Douk Audio M4 Bluetooth 4-Channel Amp 50W Review

The Douk Audio M4 is a four-channel digital amplifier priced at $79.99, designed for stereo or four-channel use at home and on the desktop. The feature that sets it apart is its flexible channel routing rather than raw audiophile specs.

The amp gives you four groups of speaker sockets, each with independent volume control, with a maximum output of 50W x 4 into 4Ω loads powered by the included 24V/4.5A supply. Speaker impedance can be 4-8Ω. One group of stereo RCA inputs, labelled CH3 and CH4, can be switched between input and output duty: as outputs, the four speaker sockets can drive two pairs of speakers or feed another M4 amplifier, so multiple amplifiers and speakers can be daisy-chained and one audio signal shared across several rooms. As inputs, one input corresponds to one output, meaning two groups of stereo audio (or four mono) can be fed in simultaneously.

Sources cover wired stereo RCA, Bluetooth 5.0 with a high-gain antenna, and U-disk playback supporting MP3, WMA, APE, FLAC and WAV up to 32GB. The maker notes the U-disk input takes priority over Bluetooth, so the drive should be removed to use the wireless input. Measured specs are THD of 0.05% at 1kHz and 1W, SNR of at least 98dB, an input sensitivity of 0.775V and a 20Hz-20KHz (±3dB) frequency response. The case is CNC-machined, anodized aluminium measuring 128 x 134 x 33mm and weighing 533g, and the small-signal and large-signal circuits are laid out separately for protection.

Specifications

How it compares

At the same $79.99, the Douk Audio M1 PRO Bluetooth Amplifier 160W review swaps the M4's four outputs for two channels: a TDA7498E rated 160W x 2 into 4 ohms, with Bluetooth 5.0, RCA and U-disk inputs and a low-frequency output for an active subwoofer. Take the M1 PRO for one stereo pair plus a sub; take the M4 if you need four independent speaker outputs, each with its own volume control, or a spare stereo RCA pair to chain a second M4.

For surround rather than rooms, the Nobsound M5.1 5.1 Channel Home Theatre Amp review ($169.99) lists front, surround, center and bass channels at 50W each, plus optical and coaxial inputs, for $90.00 more. For more power across four channels, the Douk Audio G7 2.0/4.0 Channel Digital Amplifier review ($299.99, $220.00 more) lists 300W x 2 or 150W x 4 at 4 ohms from a built-in 48V/10A supply, two sets of switchable or simultaneous speaker outputs and balanced inputs, but no Bluetooth input on its page and a 275 x 190 x 78mm, 3.34kg body. The M4 suits a small multi-room or four-speaker setup where Bluetooth, a compact case and per-channel volume matter more than power.

Shipping, returns and warranty

• Shipping: Douk Audio's current shipping page says orders are generally processed no later than the next business day and arrive in 2-8 business days, with duties, taxes and customs fees included in the checkout price unless noted otherwise.
• Older shipping terms are still online: airmail at 10-25 days for parcels under 2 kg, DHL, UPS or FedEx at 5-8 days above that, and a line saying the store is not responsible for import duties. Check the delivery estimate and any duties at checkout.
• Returns: ask within 30 days of delivery and wait for approval before sending anything; an approved return has to ship within 7 days. Items need all packaging and accessories and no excessive wear, or the store can refuse them or refund part of the price. Refunds go to the original payment method after inspection.
• Not refunded: original and expedited shipping, duties, taxes and customs charges, unless the law requires it or the store made the error. The return page does not say who pays return postage, and the older refund page excludes mistaken orders and change-of-mind returns from free after-sale service.
• Warranty: 24 months from purchase for manufacturing defects, with free repair, a replacement unit and free shipping both ways for covered repairs. Drops, liquid, DIY repairs, lightning, extreme temperatures and misuse are excluded (partial fees may apply), and damage from weak packing on the way back may not be covered. The older refund page still says 1 year.
• Seller: the site is run by Shenzhen Anba Technology Co., Ltd (Shenzhen, China) and HONGKONG LONGSHENG Import and Export Trading Co., Limited (Hong Kong); support is by email at [email protected]. These terms cover orders placed on doukaudio.com; other sellers apply their own.

For this product, the page lists US, UK, EU, AU and Other under 'Shipping to' and shows Free Shipping, 2-8 Days Arrival, 30-Day Return and 2-Year Warranty badges near the price.