The JL Audio MX series features a wide range of marine speakers and marine audio equipment. Every component and coaxial speaker is certified for marine-grade durability, which means it's capable of handling abuse from sun and water. In audio performance tests, the MX650 performed well enough to be a good option, but not quite good enough to be really impressive, especially considering the big price tag.
To test the audio performance, I recorded the MX650 as it looped a 20Hz to 20kHz sine tone. The tone was chosen because it reflects the full range of human hearing and is the best way to isolate the performance of the low, midrange and high frequencies. In addition to evaluating the speaker with my own ears, I used a frequency analyzer plugin to create a frequency signature. Then I graded the results.
In the audio performance test, the MX650 earned a B grade for the overall performance with a B+ for the highs, a C+ for the midrange and an A for the lows. The performance was good enough to make this one of the best speakers, but it is certainly not as well balanced as our top-ranked speakers. For example, the low-frequency performance is excellent and mostly comparable to the Clarion CMQ1622RL, but it can lead to an unbalanced performance with average midrange and highs.
The MX650 has a sensitivity rating of 89.5 dB, which is below average. This specification, which measures the volume at 1 meter using 1 watt of power, demonstrates the speaker's ability to convert power to volume. While sensitivity is important for all types of speakers, it’s especially important for marine speakers because you don’t have the acoustical advantage of a car, unless you install them in an enclosed cabin.
In the comparative loudness test, the MX650 earned an A- grade, which is surprising considering the sensitivity rating. In the test, I connected every speaker to the same stereo and measured the volume, from one meter, while playing a 500Hz tone at four volume levels. The idea was to put the sensitivity ratings to a comparative test with each speaker using the same amount of power and dealing with the same environmental issues, such as air pressure, humidity and altitude. This speaker was the third-loudest speaker overall, with only the JBL MS6520 and the Clarion CMQ speakers producing louder volumes.
The MX650 has pretty average power handling. The continuous power handling is 60 RMS watts, which is below average, but not by much. The peak power handling, which rates how much power the speaker can handle, is 225 watts, which is above average.
Every marine speaker on the market claims to have marine-grade durability, but most just meet the basic standards for water, UV and salt-fog (a saline mist) tests. JL Audio's MX series takes their testing beyond the basic standards, testing the speakers in specialized salt-fog chambers and ultraviolet chambers to simulate years of exposure to the elements on a boat. In other words, you can trust that the speakers are capable of handling the summers on the lake.
The tweeter is made of silk treated for a marine environment. The woofer, grille and frame are made of a polymer composite. The terminals are gold-plated brass, which is noncorrosive and optimal for signal transfer.
The MX650 from the JL Audio MX series is one of the most sturdy and durable marine speakers available. While the audio quality isn’t superb, it’s consistent and balanced. However, the power-handling specifications are nothing special, despite the excellent performance in the comparative loudness test.