BOSS Audio ASK904B.64 Marine 6.5in Speakers and 4-Channel Amp

In this review of the BOSS Audio ASK904B.64 combo, the bottom line is simple: this kit is for buyers who want a compact, weather-resistant marine audio solution that can run without a head unit and deliver loud, full-range sound on a budget. The package pairs a 4-channel MC900B amplifier with two pairs of 6.5in MR6W speakers and adds Bluetooth streaming, a USB charging option and a waterproof remote pouch-making it a practical pick for boats, UTVs and open-air vehicles where ease of installation and wireless playback matter most.

Key Features

• 500 Watts Max Power: The MC900B provides up to 500 W max across four channels so small craft and off-road rigs can get high output when needed.
• Bluetooth Ready: Built-in Bluetooth and an inline multifunction remote let users stream from phones and apps like Spotify without a separate head unit.
• Full Range Speakers: The included MR6W 6.5in speakers are full-range with polypropylene cones and rubber surrounds to reproduce a wide frequency range with decent durability.
• Weather Resistant Design: Weatherproof connectors and components are intended to tolerate light marine conditions and occasional spray.
• USB Charging and Aux: A USB charging/data adapter and auxiliary input give practical, modern connectivity for phones and MP3 players.
• Compact Amp Form Factor: The amplifier measures approximately 7.8 x 3.8 x 1.8 in and weighs about 2.9 lbs for flexible mounting in tight spaces.

Who It's For

This kit suits boat owners, anglers, and outdoors enthusiasts who want loud, easy-to-install sound without adding an in-dash head unit. If you need Bluetooth streaming, USB charging and a compact 4-channel amp that can drive a pair of full-range 6.5in speakers, this package covers those bases and keeps wiring straightforward.

Those seeking audiophile-grade fidelity, extremely rugged military-spec marine gear, or long-term reliability assurances should consider higher-end sealed marine systems or separate premium components. Some buyers also reported mixed long-term reliability, so installers who expect daily heavy use should weigh professional installation and protection options.

Pros & Cons

Pros

• Strong perceived output for the size, making it easy to hear over wind and engine noise.
• Bluetooth streaming and inline remote remove the need for a head unit for many setups.
• Weather-resistant connectors and rubber-surround speakers improve performance in damp conditions.
• Good value for the combination of amp plus two pairs of speakers and charging convenience.

Cons

• Some users reported inconsistent long-term reliability, so durability may vary between units.
• Not built as a premium audiophile kit; sound quality is good for casual listening but not high-end critical listening.

Specifications

Amplifier Power	500 W max x 4 @ 4-Ohm
Amp Topology	Class A/B full range
Amp Dimensions	7.8 x 3.8 x 1.8 in
Speaker Size	6.5 in full range (pair)
Speaker Power	180 W per pair
Speaker Frequency	80 Hz to 20 kHz
Speaker Sensitivity	89 dB

Our Verdict

The ASK904B.64 combo is a practical, budget-friendly marine audio kit that delivers surprising volume and easy Bluetooth playback without a head unit, making it a smart choice for casual boaters and off-road users. It offers clear value when installed correctly, but buyers who need long-term heavy-duty reliability or audiophile sound should consider higher-tier marine components.

Frequently Asked Questions

Can I use this without a head unit?
Yes. The amplifier supports Bluetooth streaming and a multifunction remote so you can power the amp and stream music directly from a phone.

Are the speakers waterproof?
The speakers are weather resistant with polypropylene cones and rubber surrounds; they are designed for light marine exposure but not full submersion.

Does the amp support charging a phone?
Yes. The package includes a USB charging option so you can charge and play a USB-connected device while using the system.