The Rockford Fosgate PMX-3 is the upgraded version of the PMX-2, one of the most popular marine-grade, square style radios. The PMX-2 was one of the first compact, marine grade head units and it was the perfect option for boats, UTVs, RVs, or anything else needed to withstand the elements. The Rockford Fosgate PMX-3 has virtually everything you would want and need from a compact, marine grade head unit. The PMX-3 has Bluetooth, an AM/FM/WB tuner, a USB Port, Auxiliary, Pandora Control, and 2 zone outputs. The unit has a full-color TFT display that measures 2.7" diagonally. The features that differentiate the PMX-3 from the PMX-2 is the camera input with the trigger wire and it is SiriusXM ready. For pre-amp outputs, the PMX-3 has two zone outputs with a front zone and selectable Rear/Subwoofer zone where you select via the menu on the radio whether the second zone will be a full-range zone or subwoofer(s).

Like the Rockford Fosgate PMX-3, the Wet Sounds WS-MC-20 is the upgraded version of their square style head unit, the WS-MC-2. The Wet Sounds WS-MC-20 also comes with Bluetooth built in, an AM/FM/WB tuner, AUX input, and USB. The WS-MC-20 is also SiriusXM ready and it has a camera input with the trigger wire. The display on the WS-MC-20 is slightly larger, measuring 3" instead of 2.7" and the WS-MC-20 is NMEA 2000 ready if you use your boat in saltwater. One of the big differences between the PMX-3 and the WS-MC-20 is the number of zones. The WS-MC-20 essentially has 3 zones. You have front and rear for the front zone and you can configure the other zone to be either "Zone 2" or a subwoofer. This lets you fade the front zone between front and rear and you can control Zone 2 or the subwoofer separately, effectively giving you 3 zone control.

With the WS-MC-20, you get front and rear off of zone 1 and you can select whether you want zone 2 to be a full-range zone for speakers or just for subwoofers. The big difference is the low pass filter when it is set to ssubwoofer mode. On the PMX-3, you only have zone 1, and for zone 2, you have the same option for full range zone 2 or subwoofer. The big difference here is the ability to fade for Zone 1. If you have a boat with speaker in the bow, at the helm, and at the back, you can set the bow speakers to "Front" and the helm and rear speakers to "Rear". You also have the ability to control your subwoofer separately. Another option would be to set your hull speakers to the front of Zone 1, your tower speakers to the rear of Zone 1, and then set Zone 2 as your subwoofer zone. This would allow you to fade between your hull and tower speakers and also give you subwoofer control. These situations might be ideal if you are in the water swimming and you want music from your tower speakers, but you don't want to blast your family that is still in the boat. With the Rockford Fosgate PMX-3, you can't fade between front and rear on Zone 1. Zone 1 would be all your speakers and Zone 2 would be your subwoofer.

The Wet Sounds WS-MC-20 is NMEA 2000 ready and the Rockford Fosgate PMX-3 is not. This typically applies to salwater applications where your boat may have a NMEA 2000 network. The NMEA 2000 Network allows you to connect multiple, multi-function devices to the network and use the functionality of any NMEA 2000 device on any NMEA 2000 compatible display. This means, you could control the WS-MC-20 on the MFD device you have at the helm without having to actually adjust volume or change songs on the head unit itself. This is typically stuff for bigger boats with navigation, fish finders, etc.

The Rockford Fosgate PMX-3 is Built for iPhone and you can plug your iPhone into the USB port and control everything on your phone itself. The Built for iPhone badge means that the PMX-3 has an Apple certified chip inside to make sure it works with the current versions of the iPhone. The Wet Sounds WS-MC-20 does not have the "Built for iPhone" chip, but it will still support both the connection and charging of Apple devices. If you have a current phone, this doesn't really mean much and this only pertains to the USB connection. Both devices will charge your iPhone. Both devices will connect to your iPhone. The Rockford PMX-3 has the certification and they paid Apple money to make it say, "Made for iPhone," while Wet Sounds simply verified that it works with the iPhone without paying the money for the certification and the right to say, "Made for iPhone." Since both units are Bluetooth, this isn't THAT big of a deal. Regardless, you could still charge your phone via USB but play your music via Bluetooth on either device without any issues.

The display on the WS-MC-20 is slightly larger than the display on the PMX-3. They are both full-color, TFT displays. The display on the PMX-3 is 2.7" and the display on the WS-MC-20 is 3".

The Rockford Fosgate PMX-3 has Pandora control. Once your account has been synced and connected, you can control your Pandora stations on the PMX-3 itself instead of needing to use your phone. Is this important? That's hard to say. Usually, the interface on your phone is much faster and easier than using the small screen on the PMX-3 itself. But, if you are a big, "Hands-free" person, you can control your Pandora on your radio without picking up your phone.

The best head unit will depend on your boat and how you use it. If you have a NMEA 2000 network on your boat, the WS-MC-20 is definitely the way to go. Outside of the NMEA 2000 connection, the second most important thing is the number of zones. The Wet Sounds WS-MC-20 allows for more control of your music levels in different areas of your boat. The front and rear, 4 channel outputs for Zone 1 are the big difference maker versus simply having 2 channel output for Zone 1 on the PMX-3. In our opinion, the Made for iPhone certification isn't that big of a deal. The WS-MC-20 still works with the USB port and it will both connect and charge most iPhones. These days, most people are using Bluetooth for that connection, or if you are a true audiophile, you have Hi-Res tracks on a thumb drive. Either way, the USB connection to the iPhone isn't that big of a deal because the USB port will charge the phone. The Pandora control is a non-factor. It's way easier and faster to control Pandora on your phone. In our opionion, the WS-MC-20 is a better head unit than the PMX-3 because it has better zone control, it has a slightly larger screen, and it is NMEA 2000 ready.