Rockford Fosgate PUNCH 4020 DSM manual N a M I C P O W E R M E a S U R E M E N T S

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D Y N A M I C P O W E R M E A S U R E M E N T S

About the Dynamic Power Measurements

The Audio Graph PowerCube is a test instrument used to measure the output of an amplifier in accordance with IHF-202 industry stan- dards. The IHF-202 standard is a dynamic power measurement and was developed as a means of measuring power in a manner that best represents the Real World operation of an amplifier. Many manufac- turers, including Rockford Fosgate, at times will measure amplifier power into a fixed resistor (4 Ohm, 2 Ohm). While this method is useful in some types of evaluation and testing, it is not representative of an amplifier that is connected to a speaker and playing music.

Music

Music is dynamic; the sound waves are complex and constantly changing. In order to simulate this, the IHF-202 standard calls for the input signal to the amplifier to be a 1kHz bursted tone. This signal is input (on for 20 milliseconds) and reduced 20dB for 480 millisec- onds. The signal is gradually increased in level until the amplifier's output exceeds 1% Total Harmonic Distortion (THD). At 1% distor- tion becomes audible, therefore, any power produced above that level is considered not usable. Many manufacturers represent their amplifiers' output power in excess of 10% distortion. They use many names for this measurement, such as Total Maximum Power or Maximum Output Power. This is not indicative of the actual usable output power.

Listening to Loudspeakers - Not Resistors

A loudspeaker is not a resistor. A resistor's value (resistance measured in ohms) is fixed. A loudspeaker's impedance is dynamic. It is constantly changing in value, dependent upon the frequency of the input signal. Therefore, measuring power with the amplifier loaded into a 4 ohm resistor is not the same as measuring power with the amplifier connected to a 4 ohm speaker. Most people do not listen to music through a resistor.

A 4 Ohm speaker may experience a drop in impedance 4-6 times lower than its nominal (printed) impedance. A speaker will also create phase shifts in the signal that is passed through it. These phase shifts happen because a speaker is an inductor (voice coil) and a capacitor (compli- ance of the surround/spider), as well as a resistor (voice coil wire).

To simulate a speaker the Audio Graph PowerCube measures output power into 20 different loads. It tests at 8 Ohms, 4 Ohms, 2 Ohms and 1 Ohm. Each of these impedances is also tested at –60° , –30° , 0° , +30° and +60° phase angles. These different impedances and phase angles represent the shifts in impedance and phase that can occur in a typical loudspeaker.

Appendix A

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Contents Punch 4020 DSM Practice Safe Sound T T I N G S T a R T E D T R O D U C T I O N AC C E S S O R Y PA C KEnergy Storage Capacitor PCH-C1 RO C K F O R D FO S G AT E AC C E S S O R I E STechnical Design Features TransanaTopaz Tracking Operation Pre-Amplifier Zone XCard Internal Crossover Punch 4020 D E S I G N F E AT U R E S Amplifier S TA L L AT I O N CO N S I D E R AT I O N S Mounting Location Battery and Charging R I N G T H E S Y S T E MPage I N G T H E Xcard PO W E R CO N N E C T I O N S M P L E W I R I N G D I a G R a M S Channel StereoChannel Stereo Front Mono Rear Channel Mono Channel STEREO/MONO Front Stereo Rear Troubleshooting RemedySymptom Diagnosis Remedy Engine Noise on About the Dynamic Power Measurements N a M I C P O W E R M E a S U R E M E N T SInformation Cubed SP E C I F I C AT I O N S R R a N T Y I N F O R M a T I O N Rockford Fosgate

PUNCH 4020 DSM specifications

The Rockford Fosgate PUNCH 4020 DSM is a remarkable amplifier designed to deliver high-quality sound and performance for car audio enthusiasts. This powerhouse amplifier stands out with its compact design and impressive specifications, making it an ideal choice for those looking to upgrade their vehicle's audio system.

One of the standout features of the PUNCH 4020 DSM is its 4-channel design, allowing it to power multiple speakers simultaneously. With a maximum power output of 40 watts RMS per channel at a 4-ohm load, this amplifier provides ample power to drive aftermarket speakers effectively, ensuring that users experience rich, detailed sound reproduction.

In terms of technology, the PUNCH 4020 DSM boasts a variable high-pass crossover and a low-pass crossover, enabling users to tailor the sound output to suit their preferences. The high-pass filter allows users to remove low-frequency noise, enhancing clarity in the midrange and high frequencies. Conversely, the low-pass filter can be utilized for subwoofers to ensure a deep, booming bass response without distortion.

Another key characteristic of this amplifier is its durable construction. Built with high-quality components, the PUNCH 4020 DSM is designed to withstand the rigors of car environments while maintaining reliable performance. The heatsink design promotes efficient heat dissipation, ensuring that the amplifier operates within safe temperature limits even during extended use.

The PUNCH 4020 DSM also features an easy-to-navigate wiring harness that simplifies installation, making it user-friendly for both seasoned audiophiles and those new to car audio upgrades. The amplifier's compact size allows it to fit in tighter spaces, offering more flexibility during installation.

Additionally, the PUNCH series is known for its signature Rockford Fosgate sound – a combination of precise engineering and performance-focused design. This results in an amplifier that not only looks good but also delivers a dynamic listening experience that can transform any vehicle into an audio haven.

Overall, the Rockford Fosgate PUNCH 4020 DSM is a versatile, powerful amplifier that offers a host of features and technologies geared towards enhancing audio performance. Whether you're listening to your favorite tunes on the road or hosting a car audio competition, this amplifier represents a high-performance solution that does not compromise on quality or sound precision.
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