Pioneer GM-DX874 amplifier

Pioneer GM-DX874 4-channel car amplifier

High-definition audio offers sound reproduction with extraordinary realism. The Pioneer GM-DX874 is an extremely efficient Class D digital amplifier with high-quality audio components that have been fine-tuned to offer excellent sound quality. Gold RCA connectors and high-capacity audio source capacitor ensure stable power supply even at high output power. To prevent the circuit from shutting down, the Pioneer GM-DX874 digital amplifier circuit includes a "protection control system" that senses its internal temperature and automatically adjusts the input level accordingly. Stable and durable circuits reduce the risk of high input power of the unit to achieve a 1 Ω connection. This design increases the flexibility of connecting multiple subwoofers to a system. For extra flexibility, easy installation is guaranteed thanks to "Automatic Signal Sensing and Turn-On", which automatically detects the input signal and switches the amplifier on and off when connected via the speaker line input. Variable LPF and HPF means you can adjust the sound frequency more according to the speaker, subwoofer characteristics and personal listening preferences. The GM-DX874 LPF and HPF is adjustable from 40 Hz to 500 Hz. The GM-DX874 also includes a Bass Boost wired remote control. The GM-DX874 has an elegant design thanks to the aluminum hair panel on the top plate, which enhances the highly positive feeling of the design and a total of 1200W.

NOTE: Products with the Hi-Res Audio logo conform to the Hi-Res Audio standards of the Japan Audio Society. Logo used under license from Japan Audio Society.

Catalog number	GM-DX874
Brand	Pioneer
Links	Official web presentation
Number of amplifier channelsAmplifiers are divided into: - Monoblocks - 2-channel - 3-channel - 4-channel - 5-channel - 6-channel - multi-channel Each channel is used to power one speaker for the coaxial type, or one side if they are component speakers. Monoblock type amplifiers are mainly used for subwoofers. 2-channel are suitable for both subwoofers and, for example, the front pair of speakers in a car. 3-channel is used for front or rear speakers + subwoofer. 4-channel are used for front + rear speakers or 1 pair of speakers + subwoofer. 6 or 5-channel are used for 2 pairs of speakers + subwoofer, most often. Bridging means connecting the amplifier to a bridge, using the + pole from one channel and the - pole from the other channel. In most cases this is shown as "BRIDGED" on the amplifier.	4
Energy class of the amplifierAmplifiers are divided into two basic classes: analog and digital . Analog amplifiers (A/B) have higher consumption requirements, but usually have a more natural sound. Digital amplifiers (D) have significantly lower consumption and higher efficiency, but the sound may not be as faithful as with classic analog amplifiers.	FD
RMS power into 4 ΩRMS power when loading speakers or subwoofer at 4 Ω. RMS power is the constant power of the amplifier and is one of the most important parameters when choosing an amplifier.	4 x 100 / 2 x 300 W
RMS power into 2 ΩRMS power when loading speakers or subwoofer at 2 Ω. RMS power is the constant power of the amplifier and is one of the most important parameters when choosing an amplifier.	4 x 150 W
RMS power into 1 ΩRMS power when the subwoofer is loaded at 1 Ω. RMS power is the constant power of the amplifier and is one of the most important parameters when choosing an amplifier. When connected to 1 Ω, significant heating of the amplifier may occur.	4 x 125 W
Max. (maximum) power at 4 ΩPeak performance "Max." , which the amplifier can develop for a very short time. A relatively unimportant parameter. It is mainly a marketing move to attract customers to high numbers.	4 x 200 W
Max. (maximum) power at 2 ΩPeak performance "Max." , which the amplifier can develop for a very short time. A relatively unimportant parameter. It is mainly a marketing move to attract customers to high numbers.	4 x 300 W
Low-pass filter (LPF)LPF / LP or "low pass filter" offers the possibility to adjust the amplifier using a potentiometer so that the lower band plays only the frequencies in a certain band that you need. This filter is used to adjust the frequency range for the subwoofer, so that it does not overload or distort the sound. Example: Amplifiers most often have an LPF from 20 to 300 Hz. We recommend setting this potentiometer in the range of 45-80 Hz.	Variabilní
High pass filter (HPF)HPF / HP or The "hi pass filter" offers the option of setting the amplifier using a potentiometer so that medium, possibly mid-bass and treble frequencies play upwards from a certain frequency. Example: Amplifiers most often have an HPF from 40 to 300 Hz. If we set the potentiometer to a value of approx. 150 Hz, the sound will be clipped so that it plays frequencies from 150 Hz up to the maximum upper limit of the entire frequency range of the amplifier, perhaps up to 20,000 Hz. We recommend setting this potentiometer in the range of 80-160 Hz. Thanks to this setting option, the speakers can handle a higher performance, as you will not overload them with bass in the lower frequency range.	Variabilní
Frequency rangeThe ability of the amplifier to reproduce the signal from the lowest frequency to the highest = faithfully reproduce the sound in a specific frequency band. Professionally: In the frequency range from 40 to 16,000 Hz, the vast majority of fundamental and overtones (harmonics) of all musical instruments are found. We are interested in the course of the radiated sound pressure in this range of frequencies when the loudspeaker system is supplied with constant power. We call this course the frequency characteristic, which tells us the level of radiated sound pressure in decibels (dB) depending on the frequency. The frequency characteristic of a speaker or speaker system can be expressed most succinctly with a graph. Mostly, however, the frequency characteristic is indicated by indicating the maximum tolerance of the sound pressure in the given frequency range, e.g. 50 to 15,000 Hz -+ 6 dB. Since the frequency characteristics of loudspeakers and systems in general are quite uneven, some manufacturers do not even specify this maximum tolerance of sound pressure in decibels in their catalogs for reasons of prestige. Data impoverished in this way is unfortunately worthless. What is valid is that the manufacturer offers a speaker system with a frequency range of 30 to 20,000 Hz, if he is worried about stating the maximum unevenness of the sound pressure in this range, because he can have a tolerance of, for example, +- 20 dB. The unevenness or undulation of the frequency curve in good speaker systems for high-quality music performance should not exceed +-3 dB in the 80 to 12,000 Hz band and +-6 dB in the 40 to 16,000 Hz band. Greater unevenness already depletes or emphasizes certain tonal areas, which can cause audible or even disturbing distortion. The proportion between fundamental tones and higher harmonics also changes, thereby changing the color of the sound, and individual musical instruments as well as the entire musical image sound unnatural.	10 - 50 Hz
Harmonic Distortion (THD)Total harmonic distortion indicates how much the input signal is distorted in the amplifier. Distortions appear as overtones contained in the output signal. The proportion of originally absent parts of the signal is given as a percentage, typical values are between 0.001% and 0.5%. Distortion is measured in their power band. If it exceeds the limit of 0.7% from a certain power, it is the value of the output power of the given amplifier, from which it no longer plays without distortion and from which the distortion usually increases steeply, so that no further increase in power can be counted on. The lower the value, the better.	< 0,05 %
Signal-to-noise ratioThe signal-to-noise ratio means that the output signal always contains noise. The signal-to-noise ratio expresses how much of this noise is compared to the useful signal. The so-called A value is given, which does not take deep and very high frequencies into account. This corresponds to the characteristic of human hearing, which is not so sensitive to deep frequencies, especially below 1 kHz. The higher the value, the better the amplifier is.	> 95 dB
Remote control included in the packageSome models of amplifiers also come with wired remote controls in the package, which on one side plug into the amplifier and on the other side you have a potentiometer that you can place anywhere in the cabin. A common place to place the remote control is under the steering wheel. The advantage is the regulation of power, and therefore volume, depending on driving conditions and the mood of the crew in the car.	Ano
Dimensions of the amplifier	252 x 215 x 60 mm