Both of Boss Audio's wake tower speakers clamp onto the same general range of tower pipe, and both are 4" two-way designs. The difference that actually matters is whether the amplifier lives inside the speaker or needs to be wired in separately, and picking the wrong one for your situation means redoing a wiring plan you'd already committed to.
Key Takeaways
- The MRWT40 ($239.99/pair) is a passive speaker, it needs a separate amplifier to produce sound, the same as any standard speaker.
- The BM40AMPBT ($449.99) has a Class D amplifier built directly into the enclosure, no separate amp required, plus an included in-line remote with illuminated controls.
- The MRWT40 fits 1.5" to 2" tower pipes; the BM40AMPBT fits a slightly wider 1" to 2" range, confirm your specific tower's pipe diameter against each listing before choosing.
- The BM40AMPBT costs nearly twice as much, and that premium buys the built-in amp and remote, not a dramatically different speaker.
- Both carry a 94dB sensitivity rating and similar frequency response, the core driver performance is comparable between the two.
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MRWT40: The Passive Option
At $239.99 for the pair, the MRWT40 is a standard passive 2-way speaker in a marinized, tower-mount enclosure, 4" woofer, 1" dome tweeter, 200W RMS / 400W peak total. It needs a separate amplifier wired in to actually produce sound, the same requirement as essentially any standard marine speaker. If you already have amplification in place, whether from Boss Audio's own Elite line or another brand, this is the lower-cost way to add tower-mounted sound to an existing system.
BM40AMPBT: The Amp Comes With It
At $449.99, the BM40AMPBT builds a Class D amplifier directly into the speaker enclosure, 250W RMS / 500W peak, with no separate amp wiring required. It also includes an IPX5-rated in-line remote with illuminated soft-touch controls, a genuinely different installation experience than the MRWT40: run power and ground to the speaker itself, connect the remote, done. This is the more expensive option, but the premium buys a meaningfully simpler install for someone who doesn't already have amplification in place or doesn't want to run a separate amp wire to the tower.
Weight and Mounting Stress on the Tower
A tower-mounted speaker adds real weight at height, and the amplified BM40AMPBT's built-in electronics make it the heavier of the two options per side. On a smaller or older tower structure, confirm the clamp mount is rated for the actual combined weight at that mounting height, vibration and stress at a high mounting point are a different consideration than the same weight mounted low on a hull or dash.
The Pipe-Diameter Detail Worth Checking Twice
The two speakers clamp to slightly different pipe ranges, the MRWT40 fits 1.5" to 2", the BM40AMPBT fits 1" to 2". If your tower's actual pipe diameter is at the narrower end of that range, confirm against the specific product you're choosing rather than assuming both options fit identically, since the MRWT40's range starts at a larger minimum diameter than the BM40AMPBT's.
Frequency Response: A Small but Real Difference
The BM40AMPBT's frequency response (45Hz-20kHz) extends meaningfully lower than the MRWT40's (130Hz-20kHz), a real difference beyond just the built-in amp. That lower extension means the BM40AMPBT alone handles more of the midbass range without relying as heavily on a separate subwoofer to fill in that gap, worth factoring in if your tower build doesn't include a dedicated sub and you're counting on the tower speakers to cover more of the frequency spectrum on their own.
How to Actually Decide Between Them
If you already have an amplifier running power to speakers elsewhere on the boat and just need tower-mounted drivers added to that existing circuit, the MRWT40 is the more cost-effective choice, you're not paying for amplification you don't need. If you're adding tower sound to a boat with no existing amp in that area, or want the simplest possible installation without running a separate amp wire up to the tower, the BM40AMPBT's built-in amp and included remote justify the higher price.
What the Extra $210 Actually Buys
It's worth being specific about where the BM40AMPBT's higher price actually goes, since "it has an amp built in" undersells what's included. You're getting the amplifier itself (otherwise a separate $240-$480 purchase from Boss Audio's own Elite line), the wiring and mounting work already done inside one enclosure, and the IPX5-rated illuminated remote, a control accessory that doesn't have a direct equivalent bundled with the passive MRWT40 at all. Priced as separate pieces, amp plus passive speaker plus a remote, the bundled BM40AMPBT is a reasonable value for someone who'd be buying all three pieces anyway.
Honest Cons
The BM40AMPBT's built-in amp means less flexibility to upgrade power later, unlike a passive speaker paired with a separate, swappable amp, the amplifier here is fixed to the enclosure.
The MRWT40 requires a separate amp purchase if you don't already have one, factor that real additional cost in before assuming it's the cheaper overall option for a from-scratch build.
This is a new product line to our coverage, published specs are reported accurately, but we don't yet have the extended installation history we've built with other brands' tower speaker lines.
Frequently Asked Questions
Do I need a separate amp for the BM40AMPBT?
No, that's the entire point of this model, the amplifier is built into the speaker enclosure.
Can I mix one MRWT40 pair and one BM40AMPBT pair on the same boat?
There's no technical reason you couldn't run both in different zones, though matching them to appropriate, separate amplification (or none, for the amplified pair) is still required for each.
What tower pipe size do these actually fit?
MRWT40: 1.5" to 2". BM40AMPBT: 1" to 2". Measure your actual tower pipe before ordering either, rather than assuming a general "wake tower speaker" category fits any diameter.
Is the BM40AMPBT's remote required to use the speakers?
It's included for volume and source control convenience; check the specific listing to confirm whether basic operation is possible without it if that's a concern for your build.
Does either speaker include lighting?
Based on the specifications we reviewed, neither the MRWT40 nor the BM40AMPBT is listed with integrated RGB or LED lighting, unlike Boss Audio's dedicated RGB speaker line, which does include it.
Bottom Line
Same general tower-mount concept, genuinely different installation requirements. The MRWT40 is the lower-cost choice if you already have an amp in place; the BM40AMPBT's built-in amplification and included remote are worth the premium if you're starting from nothing on the tower specifically.