Exterior Sound Systems

Speakers, bars & other ways to make some noise.

This article originally appeared in the August 2023 issue of THE SHOP magazine.

Customers love their toys. They love side-by-sides in the desert. They love Jeeps on mountain trails. They love motorcycles on open highways and hanging out with friends in the parking lot.

And what makes these experiences even better? A killer audio system, of course.

Everyone knows aftermarket stereos are a must for many automotive enthusiasts. But what if those drivers and riders want to share their tunes with the outside world?

To get loud outdoors, knowledgeable mobile electronics specialists turn to pro audio solutions including bullet tweeters, horn drivers and high efficiency speaker arrays—including technology being built into today’s portable and vehicle-mounted soundbars.


As pro audio components, outdoor solutions need a good power source, so the same best-practice principles found in related quality interior 12V installations still apply. To achieve clear, loud sound, you need a decent battery, a good alternator, quality amplification and reliable wiring.

In an outdoor environment, care needs to be taken to protect electrical connections. Additionally, certain outdoor vehicles (aside from Jeeps) tend to have smaller alternators, so efficient amplification and loudspeakers can make all the difference.

Shops can offer an all-out custom installation or something premade to fit any budget.

Custom loud pro audio-based sound systems have been popular in Latin America for years, and KICKER is entering the U.S. market. Understanding that these loudspeakers will be pushed to the limits, the company has created a specialty bullet tweeter that is rebuildable in case it is damaged.

The hip-to-be-square-shaped ST Series midrange speakers include pressed pulp cones, treated cloth surrounds and heavy ferrite magnets with high sensitivity. The KICKER loudspeakers come in 7- and 9-inch sizes in both 4- and 8-ohm versions.

Exterior Sound Systems | THE SHOP
KICKER ST Series speakers

The availability of different impedances (ohms) allows installers to add drivers to safely get the most out of the amplifier. If a customer wants to get loud on the tweeter side with hair-raising vocal clarity at a distance, the bullet design is probably the best bet for outdoor applications.

“You want clean, clear vocals—no matter how loud the bass is,” KICKER says. “The ST Series Bullet Tweeters are the answer. Perfect for competition-level SPL systems, these tweeters deliver smooth, loud detail to cut through bass like a knife through butter. Install them flush or use the included trim bezel to surface-mount almost anywhere.”

Field-replaceable rebuild kits are also available, and for the customer who wants to go all out, a system can be designed around these midrange and bullet tweeters in a multitude of vehicles including side-by-sides and motorcycles.

Getting subbass to complement pro audio is similar to getting it in a car, but with a different box design. There will always be limits on the amount of space available, but usually a reasonable subwoofer enclosure can be fitted to the vehicle without taking up too much room.


For many customers, the simplicity of an all-in-one solution makes a lot of sense. JBL took its time designing its Rallybar series of outdoor vehicle loudspeakers.

There are three sizes, and the big guy is the new Rallybar XL. The largest offering expands on the original UB4100, now with the addition of a built-in 300W amplifier. The three models support Hi-Res audio and offer 1-inch tweeters and an array of 3-inch mid-range drivers and large 3-by-7.3-inch racetrack passive radiators to deliver the bass.

Exterior Sound Systems | THE SHOP
JBL took its time designing its Rallybar series of outdoor vehicle loudspeakers.

The passive radiator layout actually delivers more surface area than a 10-inch subwoofer. The Rallybar XL features 10 speakers and four radiators. The regular-sized Rallybar supports a 150W amplifier with six speakers and two passive radiators. All three models are equipped with a HARMAN-tuned DSP, USB play, aux-in and out and Bluetooth, with the ability to sync to an unlimited number of additional Rallybars.

Both the Rallybar XL and Rallybar feature seven-way customizable party lighting along with a map light function for in-vehicle use. The innovative design is rugged enough for any adventure, featuring an IP66 rating so it’s safe to spray them down after a long day in the mud.

To make installations easier, JBL designed a unique mounting bracket that swivels 360 degrees coupled to a variable clamp so it can mount to any rollbar or wakeboard tower, no matter the angle or diameter.

“The Rallybar family drafts on the success of the original JBL UB4100, but now we have even more bass, more sound pressure levels, Hi-Res audio and party lighting with flexibility of installation,” says Jeffery Fay, Harman VP. “We also really dig the dome light feature, so you can still enjoy the party after the sun sets, or at least be able to locate all your controls before you set off when it’s dark.”

Meanwhile, if a customer wants a specific side-by-side solution, MTX has put a lot of engineering into its latest offerings. For example, the PROXP-20-THUNDER5 audio kit is a complete plug-and-play, five-speaker audio system designed for Polaris RZR platforms.

The heart of the system is the MTX AWMC3 media receiver that mounts in the upper dash factory panel and seamlessly connects to Bluetooth. Power for the system is provided by two amps—the included MUD100.4 4-channel and MUD600-1 monoblock. Front audio reproduction is handled by a set of PROXP-20-FS component speakers.

Exterior Sound Systems | THE SHOP
MTX delivers sound for side-by-sides including the Polaris RZR.

The lower 6-1/2-inch, rotationally molded speaker pod is designed to install in a matter of minutes and features integrated RGB lighting. A soft dome tweeter mounts in the upper dash top factory enclosure. Low end comes from the PROXP-20-SW subwoofer enclosure with a high output 10-inch subwoofer in a ported enclosure that mounts in the dash on the passenger side of the vehicle.

Rear sound is provided by a pair of MUD65PL speaker cans that also feature integrated RGB lighting in a compact design. Connections are made via integrated quick-connects and watertight harnesses built for off-road shenanigans.


Wet Sounds is known for creating super-loud wakeboard tower systems for ski boats. Now the company wants to take its knowledge of loud music off the beaten path.

At the recent MasterTech Expo in Arizona, the company brought along a new Jeep Rubicon and its new system designed for Jeep JKs. The concept vehicle is designed to appeal to the 4×4 and aftermarket communities as a plug-and-play system.

Jeep owners are usually amenable to modifying their vehicles with off-road equipment, and this system brings the party to the trail and campground.

Exterior Sound Systems | THE SHOP
Wet Sounds Jeep project

The demo Jeep is equipped with a Wet Sounds 6-channel marine amplifier; a 4-channel marine amplifier; four 6-inch, high-output coaxial speakers; two 12-inch, sealed-enclosure subwoofers; and two 12-inch marine tower speakers.

According to the company, the entire kit utilizes factory mounting locations with no cutting or modifications to the vehicle required. New speaker grilles were created that integrate into the factory mounting locations as well.

The design matches the aesthetics of the factory interior and is easy to install.

Wet Sounds ZERO Series component speakers were created specifically for Jeeps to sit stylishly in the dash, and the company’s DSP amplifiers are tuned so that the Wet Sound speakers are optimized. The system is tuned to sound great right out of the box.

A roto-mold enclosure was designed to house 2x ZERO Series 12-inch subwoofers and the amplifiers to set at the base of the back trunk area. This enclosure still provides enough airspace around the amplifiers for heat dissipation.

To mount the REV 12 HD tower speakers, aluminum mounting brackets were built to utilize the factory-threaded mounts on the roll bar. These tower brackets are currently only designed for a hardtop Jeep, but the company says there are future designs in the works.

A new wiring harness was designed specifically for Jeep vehicles as well. It is compatible with any aftermarket radio or can be used with the factory head unit. For ease of use, a tower and subwoofer master control unit was added to the center console.

Wet Sounds notes this plug-and-play design was created in hopes of attracting Jeep and off-road adventurers. It is a simple upgrade option or add-on with the engineering done in advance, making it easy for techs and their customers who want to get loud in a hurry.


Motorcycle audio has taken off recently, as the factory Harley-Davidson offerings are lackluster in the output department, especially for customers who install an aftermarket exhaust, as it is nearly impossible for a factory audio system to compete with open pipes.

In response, Rockford Fosgate has developed kits for 1998-up Harleys including Road Glides, Street Glides, Ultras and CVOs. The older models even include a new and updated source unit.

Exterior Sound Systems | THE SHOP
Rockford Fosgate complete front, rear, and subwoofer audio system (model HD14-STG5) custom designed for select 2014 and newer Harley-Davidson motorcycles.

Installing them is easy with the pre-engineered wiring harnesses. What is really cool is the new units add Bluetooth and SiriusXM capabilities that integrate with factory handlebar controls.

Those with 2014 and newer Road Glide or Street Glide models have a kit option that adds dual 10-inch saddlebag subwoofers with an additional 800W amplifier. The systems are custom-tuned for the motorcycle environment to overcome wind, road and exhaust noise. They are also designed to be exposed to the outdoors, so UV and rain will not damage them.

The lightweight speakers, called TMS, were designed with pro audio in mind. They are custom-tuned for the open-air environment, and the customer can keep it simple and relegate the upgrades to the fairing speakers or go all-out with additional bag lid speakers and Tour-Pak speakers/amplifier storage.

Brett Solomon

Brett Solomon is an editor and professional freelancer who writes about new models and the vehicle elecronic aftermarket.

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