to four fuses that operate at a current strength of more than 100 A.
This parameter determines, first of all, the features of the power connection: it is desirable that the fuse in the corresponding section of the on-board network of the car be of a higher rating than in the amplifier, otherwise it may burn out at a current that is quite normal for the device. In addition, the fuse rating is related to the power rating of the amplifier and can be useful if you have doubts about the reliability of the data specified by the manufacturer. There are special formulas that allow you to calculate the maximum possible rated power depending on the fuse rating and device class (see above).
