This calculator has two primary functions: The 'Headphone Resistor Network Calculator' page will help you determine the optimum resistor values for a headphone to speaker interface which will electronically match your headphones to a speaker amplifier using a resistor network. The headphone 'Power Calculator' page will calculate headphone power, current and voltages. The resistor network used in this app is a simple two resistor L-pad attenuator and is the most commonly recommended headphone-to-speaker-amp resistor network interface.

Headphone Resistor Network Calculator Instructions

1. Enter your Headphone's Impedance rating, your Amplifier's Speaker Load rating (usually 4 or 8 ohms) and the Amp's Output Impedance.

2. Click the 'Calculate' button. Any time a value is changed the 'Calculate' button must be clicked again.

Effective Speaker Load is the load your amplifier 'sees.' The goal is to match this to your amplifier's speaker load rating (usually 8 ohms).

Attenuation is the reduction in decibels the resistor network provides.

Eff Phone Impedance is the Effective Headphone Impedance.

3. For Additional Network Calculations enter your headphone sensitivity in dB/mW and amplifier's output voltage and click 'Calculate'.

Amplifier Power is the amp output in watts into the Effective Speaker Load.

Amplifier Current is the amp output in amps into the Effective Speaker Load.

Amplifier Loudness is the dB level when driven into the Effective Speaker Load.

Headphone Power is the milliwatts going through the headphones.

Headphone Current is the milliamps going through the headphones.

Headphone Loud is the loudness of the headphones in dB SPL (decibel Sound Pressure Level).

R2 Dissipation is the power in milliwatts used up by resistor R2.

R3 Dissipation is the power in milliwatts used up by resistor R3.

R2 Voltage Drop is the drop in voltage across resistor R2.

R3+HP Voltage Drop is the drop in voltage across resistor R3 and the headphones.

Headphone Power Calculator Instructions

1. Enter the values in yellow including your Headphone's Impedance rating and Sensitivity rating in dB/mW (decibel per milliwatt). If your headphone manufacturer lists the sensitivity rating in dB/V (decibel per volt) select the dB/V CheckBox. To calculate the power required to achieve a loudness value enter the desired loudness in dB. To calculate how loud an amplifier will drive your headphones enter the amplifier's Vrms rating.

2. Click the 'Calculate' button. Any time a value is changed the 'Calculate' button must be clicked again.

Headphone Sensitivity is the equivalent of what you entered in the yellow box--if you enter sensitivity in dB/mW (CheckBox not checked) it will be converted to sensitivity in dB/V. If you enter dB/V and check the CheckBox then it will be converted to dB/mW.

Power @ 1Vrms is the power in milliwatts running through the headphones when a 1 volt (root-mean-square averaged) audio signal is applied to them.

Current @ 1Vrms is the current in milliamps running through the headphones when a 1 volt audio signal is applied.

What's Required to Reach a Loudness Level

Enter your Target Loudness Level in dBSPL (decibel Sound Pressure Level) and click any 'Calculate' button.

Power Required is the amplifier output power in milliwatts required to get your headphones to the Target Loudness Level.

Voltage Required is the amplifier output voltage in volts required to get your headphones to the Target Loudness Level.

Current Required is the amplifier output current in milliamps required to get your headphones to the Target Loudness Level.

How Loud Will an Amplifier Drive Your Headphones

Enter your amplifier's Vrms output rating in volts and click any 'Calculate' button.

Headphone Loudness is how loud your headphones will play in dBSPL (decibel Sound Pressure Level).

Amplifier Power is the amplifier power output in milliwatts.

Amplifier Current is the amplifier current output in milliamps.