Hands-On Review:The benefits of JBL high-end research at low-end prices

JBL Products

By Jeff Wong


Using technology developed for their most expensive gear, JBL has created a line of PA cabs for the cash-challenged that really cuts it.


Test of fire
When they were delivered, the SoundFactor PA speakers looked plenty beefy, so I took them straight to a gig in a small outdoor amphitheater. The band I was mixing is a five-piece power-rock group who likes to play LOUD. When I got there I realized the place wasn’t as small as I’d remembered. I began to worry that the setup might be on the quiet side, especially for the bass.


For mains, I had a pair of the SF25 dual 15" two-way cabs with HF horns. A pair of SF12M 12" two-way cabs served as stage monitors, and I placed one SF15 15" two-way cab on either side of the audience as a side fill. Power came from a pair of Crown CE2000s.


I needn’t have worried about the SoundFactors producing enough volume. As it turned out, I didn’t have to drive them to anywhere near their performance ratings. And the sound was full, flat, and crystal clear with bass to spare.


JBL SF SeriesIllustrious history
I was definitely impressed with the quality of the SoundFactor speakers but hardly surprised. If I’d expect anybody to get it right, it would be JBL. They’ve been making speakers since 1947, which was pretty close to the dawn of the loudspeaker. Early on JBL got into theater sound, for which they’ve won Academy Awards and in which they still rule. By the mid ’60s JBL studio monitors were the standard worldwide.


JBL’s primary focus throughout has been quality. They have continued to develop new designs to produce the most accurate, complete sound possible. Throughout their history, they’ve authored a list of ideas and inventions as long as your arm, including the use of titanium in compression drivers.


Of course, they’ve come upon a number of ways to make components that perform well for a lower cost than the traditional methods. For example, they invented high-speed winding of voice coils and cast-iron pot structures. The SoundFactor series takes advantage of all those years of development to provide high-quality, high-power sound for prices way lower than comparable speakers on the market. And that’s not just hype—the performance of these speakers definitely backed it up.


Killer cabs
All the SoundFactor cabs are built of 3/4" MDF with advanced adhesives and closely spaced mechanical fasteners. They’re very dense and rigid, and this really seems to enhance the bass response. The inset handles are hefty steel bars. The fronts of the cabs are covered with 18-gauge steel grilles that cover not only the woofers, but the horns as well.


Mighty main
The SF25 comprises two 15" woofers with 2-1/2" edge-wound ribbon voice coils and a ferrofluid-cooled HF compression driver with a titanium diaphragm. The “Progressive Transition™” waveguide horn design provides great coverage control, reduced distortion, and smoother frequency response. What really makes this cab rule as a main is a special crossover design JBL calls “quasi three-way.” It rolls the mids off the lower woofer so that it works more like a built-in sub. With the upper 15" handling the mids and the horn taking the highs, I could drive the cab harder without muddying up the mids. It handles a massive 500 watts program.


Manly mid-sized
The SF15 sports a single 15" woofer and an HF compression driver with a PT waveguide horn design in a trapezoidal cab. Like all the SoundFactor speakers, it features SonicGuard™ high-frequency protection that saves your tweeter from dropped mics, feedback spikes, and just plain pushing too hard. It does this without degrading the rest of the signal with “poly-switches,” burning out fuses, or tripping breakers. I’ve replaced enough HF drivers to know this is a really significant benefit. The SF15 also shares with its brethren both Speakon® and 1/4" connectors, and it has a 35mm polemount cup. Its handy size and solid bass response make this one a good choice for a side fill, as I used it, or as a main for DJs and individual performers who need a reliable cab with big sound that they can move with no trouble. It handles 250 watts program.


Mondo monitors
The SF12M is equipped with a 12" woofer and a compression HF driver on a wide-dispersion horn. The trapezoidal cab is trim and angled just right for perfect floor placement. It also has a 35mm polemount cup so you could use it for a main in a small hall or for speech reinforcement. It’s very loud, with 99dB SPL, so it can crank out clear tone even with relatively lightweight amps. But it will handle 250 watts program. And when JBL says program, they mean it. Their 100-Hour Torture Test puts a 250W speaker through 100 continuous hours of 250W IEC noise with 1,000W peaks. Like all the SoundFactors, the SF12M features a crossover that was designed for JBL’s top-of-the-line gear using heavy coils with massive cores and heavy-gauge wire so they won’t saturate when you drive the speaker hard.


In sum, these cabs really rock. In my 25 years as an FOH sound man, I haven’t encountered cab designs that are this affordable with anywhere near this level of sound quality.



Features & Specs

  • 3/4" MDF advanced cab construction
  • 2 - 15" woofers with 2-1/2" voice coils
  • Ferrofluid-cooled titanium driver
  • 500W program handling
  • 2,000W peak handling
  • Advanced crossover topology
  • 4-ohm nominal impedance
  • 18.25"W x 43"H x 17"D
  • 94 lbs.



  • 3/4" MDF advanced trapezoidal cab construction
  • 15" woofer with 2-1/2" voice coil
  • Ferrofluid-cooled titanium driver
  • 250W program handling
  • 1,000W peak handling
  • Advanced crossover topology
  • 8-ohm nominal impedance
  • 18.25"W x 27"H x 17"D
  • 61 lbs.


  • 3/4" MDF advanced cab construction
  • 12" woofer with 2-1/2" voice coil
  • Ferrofluid-cooled titanium driver
  • 250W program handling
  • 1,000W peak handling
  • Advanced crossover topology
  • 8-ohm nominal impedance
  • 15.5"W x 22.5"H x 12.5"D
  • 43 lbs.