BOSS Audio MGR350B
#6 in Gauge-holeFull review
A step up from the MGR300B for a gauge-hole install, with better water resistance, a weather band and a subwoofer output.
Amazon $178.94$178.94
The BOSS Audio MGR350B and the Kenwood KMR-M300BT are evenly matched, rated 2.7 and 2.6. The Kenwood KMR-M300BT wins on features. The BOSS Audio MGR350B costs $120.06 less ($178.94 vs $299).
Prices were last checked November 9, 2026. Product prices and availability are accurate as of that date and are subject to change; the price and availability shown on Amazon or the retailer's site at the time of purchase apply. As an Amazon Associate we earn from qualifying purchases.
Kenwood KMR-M300BT
#7 in Gauge-holeFull review
A full-featured gauge-hole stereo for a small boat or powersports dash. Spend more on the eXcelon KMR-XM500 only if you want its 5 V pre-outs and longer warranty.
Amazon $299$299
Which should you buy?
- Choose the Kenwood KMR-M300BT for features (SiriusXM-ready, weather band, Bluetooth, USB playback vs weather band, Bluetooth, USB playback).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every gauge-hole marine stereo; a clear win is highlighted. How we rank explains each one.
| Factor weight | BOSS Audio MGR350B | Kenwood KMR-M300BT |
|---|---|---|
| Overall rating | 2.7/5 | 2.6/5 |
| Amplifier power 20% | 50 RMS power at 4 ohm not published (neutral score used) | 19 19 W RMS x 4 at 4 ohm |
| Zones 15% | 0 single zone | 0 single zone |
| Pre-amp outputs 10% | 29 3 RCA output sets | 29 3 RCA output sets at 2 V |
| Features 25% | 35 weather band, Bluetooth, USB playback | 50 SiriusXM-ready, weather band, Bluetooth, USB playback |
| Water rating 10% | 70 IPX6 front | 70 IP66 front |
| Display 10% | 50 display not published (neutral score used) | 58 2.7 in color |
| Warranty 10% | 0 warranty not published, scored as none | 0 1-year warranty |
Specifications
| BOSS Audio MGR350B | Kenwood KMR-M300BT | |
|---|---|---|
| Audio | ||
| Amplifier power (RMS, 4 ohm) | - | 19 W x 4 RMS |
| Zones | 1 | 1 |
| RCA output sets | 3 | 3 at 2 V |
| Sources and control | ||
| Bluetooth | Yes | Yes |
| USB playback | Yes | Yes |
| Phone app | No | No |
| SiriusXM-ready | No | Yes |
| NMEA 2000 | No | No |
| Wi-Fi or AirPlay 2 | No | No |
| Weather band | Yes | Yes |
| DAB+ | No | No |
| CD player | No | No |
| Camera input | No | Yes |
| Build | ||
| Mount | Gauge hole | Gauge hole |
| Front water rating | IPX6 | IP66 |
| Display | - | 2.7 in color |
| Warranty | - | 1 year |