Most Boss Audio kits pair a stereo with speakers. The ASK904B.64 skips the stereo entirely, a real 4-channel amplifier with its own Bluetooth control, wired directly to two pairs of speakers, built specifically for a boat, UTV, or golf cart with no room for a dedicated head unit.
Key Takeaways
- The ASK904B.64 ($449.99) bundles the MC900B Bluetooth amplifier with a multi-function controller, two pairs of 6.5" MR6W speakers, a waterproof pouch, and a USB/Aux extension cable.
- This is a genuinely different kit category than Boss Audio's stereo-plus-speaker kits, there's no gauge-hole receiver here at all, the amplifier itself handles Bluetooth pairing and control.
- Four speakers from one kit means bow-and-stern or front-and-rear coverage without buying a second speaker pair separately.
- The included waterproof pouch is specifically for protecting a connected phone or the amplifier's control module from spray, a detail worth understanding before assuming it's just packaging.
- At $449.99, this sits above the simpler stereo-plus-single-speaker-pair kits, reflecting the added amp capability and second speaker pair, not just a price increase for the same scope.
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Why Skip the Receiver Entirely
Not every build has a logical place to mount a gauge-style or flush receiver, a small boat's console, a UTV dash, a golf cart with no obvious cutout location. The ASK904B.64 solves that by putting Bluetooth control directly into the amplifier itself via the MC900B's multi-function controller, meaning there's no separate head unit to find mounting space for at all. Control happens from a paired phone, with the amp as the only electronics module that actually needs a mounting location.
Four Speakers From One Kit
Two pairs of MR6W 6.5" speakers means genuine bow-and-stern or front-and-rear coverage from a single purchase, rather than buying a basic 2-speaker kit and then sourcing a second matching pair separately later. If your build genuinely needs four speakers, this kit's per-speaker cost works out favorably compared to buying two separate 2-speaker kits, since you're only paying for one amplifier and one set of accessories rather than two.
The Waterproof Pouch, Explained
The included waterproof pouch is for protecting the connected control device (typically a phone) or the amp's exposed control module from direct spray or rain, not a generic accessory bag. On a boat or UTV where the amp's control point is mounted somewhere genuinely exposed, this is a real, functional inclusion, not packaging filler, worth factoring into your overall judgment of what $449.99 actually buys versus assembling similar components separately.
Where the Four Speakers Actually Go
A natural split for the two speaker pairs is bow and stern on a boat, or front and rear on a UTV or golf cart, each pair wired to its own pair of the amp's four channels. This isn't a dedicated multi-zone system the way a Kicker build with a zone-capable receiver offers, both pairs share the same volume and source control from the single amp, but it does mean sound actually reaches both ends of the vehicle rather than concentrating from one location.
Comparing This to Buying the Pieces Separately
A standalone MPD380.4 4-channel amp from Boss Audio's own Elite line runs $364.99 on its own, before adding speakers. Two pairs of comparable 6.5" speakers from the standalone lineup would add real cost on top of that. The ASK904B.64's $449.99 bundled price is a genuine value against assembling the same rough scope from separate standalone purchases, the tradeoff is the MC900B's Bluetooth-amp combo unit specifically, rather than pairing the Elite-series amp with speakers of your own separate choosing.
Where This Fits Among Boss Audio's Other Kits
This is a genuinely different product category from the stereo-plus-speaker kits, those bundle a receiver with built-in power and one speaker pair; this bundles a dedicated amplifier (with its own Bluetooth control) and two speaker pairs, no receiver anywhere in the equation. If you're comparing kits across the lineup, the real question isn't which one is "better," it's whether you want a traditional receiver with a display and radio tuner, or a Bluetooth-first control model with real external amplification and double the speaker count.
Honest Cons
No receiver means no radio tuner or physical display, this is a Bluetooth-and-aux-only control model, if you want AM/FM radio as a source, this isn't the right product.
The MC900B amplifier is a fixed unit paired specifically with this kit, you're not selecting your own amp and speaker combination the way a fully modular build allows.
This is a new product to our coverage, published specs are reported accurately, but we don't yet have the installation history we've built with other, longer-covered product lines.
Frequently Asked Questions
Can I add a receiver to this system later?
The MC900B amp likely accepts RCA or auxiliary input in addition to Bluetooth, confirm the specific input options on the current listing if adding a receiver later is part of your plan.
Do I need all four speakers, or can I run just one pair?
The kit is designed and priced for all four together; running just one pair is possible but means the second pair goes unused rather than being a cost savings.
What's the waterproof pouch actually for?
Protecting a connected phone or the amp's control module from spray, not general accessory storage.
How does this compare to a standalone amp plus speakers bought separately?
The bundled price is generally favorable versus assembling the same scope piece by piece, the tradeoff is using the specific MC900B amp rather than choosing your own from Boss Audio's standalone Elite line.
Is this a good fit for a boat that already has a working receiver installed?
Not really, the value here is specifically for builds with no receiver at all; if you already have one working, a standalone amp and speaker purchase that integrates with your existing receiver makes more sense than this bundle.
Bottom Line
The ASK904B.64 answers a specific problem, real amplification and four speakers with no room or need for a separate head unit, at a price that beats assembling the same scope from standalone components. It's the right fit for a Bluetooth-only build with no existing receiver, not for anyone who wants a radio tuner, a fully custom component selection, or already has a working head unit in place.