Rockford Fosgate 50.2, 50.1 About the Dynamic Power Measurements, Music, Information Cubed

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DYNAMIC POWER MEASUREMENTS

DYNAMIC POWER MEASUREMENTS

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 standards. 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 manufacturers, 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 milliseconds. The signal is gradually increased in level until the amplifier's output exceeds 1% Total Harmonic Distortion (THD). At 1% distortion becomes audible, therefore, any power produced above that level is considered unusable. 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 (compliance 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.

Information Cubed

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The data acquired in the testing procedure is then

 

 

 

 

 

 

 

 

 

 

 

 

 

graphed in the form of a 3-dimensional cube, hence

 

 

 

 

 

 

Audio Graph – The PowerCube™

 

 

 

 

 

 

 

 

 

 

 

 

the name PowerCube.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MODEL BEING

VOLTAGE FROM

x2 = STEREO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TESTED

 

 

 

 

 

The Phase Angle is expressed on the horizontal axis,

 

 

 

 

 

BATTERY

MONO = BRIDGED MONO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Amplifier: PUNCH 200.2 14.4V x 2

Rated Power : 100 W @ 4 Ohms

 

 

the Output Voltage is presented on the vertical axis

 

 

 

 

 

 

Serial No:

 

 

 

 

 

 

 

 

and the Impedance is displayed on the Z axis. Output

 

 

Owner

 

: ROCKFORD CORPORATION

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Power, in watts, is listed on the left hand side for each

 

 

8Ω*–60°

85

W

 

 

 

 

 

 

 

impedance at each phase angle.

 

 

–30°

84

W

 

IN

 

 

50V

 

 

 

 

0°

84

W

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

POWER

 

 

 

 

 

 

 

 

 

 

30°

84

W

{WATTS

 

 

 

G E

 

 

 

 

 

N C E

60°

86

W

 

 

 

 

 

A

 

What is an Amplifier?

 

4Ω*–60°

162

W

 

 

 

 

30V

O L T

 

 

–30°

157

W

 

 

 

 

 

 

An amplifier by definition is a voltage generating

A

0°

156

W

 

 

 

 

 

V

 

D

 

 

 

 

 

T

 

30°

157

W

 

 

 

 

 

 

device, recreating the signal which is input to it

P E

60°

162

W

 

 

 

 

10V

P U

 

M

2Ω*–60°

273

W

 

 

 

 

 

T

 

identically

but

with increased

volume. It will be

I

–30°

258

W

 

 

 

 

8Ω

O U

 

connected

to

a reactive load

(the speaker). The

 

 

0°

251

W

 

 

 

 

4Ω

 

 

 

 

30

°

256

W

 

 

 

 

 

 

 

 

 

 

–60°(Cap)

 

 

2Ω

 

 

 

 

 

 

 

 

60°

271

W

 

0°

 

 

 

impedance of this load and phase of the signal

 

 

1Ω*–60°

390

W

 

 

1Ω

{

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

–30°

356

W

 

 

(Ind) +60°

 

 

passing through the load will vary, dependent upon

 

 

0°

346

W

 

PHASE{ANGLES

 

Impedance

 

 

the frequency of the input signal (music).

 

 

30°

352

W

 

 

 

 

 

 

 

 

 

60°

390

W

 

 

 

 

 

 

 

 

 

 

 

 

• Example of a Punch 200.2 PowerCube

 

 

 

 

Therefore, a perfect amplifier will be able to maintain

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

the same output voltage regardless of load charac-

 

 

 

 

 

 

 

 

 

 

 

 

 

teristics and will not alter the signal it is reproducing. A perfect amplifier when measured by the Audio Graph PowerCube would present data that forms a perfect cube. Unfortunately, amplifiers are not perfect. The laws of physics generally prevent it. A great amplifier is about the best one can hope to attain.

As you can see by the PowerCube and as you will experience by listening, your Punch amplifier is a GREAT AMPLIFIER!

– 45 –

Image 48
Contents power powernew chrome heatsink 50.1PRACTICE SAFE SOUND TABLE OF CONTENTS G E T T I N G S TA R T E DPUNCH AMPLIFIER ACCESSORY PACK Punch PowerINTRODUCTION TO 50 SERIES Punch PowerTECHNICAL DESIGN FEATURES Stereo Pass-Thru DSM Discrete Surface Mount TechnologyXCard Internal Crossover Balanced Line Inputs NOMAD NOn-MultiplyingAdvanced DecisionITS Increased Thermal Stability 50.2 DESIGN FEATURES M P L I F I E R 50.1 DESIGN FEATURES Page INSTALLATION CONSIDERATIONS Tools NeededBATTERY AND CHARGING MOUNTING LOCATION STrunk Mounting Passenger Compartment MountingWIRING THE SYSTEM USING PASSIVE CROSSOVERS TABLE OF CROSSOVER COMPONENT VALUES Speaker Impedance6dB/Octave Low-Pass FreqUSING THE XCARD CUSTOMIZING THE XCARDHigh-Pass Low-PassXCARD RESISTOR CHART Butterworth Alignment Q =1% resistors used with 0.047mF capacitors Butterworth Alignment Q =50.2 INSTALLATION 50.2 Power Connections Option #150.2 Power Connections Option #2 Stereo Operation Stereo/Mono OperationLeft Phase Switch set to Right Phase Switch set toBridged Operation EZ-BridgedOperationLeft Phase Switch set to Right Phase Switch set toUSING THE 50.2 SIGNAL SWITCHING NETWORK 50.2 bypasses the circuitry of XCard 1 and XCard 50.2 uses output from XCard Pass-Thru uses output from XCard50.2 bypasses the circuitry of XCard 50.2 uses output from XCard 1 and XCard Pass-Thru bypasses XCard 1 and XCardUSING THE 50.2 BALANCED LINE INPUTS Connecting the BLTLevel Setting the BLT Performance CharacteristicsDisconnect Speakers from the AC Voltmeter set to AC Volts50.1 INSTALLATION 50.1 Power Connections Option #150.1 Power Connections Option #2 – 26 –Mono Operation Phase Switch set toPhase Switch 50.1 #1/2 set to Phase Switch 50.1 #1 set to Phase Switch 50.1 #2 set toStereo/Mono Operation XCard 50.1 #1/#2 set to Full RangeBridged Mono Operation Phase Switch 50.1 #1 set toPhase Switch 50.1 #2 set to U S I N G T H E 50.1 SIGNAL S W I T C H I N G N E T W O R K“Audiophile Bypass” the Configure a 12dB per octave filter for the Xover is set to 12dBPass-Thru has Full Range output only LOUDConfigure a 24dB per octave filter for the • Xover is set to 24dBPass-Thru has Full Range output only SYSTEM DIAGRAMS 100 Watt System rated @ 4 ohmsTotal Power Delivery RMS 150 Watt System rated @ 4 ohms Total Power Delivery RMSTweeters 400 Watts300 Watt System rated @ 4 ohms Total Power Delivery RMSTweeters 400 Watts500 Watt System rated @ 4 ohms Tweeters400 Watts MidrangeROCKFORD FOSGATE ACCESSORIES NOISEBalanced Line Transmitter FG-BLT Energy Storage Capacitors XCard Crossoverspunch TROUBLESHOOTING SymptomDiagnosis RemedySymptom DiagnosisRemedy Speaker Output LowSymptom DiagnosisRemedy Low or distorted output from theQUICK CHECK FOR TROUBLESHOOTING CAR AUDIO SYSTEMS AUTOSOUND 2000sPreface Noise OverviewTime for Processors SummationDYNAMIC POWER MEASUREMENTS About the Dynamic Power MeasurementsWhat is an Amplifier? Music50.2 SPECIFICATIONS Specifications subject to change without notice50Watts 90Watts 150Watts 300Watts 25Watts 50Watts 100Watts 200 Watts50.1 SPECIFICATIONS Specifications subject to change without notice100Watts 200Watts 325Watts 650Watts 50Watts 100Watts 200Watts 400 WattsLIMITED WARRANTY INFORMATION Length of WarrantyWhat is Covered What is Not CoveredN F O R M A T I O N INTRODUCCIÓN UBICACIÓN DE LOS AMPLIFICADORESMaletero HabitáculoESPAÑOL Operación mono/estéreoInstallation INTRODUCTIONMONTAGE Montage dans le coffreFRANÇAIS Opération stéréo/monoTri-modeInput EINLEITUNG EINBAUORTIm Fahrzeugkofferraum Auf der BeifahrerseiteDEUTSCH Linken Phasen Schalter auf 0 stellenStereo/Mono Betrieb Installazione INTRODUZIONEDOVE POSIZIONARLO Nel BagagliaioITALIANO Stereo/Mono OperationFase sinistra dellinterruttore posizionata su MADE IN THE USA