Can someone please recommend the correct battery to operate this product

I purchased a 24Vdc@10 amps power supply. A lithium battery supply from parts Express using 5 18650's cells is 21Vdc and would work just fine.

Will it be useful to install a crossover? or is it not necessary?

I have tree of these running Speakers and sub-woofers with no crossover.

does the main volume affect the sub volume or are they completely independent?

The sub volume is not completely independent . I guess it’s kinda like having a gain adjustment on a car stereo amp ..

What is the output wattage using a 12v input at 8 ohms?

12 watts or so. To get 50W you need 24V at about 3.5 amps at 4 ohms.

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Bluetooth Power Amplifier Board with Subwoofer 2.1 Channel 50W×2+100W, 12V-24V Audio Power Amplifier Module with Treble and Bass Control (ZK-MT21)

Product ID: 368986425

Details

Item dimensions L x W x H
4.37 x 4.05 x
Manufacturer
DAJUNGUO
Maximum Supply Voltage
24 volts
Minimum Supply Voltage
12
Voltage
20 volts

🔊50W×2+100W output power

🔋12-24V wide voltage input

🎚️Treble & bass adjustable controls

¥5359

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Sold byAmazon JapanDelivered byDesertcartCustomer service byDesertcartReturns14 days · 30 with PRO

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Description

🎧 Elevate your sound game—because your audio deserves to be as sharp as your style.

VERSATILE CONNECTIVITY - Seamlessly connect via Bluetooth, AUX, or USB—compatible with all your devices.
POWERHOUSE AUDIO OUTPUT - Delivers a robust 50W per channel plus a booming 100W subwoofer for immersive sound.
COMPACT PORTABLE DESIGN - Lightweight 130g module fits effortlessly into custom builds or portable party speakers.
RELIABLE SAFE OPERATION - Built-in protections guard against short-circuit, over-current, overheating, and reverse polarity.
CUSTOMIZABLE SOUND EXPERIENCE - Fine-tune your audio with dedicated treble and bass controls for perfect layering.

The ZK-MT21 Bluetooth Power Amplifier Board is a compact yet powerful 2.1 channel audio module delivering 50W×2 plus 100W subwoofer output. It supports a wide 12-24V input range and multiple inputs including Bluetooth, AUX, and USB. With adjustable treble and bass controls, plus comprehensive protection features, it ensures high-fidelity sound and reliable performance for custom audio projects and portable speaker builds.

Specifications

ASIN	B09HKB44JQ
Best Sellers Rank	#42,424 in Electronics ( See Top 100 in Electronics ) #240 in Audio Component Amplifiers
Brand Name	DAJUNGUO
Customer Reviews	4.4 4.4 out of 5 stars (452)
Included Components	amplifier board
Item Dimensions	4.37 x 4.05 x 1.02 inches
Item Weight	130 g
Manufacturer	DAJUNGUO
Maximum Supply Voltage	24 volts
Minimum Supply Voltage	12 volts_of_direct_current
Model	ZK-MT21
Mounting Type	Surface Mount
Number of Channels	2
Package Type Name	Hard Case
Part Number	ZK-MT21
Supply Current	5 A
UPC	194852390669
Unit Count	1 Count
Voltage	20 volts

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TrustScore 4.5 | 7,300+ reviews

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¥5359

Duties & taxes included

In stock

Sold byAmazon JapanDelivered byDesertcartCustomer service byDesertcartReturns14 days · 30 with PRO

Buyer Protection · Full refund if your order doesn't arrive as described.

Desertcart purchases this item on your behalf and handles shipping, customs, and support to Japan.

Secure transaction

Trustpilot

TrustScore 4.5 | 7,300+ reviews

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Very impressed with the quality and fast delivery. Will shop here again.

4 days ago

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Smooth transaction and product arrived in perfect condition.

3 weeks ago

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