Marine Subwoofers by Product Type
None. The two words are synonymous when it comes to marine subwoofers. It means that the subwoofer does not need to be mounted in an enclosure. From a marine perspective, it means you can install the subwoofer directly into the hull of the boat without having to worry about the proper air space. When you see a subwoofer that is designed for an enclosure, this means that the subwoofer needs to be in a controlled environment with a fixed amount of air space to operate properly.
Whether or not you need to put your marine subwoofer(s) in a box depends on the type of subwoofer. Most marine subwoofers are designed for infinite baffle applications. If you have an infinite baffle subwoofer, it does not need to be in a box. If you have a subwoofer that is designed for an enclosure, it does need to be installed in an enclosure. Most marine subwoofers are designed for free air applications. The subwoofers that are designed for enclosures usally have a free air version available. Examples of this are the Kicker marine subwoofers and the JL Audio M6 marine subwoofers. Both product lines have both free air and enclosure models available.
Absolutely. It is actually very popular. You can put a loaded subwoofer enclosure that was built for a car and put it on your boat as long as it isn't going to get wet or exposed to UV light. Many people will put a car subwoofer enclosure in the dead space under a seat, or you can put them in the footwell area by the driver. Since car subwoofer enclosures are made of wood, if they get wet, they can rot and get pretty nasty, but if it lasts you 3-5 years, you might not care. You also want to make sure that the subwoofer itself is not exposed to UV light. Car subwoofers will not last in the sun's damaging rays like a marine subwoofer will. They don't use the special materials and the cost associated with those materials because in a car environment, it doesn't matter. If you can keep your subwoofer dry and out of the sun, you can save some money by opting to go with a car subwoofer enclosure for your boat.
Some marine subwoofers come with speakers grilles and others do not. All of the Rockford Fosgate and JL Audio subwoofers come with grilles. The Wet Sounds and Kicker marine subwoofers do not include grilles. We do recommend protecting your subwoofer with a grille so you will need to puchase one separately on our marine subwoofer grilles page. Kicker offers their marine subwoofer grilles in both charcoal and white and they include RGB LEDs. Wet Sounds has subwoofer grilles to match all of their speaker grille options.
Yes. You need to power a subwoofer with an amplifier. Your stereo by itself does not have enough output to adequately power a subwoofer.
In most cases, we recommend you power your marine subwoofer with an monoblock marine amplifier or a 5 channel marine amplifier from the same manufacturer. If you have a JL Audio marine subwoofer, it makes sense to select a JL Audio marine amplifier. JL builds their subwoofer amplifiers to work with their subwoofers. The same thing holds true for all of the other brands including Rockford Fosgate, Kicker, Wet Sounds, Memphis, Fusion, etc. The reason we recommend a monoblock or a 5 channel amplifier is for the signal processing. The monoblock and the subwoofer channel of most 5 channel amplifiers have a frequency response to match a subwoofer, usually only going as high as 500Hz. Alos, these amplifiers are designed to power subwoofers and many are 1 ohm stable to maximize the power output. If an amplifier is 1 ohm stable you have more options with subwoofer voice coils and it allows you to add more subwoofers. If you have single 4 ohm marine subwoofers, a 1 ohm stable amplifier will allow you to wire 4 subwoofers in parallel to a 1 ohm load. If the amplifier is only 2 ohm stable, you could still get creative with your wiring, but you are also wiring those 4 subwoofers and getting half the amount of power output, assuming there aren't any power supply or circuitry issues impacting Ohm's law.
Whether or not you need a bass knob for your marine subwoofer will depend on your head unit and your personal preferences. The bass levels can vary drastically from one song to the next, regardless of what type of music you listen to. Of course this is true with hip-hop and electronic music, but even with country music too. For example, Alan Jackson songs have more bass than most other country songs (we are not calling this new "Country" music, country music btw). Many marine marine head units have a subwoofer pre-out and subwoofer control. However, many of these source units do not have buttons on the front that allow you to quickly adjust the subwoofer level. Instead, you have to hit a couple of buttons to get to the subwoofer level screen, and then you can change the subwoofer level there. Some head units like the Rockford Fosgate PMX-2 and PMX-3 have buttons on the face of the head unit for fast and easy subwoofer level adjustment. If you don't have specific, subwoofer level adjustment buttons on the front of your head unit, we recommend adding a bass knob. Instead of fumbling through different screens and modes on your head unit, you can just turn the knob up or down to adjust the bass level for that song. If your head unit does not have a subwoofer pre-out or subwoofer level control, we definitely recommend adding a bass knob because the bass levels are different from one song to the next. It is nice when you have the ability to quickly and easily turn the bass up or down.
The main reason you would choose an 8" marine subwoofer is because you don't have the room to fit a 10" marine subwoofer. On a boat or in a UTV, bass is much different than in a car because it is an open air environment. You don't have a roof, door, windows or a trunk to boost those low frequencies as they bounce off surfaces and each other. If you want bass in your boat, you want the largest subwoofers you can get. If you can afford and fit a 10", get the 10" subwoofer instead of an 8". If you can afford and fit a 12", get the 12".
10" marine subwoofers are the most popular size for boats and other outdoor vehicles. Virtually all of the companies that make marine speakers, make a 10" subwoofer to match and go along with the speakers. When you compare the number of 8" and 12" models, you see that there are far more 10 inch options than the other two. Many boats do not have enough room to fit a 12" subwoofer, and a 10" is better than an 8", so the 10" wins primarily because it fits. Most 10" subwoofers are designed for infinite baffle use but there are several options for enclosures. Be sure to make sure you are getting the right type of subowofer for your application.
When comparing bass output in a boat versus a car, the output is completely different becuase of the open air environment. In order to get maximum bass output, you want a larger subwoofer. Since 12 inch marine subwoofers are bigger than 10 inch marine subwoofers, the 12's just hit harder, sound better, can handle more power, and give you better output. A 12" marine subwoofer can do everything a 10" marine subwoofer can do, but a 10" subwoofer can't do everything a 12" can. The one drawback of 12 inch marine subwoofers is the size and the limited number of options. Many boats don't have room to fit a 12" and as a result, there are significantly less 12" marine subwoofer models.