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SR 4.300 Amplifier | 520 W | 4×85 W | D-class

Audison SR 4.300 4-channel amplifier with crossover and great power packed into ultra-compact dimensions (85 W x 4  4Ω)

SR line, perfected by taking full advantage of the capabilities of the latest amplification devices. After numerous listening tests with professionals and enthusiasts, Audison's R&D team decided to adopt a new class D technology called ADT (Audison D-Class Technology) for this line of amplifiers, which has made it possible to considerably reduce their size, totally preserving the audio performance that characterises every Audison design.

As far as the electronic design is concerned, every aesthetic and functional detail of the Audison SR 4.300 has been taken care of, resulting in a compact amplifier made of extruded aluminium with rounded corners, which facilitates the installation of the product in narrow spaces. Thanks to the generous heat sinks on the two short sides of the amplifiers, there is no need for internal cooling fans, which often cause noise and dust accumulation.

In keeping with tradition, the SR amplifiers confirm their vocation for versatility by including on all models a complete filter section, suitable for any kind of audio system configuration. The controls, protected by a satin-finished aluminium panel, are located on the top panel of the amplifier, so that they can be easily reached from above, even after the product has been installed. When the system includes an Audison bit processor, the filter section can be totally excluded.

Audison USS

Thanks to the integration of Audison USS (Universal Speakers Simulator) technology in the high level inputs, the SR amplifiers can also be conveniently connected to OEM sources equipped with the 'speaker load detection' function, which monitors the presence of a low impedance load enabling the audio outputs.

Audison SR 4.300 allows multiple connectivity

All models have balanced high-level inputs for connecting to the OEM headunit speaker output and a low-level RCA for after-market speakers. When using the high-level input, the ART (Automatic Remote On/Off) function can be enabled to control the amplifiers' power-up with the headunit's power button. In addition, there is a remote IN / OUT socket to allow control of multiple amplifiers in cascade that turn on when needed.

Through the PRE-OUT signal using the Speaker-IN socket it is possible to interface the amplifier with OEM sources that only have amplified outputs, allowing for system expansion.

Amplifier Tech Data

Channels 4
Class D-Class
Hi Level Input Yes
Low Level Input Yes
Digital Input No
Power supply voltage / fuse 11 ÷ 15 VDC / 1 x 30A
Operating power supply voltage 6.5V ÷17 VDC
Idling current 1.6 A
Idling current when off 0.03 mA
Consumption @ 14.4 VDC, 2Ω, Max Musical Power 25 A
Remote OUT 6.5 ÷ 15 VDC (150 mA)
Remote IN 6.5 ÷ 15 VDC (1 mA)
ART - Automatic Remote Turn on/off from OUTPUT BTL speakers (Selectable) 1.5 ÷ 7 VDC

Amplifier Stage

Distortion - THD @ 100 Hz, 4Ω, 70% Rated Power 0.03%
Bandwidth A 10Hz ÷ 35 kHz
S/N ratio A 100 dBA
Damping factor A 150
Input sensitivity Pre-In 0.2 ÷ 5 VRMS
Input sensitivity Speaker-In 0.8 ÷ 20 VRMS
Total Power RMS 520 W
Minimum load impedance @4Ch: 2Ω
@ 3Ch: 2Ω + 2Ω + 4Ω
@ 2Ch: 4Ω
Output Power (RMS) @14.4 VDC, 1% THD 4Ch 85 W x 4 (4Ω)

4Ch 130 W x 4 (2Ω)

3Ch 80 W x 2 (4Ω) + 250 W x 1 (4Ω)

3Ch 130W x 2 (2Ω) + 260 W x 1 (4Ω)

2Ch 250 W x 2 (4Ω)
Adjustable Crossover Yes

CEA Specifications

Output power @ 4Ω, 1% THD+N, 14.4 V Output power @ 4Ω, 1% THD+N, 14.4 V: 75 W x 4 Ch
SN ratio (ref. 1W output) SN ratio (ref. 1W output): 82 dBA


Input Type Pre-In / Speaker-In
Filters Outputs PRE OUT full range (Input A)
Filter Pass A Ch Filters: - Full Hi-pass: 50 ÷ 3.2k Hz @ 12 dB/Oct.
Filter Pass B Ch Filters: - Lo-pass: 50 ÷ 3.2k Hz @ 12 dB/Oct.
Filter Pass C Ch Filters: - Full Hi-pass: 50 ÷ 3.2k Hz @ 12 dB/Oct.
Filter Pass D Ch Filters: - Lo-pass: 50 ÷ 3.2k Hz @ 12 dB/Oct.
Channel Mono A/B Ch MONO IN (on/off) Yes
Inputs/Outputs Bass Boost B Ch (0 ÷12) dB


Weight 1.56 kg


SR 4.300
Dimension A 190 mm
Dimension B 160 mm
Dimension C 155 mm
Dimension D 135 mm
Dimension E 47.5 mm


SR 4.300
USS - Universal Speakers Simulator

Thanks to the integration of Audison USS technology (Universal Speakers Simulator) in the high-level inputs, the SR amplifiers can also be appropriately connected to OEM sources featuring the “speaker load detection” function that monitor the presence of a low-impedance load to enable audio outputs.

SR 4.300
ADT - Audison D-Class Technology

Class D amplifiers are also called “switching amplifiers”, since their efficiencies are arrived at by rapid on and off switching of the output transistors. Audison Class D uses a much higher switching frequency than most other amplifiers. You might think the switching frequency for all Class D amps are the same, but Class D chipsets allow significant latitude in many design aspects, such as switching frequency and timing. Most companies use as low a switching frequency as possible – this makes the timing easier to manage, and allows the use of lower-precision components which cost less. ACD uses a switching frequency twice as fast as many other modern Class D amplifiers. Higher switching frequencies require incredibly precise timing, which require higher-tolerance components to be used in order to keep the timing pulses from overlapping (that causes catastrophic failure of the output transistor). Audison uses very high-tolerance component parts to keep the timing correct even during temperature extremes (temperature changes shift the values of analog components). To Audison, this is worth the cost, since the higher switching frequency of Audison Class D moves noise much farther away from the audible band. Audison Class D also uses a steeper 4th-order analog lowpass filter, rather than the simpler 2nd-order lowpass filters usually used in competing designs. The steeper filter will keep noise much lower in amplitude – which is good for controlling EMI and for preventing infrasonic noise getting to the tweeters. It also keeps phase shift outside the audible range. The cost is higher – twice as many components are needed for a 4th order filter compared to the usual 2nd-order filter, and each output channel needs its own filter – but Audison determined through exhaustive listening testing that this design was the best-sounding approach.

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