Understanding the Function of the Pre-Out Port in AV Receivers
When setting up a home theater system, the back panel of an AV receiver can look intimidating with its myriad of inputs and outputs. Among these, the Pre-Out port often confuses many users. This blog explains what a Pre-Out port is, its function, and how you can use it to enhance your audio experience.
The Pre-Out (preamplifier output) is an analog audio output on AV receivers that sends an unamplified line-level audio signal to an external amplifier. Unlike the speaker outputs, which provide amplified signals to drive speakers directly, the Pre-Out port outputs a signal before amplification. This means the signal still requires an external power amplifier to drive the speakers.
Why Use the Pre-Out Port?
Most modern mid-range and high-end AV receivers come equipped with Pre-Out ports. The key advantage of using Pre-Outs is that they allow you to connect an external power amplifier to drive your speakers. This is particularly useful if your built-in AV receiver amplifiers donβt provide enough power for high-end or power-hungry speakers.
By connecting an external amplifier via the Pre-Out, you get:
More amplification power for your speakers
Improved sound quality across all frequency ranges β deeper bass, clearer midrange, and crisper highs
The ability to bi-amp your front speakers by connecting a 2-channel amplifier to the front left and right Pre-Outs
The option to use a multi-channel external amplifier to power your entire surround sound system
Common Uses of Pre-Out Ports
Subwoofers: Nearly all home theater receivers have a dedicated subwoofer Pre-Out. This allows connection to a powered subwoofer that has its own built-in amplifier, ensuring tight and authoritative bass by independently amplifying the low-frequency effects (LFE) channel.
Additional Amplification: Audiophiles often use Pre-Outs to connect external tube amplifiers or other high-fidelity amplifiers for better sound quality.
Multi-room or Zone Setups: Pre-Outs can be used to send audio to a separate zone or room.
Dolby Atmos and Height Channels: Many high-end AV receivers offer Pre-Outs for height channels, allowing users to add external amplifiers for immersive surround sound without upgrading the entire receiver.
How to Connect and Use Pre-Outs
Connect the Pre-Out ports on your AV receiver to the analog audio inputs on your external amplifier using appropriate cables (RCA, XLR, etc.).
Turn off the speaker assignments on the AV receiver for channels connected to external amps to avoid signal conflicts.
Match the impedance of your speakers and amplifier to prevent damage.
Use good quality cables to minimize signal loss.
Adjust the volume on the external amplifier carefully to avoid distortion.
You may need to rerun room correction or calibration after adding external amplifiers.
Recommended AV Receivers with Pre-Outs
For those with mid to high-end speakers, AV receivers with Pre-Outs for front left/right and subwoofer channels are highly recommended. Popular models include:
These models provide flexibility to expand your home theater system with external amplification for superior sound performance.
The Pre-Out port on AV receivers is a versatile feature that allows you to enhance your home theater audio by adding external amplifiers. Whether you want louder, cleaner sound or want to bi-amp your speakers, utilizing Pre-Outs can significantly improve your listening experience.
If you need help selecting an AV receiver or amplifier for your setup, professional advice can ensure you get the best configuration for your needs.
