Subwoofer Plate Amplifiers: Explained

The type of amplifier used in audio systems defines the quality of music we hear.

Yes, that’s right, the quality and the type of amps define the quality of music your subwoofer and speakers will deliver.

In this article, we will discuss plate amps, their uses, and their benefits to audio systems.

What are Plate Amplifiers in Subwoofers?

Plate amplifiers are generally built on flat boards specially designed to be installed inside the enclosures of subwoofers and speakers.

The flat boards or plates used to make these powered amps are typically made from metals such as steel and aluminum

Most plate amps include a face plate (front plate) with controls, inputs, outputs, a power connection, and exposed components on the other side (to the back).

The crossovers usually strip higher frequencies out of the signals that they amplify which helps you in varying the crossover’s active point.

These amps can typically accept both line-level and speaker-level signals and pass them back to the speakers by altering the bass portion.

The phase or delay controls in plate amps help alter the bass signal to match up with the provided speaker systems.

Moreover, the volume controls allow them to modify their output level to blend perfectly with the response of the sound system.

In some cases, you can manually mount plate amps inside the enclosures of your existing passive subs to convert them into active or powered units.

Most plate amps have restricted frequency responses, making them ideal to be used as subwoofer amplifiers.

This is because, the musical amplifiers are capable of reproducing frequencies ranging from 20 Hz to 20,000 Hz. It typically covers the entire range (frequency range) of human hearing and musical tones.

On the other hand, plate amplifiers usually roll off their response on frequencies over 200 hertz which limits them to use with subwoofers.

To make it simple, most plate amps typically do not reproduce frequencies above 150 Hz to 200 Hz which are ideal frequency crossover settings for a subwoofer.

Where do you use Plate Amplifiers?

Plate amps are used in various audio applications such as small home cinema setups, home theaters, studio monitors, DJ workstations, computer workstations, etc.

Additionally, musicians prefer installing plate amps inside their speakers and subwoofer cabinets to deliver punchy, crisp sound quality.

Plate amps can include multiple channels for different audio systems.

To match the power for a woofer and tweeter, a 2-channel plate amplifier module provides separate low and high output sections.

Similarly, to control a full-range speaker pair and subwoofer you can use a 3-channel plate amplifier.

Finally, plate amps can be used to upgrade your existing sound system or to simply build your own high-quality integrated powered subwoofer speaker system.

Most sound lovers are DIY hobbyists who love to build their own subwoofers.

They prefer installing plate amps to their speaker and subwoofer units by cutting a hole in the back panel of their unit and screwing the amp into it.

This installation method hides the exposed components of the plate behind the panel and leaves the controls and inputs on the outer side.

The interior side of the plate amplifier typically includes a pair of speaker terminals.

You can connect the amplifier’s main output to the subwoofer driver.

Role of DSP (Digital Signal Processing) in Plate Amp

To get the maximum performance out of your active subwoofers and speakers, installing a DSP module kit is highly recommended by the experts.

A plate amplifier usually allows you to control and make adjustments with delays, crossovers, and co, but with the help of a DSP module kit you can adjust further details.

It will enable you to adjust further details such as phase shifting and digital filters.

Signal Conditioning: Before amplification, the audio signal may need some conditioning. DSP can clean up the signal by filtering out unwanted noise or interference.

Equalization (EQ): Digital Signal Processing allows for precise equalization to tailor the frequency response of the speaker. For instance, if a subwoofer has a natural dip in response at a certain frequency, DSP can boost that particular frequency to achieve a flatter response.

Crossover Management: In multi-driver speaker systems, it’s essential to direct specific frequency ranges to the appropriate driver (e.g., lows to the woofer and highs to the tweeter). DSP can be used to implement and control these crossovers digitally, ensuring sharp cutoffs and minimizing phase issues.

Dynamic Range Compression: To prevent potential damage to the speaker or to avoid distortion, DSP can be used to apply dynamic range compression. This ensures that the audio signal remains within safe limits for the speaker.

Limiting: Similar to compression, DSP can also apply limiting to the audio signal. This ensures that sudden spikes in the audio signal, which could damage the speaker, are kept in check.

Phase Alignment: Especially in multi-driver systems or when multiple speakers are used in a setup, ensuring that all speakers are phase-aligned is crucial. DSP can adjust the phase of the signal to ensure coherent sound reproduction.

Time Delay: In setups where speakers are placed at different distances from the listener, DSP can introduce time delays to ensure that sound from all speakers reaches the listener simultaneously.

Feedback Suppression: Particularly in live sound or environments prone to feedback, DSP can dynamically identify and notch out frequencies causing feedback.

Protection Circuits: DSP can monitor the temperature and excursion of the drivers and reduce the input level or apply other protective measures if it detects that the speaker is approaching unsafe conditions.

Room Correction: Some advanced plate amplifiers with DSP capabilities can analyze the acoustics of the room and adjust the signal accordingly to compensate for room modes or other acoustic anomalies.

User Customization: DSP allows for user customization. Users can tweak the sound according to their preferences, adjust EQ settings, set crossover points, and more, all through a digital interface.

In essence, DSP in a plate amplifier provides a combination of sound shaping, protection, and optimization tools that are essential for modern loudspeaker performance and longevity.

Final Thoughts

To get the most out of your subs plate amps can be an ideal choice to balance the deep thumping bass notes with different audio notes.

Most subwoofer plate amplifiers include auto On/Off, level inputs (high and low), balance inputs (balanced and unbalanced), DSP, adjustable crossover frequency, etc., which makes them a perfect fit for audio systems.

In most cases, plate amps are usually mounted inside the enclosure of a subwoofer, to drive them and reproduce bass and subsonic frequencies.

Armed with a Diploma in electrical engineering and a remarkable 12 years of expertise, he excels in rejuvenating music systems, washing machines, dryers, and laundry-related appliances. Manish's profound insights and practical know-how establish him as a credible authority in appliance and music system repairs. Contact: manish.singh (at) He's always ready to lend a helping hand!