ZKMT21 100W Bluetooth Amplifier Board - 2.1 Channel HiFi Subwoofer Amp

In this review the ZKMT21 100W Bluetooth amplifier board is evaluated for hobbyists and small home audio projects who need a compact, powerful 2.1 solution. The bottom line: it suits builders who want reliable Bluetooth 5.0 streaming plus AUX input and dedicated subwoofer output in a board that is simple to install and adjust. The reviewer found the amp delivers solid performance for driving small to medium speakers and offers protection features that make it a dependable choice for custom enclosures and retrofit sound systems.

Key Features

• Bluetooth 5.0: Wireless streaming is stable and lets users pair phones or players without a cable for convenient audio sources.
• AUX and BT inputs: Dual input options provide flexible connectivity so users can switch between wired and wireless sources quickly.
• 2.1 channel output: Dedicated left, right and subwoofer outputs let listeners create a proper stereo plus low-frequency channel for fuller sound.
• Adjustable controls: Frequency, volume, treble and bass adjustments allow tuning to room acoustics and speaker response for better sound balance.
• Built-in protections: Anti reverse connection, overheat, overcurrent and short circuit safeguards help protect connected speakers and the board.
• Wide voltage range: DC 12-24V operation gives flexibility for different power supplies and portable or fixed installations.

Who It's For

This board is aimed at DIY audio enthusiasts, makers building small powered speaker systems, and anyone upgrading an existing 2.1 setup who needs Bluetooth plus AUX connectivity. Its compact PCB form and adjustable tone controls make it a good match for custom subwoofer cabinets and multi-speaker arrangements up to moderate power.

It is less suitable for users who require built-in enclosure, pre-mounted connectors, or a finished consumer product; those wanting a plug-and-play powered speaker with cosmetic housing should look for a complete amplifier chassis instead.

Pros & Cons

Pros

• Bluetooth 5.0 and AUX inputs offer flexible source options for modern devices and legacy players.
• 2.1 channel outputs and tone controls make it straightforward to tune a system with a dedicated subwoofer.
• Protection features reduce the risk of damage from wiring mistakes or thermal issues during use.
• Operates on DC 12-24V so it can be used with a variety of power supplies in bench or mobile setups.

Cons

• As a bare PCB it requires assembly and mounting hardware; buyers should be comfortable with basic wiring and installation.
• Specification language suggests a wide power range but exact continuous wattage per channel is not listed, so high-end audiophile ambitions may be limited.

Specifications

Item Type	Power Amplifier Board
Channels	2.1 channel (left, right, subwoofer)
Working Voltage	DC 12-24V
Bluetooth Version	BT 5.0
Input Sensitivity	500mV
Sound Input	Bluetooth + AUX

Our Verdict

The ZKMT21 100W Bluetooth amplifier board is a practical, value-oriented choice for DIYers who need a compact 2.1 amplifier with reliable wireless streaming and tone controls. Its protection features and broad voltage compatibility make it a sensible component for custom speaker projects, offering strong real-world utility without the frills of a finished consumer amp.

Frequently Asked Questions

Does this board support wired and wireless inputs?
Yes, it accepts both Bluetooth 5.0 and AUX inputs so you can use wireless devices or a wired source.

What power supply is required?
The board runs from DC 12-24V; choose a supply that matches your speaker power needs and provides adequate current.

Can I adjust the bass and treble?
Yes, the board includes adjustable frequency, volume, treble and bass controls for system tuning.