Simple Surround Sound Speaker Circuit

Without investing in expensive new speakers this circuit mentioned in the article teaches how improve the surround sound system.

It makes use of a method known as the Hafler circuit which was created by David Hafler.

It just requires a turning a knob and arranging speakers to boost the level of sound coming from from the front and rear speakers.

What is a Surround Sound Speaker Circuit:

A surround sound circuit is a type of electrical circuit designed to enhance audio playback by creating a 3D and complete sound experience particularly in multichannel audio systems, such as home theaters.

The circuit is responsible for transmitting audio signals to several speakers placed carefully across a listening space.

This provides direction and intensity to the sound.

Working of Surround Sound Speaker Circuit:

Parts List:

It is simple to set up the Hafler circuit for use.

The L-R signals are the same for the rear left and right speakers.

One may leave off R1 if the sound quality is too poor, because they are not loud enough for the majority of audio systems.

It will be enough to use a single rear speaker as long as its impedance is 8 ohms or greater to avoid overloading the amplifier.

To improve reflective rebound place it best in the center facing up or toward the back wall.

How to Build a Surround Sound Speaker Circuit:

One must have some technical electronics knowledge and abilities to build a surround sound circuit.

Connecting the Hafler Circuit:

• Follow the Hafler setup when wiring the left and right rear speakers.
• As per the circuit design add potentiometer R1.

Connecting the amplifier:

• Connect the amplifier to the surround sound configuration circuit.
• The positive and negative terminals should be correctly matched.

Configuring the Rear Speakers:

• The amplifier should be connected to the rear end speaker.
• Place the rear speaker in the center of the back facing the back wall or upward.

Optional Switch for ON/OFF:

• If desire to manage the back channels one can connect an ON/OFF switch.

What is a Enhanced Surround Sound Speaker Circuit:

In short one can say an enhanced surround sound circuit is an audio circuit which provides more features and best audio experience than a standard surround sound design.

Working of Enhanced Surround Sound Speaker Circuit:

Parts List:

The circuit above might function better for rock music than jazz and it provides a better surround sound effect than the one before it.

To get the proper front to rear balance at the same time adjust potentiometers R1 and R2.

Depending on where the listener sits R1 and R2 settings can differ a bit.

By listening to the music adjust potentiometer R3 so that the front L and R signals mix quietly into the back speakers.

Install an ON/OFF switch at X if you want to stop music from mixing across the rear channels.

The rear speaker circuit (a) or (b) should be connected directly to the positive B terminals if the amplifier includes an A and B switch for an extra pair of speakers.

This makes turning the rear channels ON and OFF simple.

Formulas:

David Hafler is famous for his contributions to the fields of audio amplification and high quality audio systems.

In a surround sound speaker circuit an amplifier is normally used to drive several speakers ensuring proper speaker balance and protection of the overall sound quality.

Calculating Power:

To find out how much power each speaker will need:

P = VRMS²​​ / R

where,

• P is watts of power
• VRMS voltage across the speaker
• R is the speakers resistance from 4 or 8Ω as per the amplifier used.

Balance Adjustment Formula:

If you want to balance two channels using the potentiometer:

V_{out ​}= V_in​ × R_pot​​ / R_pot​ + R_fixed​

where,

• Vout is the amplifiers output voltage
• Vin is the voltage input from the audio source
• Potentiometer resistance is represented by Rpot.
• R is fixed if the value of a resistor is used.

Impedance Matching:

While using many speakers make sure the amplifier is receiving a proper impedance load.

For concurrent speakers:

1 / Rtotal ​= 1 / R​1​+1​ / R2​+…..

For speakers in series:

Rtotal​ = R1 ​+ R2​ + …..

Be sure that the amplifiers requirements are fulfilled by the overall impedance.

This simplified method provides users a basic understanding of how to set up a surround sound system and mix the music over many speakers.

For a complete and excellent system more components like crossover networks, equalizers and complex amplifier designs are required.

How to Build Enhanced Surround Sound Speaker Circuit:

To build a Enhanced Surround Sound Speaker Circuit follow the connection steps below:

Change the configuration of Hafler:

• Enhance the surround sound by modifying the Hafler Configuration based on the design requirements.

Potentiometer adjustments:

• Adjust potentiometers R1 and R2 at the same time to get the right front to rear balance.
• By listening to the music adjust potentiometer R3 so that the front L and R signals mix into the back speakers.

An optional switch to turn ON or OFF:

• For more control over audio mixing over the rear channels install an ON/OFF switch if one is not included.

Connection to Amplifier:

• For simple ON/OFF switching connect the rear speaker circuit straight to the positive B terminals of your amplifier if it has an A/B switch.

Conclusion:

Follow safety precautions at all times and check your wiring twice to avoid damage to components.

For the installation and configuration of the surround sound system if not familiar with technology think about asking an experienced person for help or seek an expert.

References:

Two channel audio surround sound circuit

Hafler circuit