JL Audio E-Sub E112 – Gloss Subwoofer
Like the US military, this US-made ‘tank’ is large, powerful and makes its presence known, writes Stephen Dawson.
Is ‘Made in the US’ still a selling point in Australia? Well, that’s what you’re getting with JL Audio. The company
has been making home audio products for 45 years and was one of the pioneers of quality car audio, especially with
But the present product is definitely a home subwoofer. A very impressive one. And it was made in the US.
What it is
The JL Audio E-Sub e112-GLOSS subwoofer is a high-powered home subwoofer. It is mid-sized, standing 412mm tall, 394mm wide and 467mm deep. Behind the removeable black grill, the 300mm woofer occupies almost all the baffle.
If weight is any guide to build quality – and it usually is – the JL Audio E-Sub e112-GLOSS subwoofer is extremely well built. At 33.3kg, the thing felt like it was loaded with cast iron bars. Even the holes into which the four thick lugs on the speaker grille are inserted look to be made of machined metal.
The controls are at the top back under a removable panel and, so, are easy to access. And even the panel over the
controls is heavy, made of a thick rubbery material, and it’s secured in place by magnets. It weighs 131g, or more than an iPhone 6.
A big part of the weight must be structural. That 300mm driver pushes a lot of air. JL Audio says it has an effective piston area of 545cm². That would be measuring to the mid-point of the rubber roll surround. Measuring the cone only, the area is 405cm².
The enclosure is sealed. That is, no passive radiator or bass reflex port. A naïve implementation of that kind of
design generally starts to roll off at a higher bass frequency that a bass reflex design, but rolls off at a gentler rate. So sometimes sealed enclosures provided the deepest bass. But these days we can’t assume a naïve design. The signal may well be processed internally to shape performance. As we’ll see later, there’s reason to suspect the use of a high pass filter in the design of the JL Audio E-Sub e112-GLOSS subwoofer.
In any event, a sealed enclosure with a large driver tends to require more power, and that’s what JL Audio has provided, with ‘1,500W RMS short-term’ available.
Combine a large driver, a mid-sized sealed enclosure and a lot of amplifier power, and you need a very sturdy box to avoid sympathetic resonances. Which is where a part of the 33.3kg comes from.
The finish of the JL Audio E-Sub e112-GLOSS subwoofer was immaculate. As the name suggests, it’s finished in a gorgeous piano gloss black. If style isn’t important – perhaps the subwoofer won’t be apparent to the eye — the JL Audio E-Sub e112-ASH is also available for $500 less.
Connections and controls
There are left and right line level inputs and outputs, and also speaker level inputs. The former are all RCA sockets.
The latter are in the form of Euroblock connections. The matching plug is included in the box.
Line level outputs on subwoofers are often mysterious in their properties. Do they just pass on the signal to other
devices? Or do they do something useful with the signal. In my experience, most subwoofer makers don’t actually say.
JL Audio does say. Specifically, it does both. The JL Audio E-Sub e112-GLOSS subwoofer has a two-way crossover built in. If it’s engaged – there’s an on/off switch, and the crossover frequency control knob – then the signal
to the woofer is low-pass-filtered to the crossover frequency and the signal to the line outputs is high-pass-filtered at
the crossover frequency. In both cases, a 24dB/octave Linkwitz-Riley design is employed. Which means that the
subwoofer is an ideal match for stereo systems with separate preamplifiers and power amplifiers.
In home theatre systems you will typically leave the crossover switched off and just feed the subwoofer output from
the receiver to one of the line level inputs. It doesn’t matter which one.
As I mentioned, the control panel is on the top at the rear. In addition to the crossover controls there’s a power switch – on/off /auto – level control, continuously variable phase control and a polarity switch.
An additional switch is at the rear near the line inputs. This can either ground or isolate the line inputs. That can be
useful to eliminate ground loop hums. I experienced no problems with the default setting.
JL Audio specifies the frequency response of the subwoofer (measured in n anechoic chamber) at 22Hz to 118Hz,
±1.5dB, with the -3dB point at 21Hz and the -10dB at 17Hz.
I played lots of my favourite bass stuff using a Denon AVR-X3500H receiver, including plenty of stereo music. The
system was calibrated by the receiver’s built in Audyssey MultEQ 32 processing. However I wound the system-determined crossover frequencies for the front three speakers up to 80Hz to make sure the subwoofer was handling more of the load. I left the surround and height crossovers at 120Hz.
The Telarc version of Bach’s Passacaglia and Fugue in C Minor – an organ work played on a huge machine with a 16Hz C-pedal – delivered a very solid performance on the dominant 32Hz harmonic. I had the grille off the subwoofer, and I could see the driver visible shifting to and fro.
Changing genre rather sharply, I spun some Eminem and Coolio. It was an interesting experience because I found
all manner of bass elements in both that I’d not previously suspected. When I listen to stereo music on that system I normally engage ‘Direct’ mode on the Denon. That switches off EQ and the subwoofer. My main speakers handle 40Hz easily, so I’m normally satisfied with bass extension. But now I hear that I’m missing things down there near the bass limits of audibility.
The Bach is good for assessing extension, but deep pipe organ pedals are slow in attack and decay, so of little
use is assessing timing. The kick drum on the Coolio was a different matter. It was powerful, rounded and perfectly timed.
Sealed subwoofers are generally better on that front. The JL Audio E-Sub e112-GLOSS subwoofer is about as
good as they get on that front.
Dinosaur footsteps on a Telarc surround sound test disc didn’t sound as deeply as they do with my regular subwoofer – it’s a lot bigger and handily reaches 16Hz – but the driver managed to deliver excellent impact without looking dangerously overdriven.
Indeed, that was the case with the selection of movies I tried. Excellent bite with each of them, and with enough energy in the 20Hz to 25Hz band to allow a visceral impact that says that, yes, this is a real subwoofer. And in no case did the subwoofer cone look physically distressed.
I measured the frequency balance output in two ways. First, I fed the unit with unprocessed pink noise – that’s random noise that diminishes in level at 3dB per octave, which is closer to the real-world tonal balance than white noise – and measured the output very close to the cone. The idea was to minimise room effects.
Second, I measured the subwoofer – same signal – with the microphone in the position at which the Audyssey
microphone had been placed for room calibration. In both cases, the subwoofer’s crossover was disengaged.
In the close position, I measured the output at 21.3Hz to 96Hz ±3dB (ignoring a couple of tiny spikes and dips
slightly outside that envelope). 20Hz was at -6dB relative to the average bass output. Below the 21.3Hz shoulder, output fell away at 24dB/octave. That’s steeper than you’d typically see with the aforementioned naïve sealed enclosure design. So I suspect that JL Audio has filtered out the deepest output. If so, that should allow
more headroom for the sounds within the subwoofer’s intended output range.
Measured from the calibration position, the subwoofer output was from 19.4Hz to 97Hz ±3dB. Again, that’s ignoring some tiny peaks slightly outside the envelope. But I must mention the big dip centred on 36Hz. That’s clearly a room mode – that is, specific to my room – that cannot be fixed simply by EQ, since increasing the level of those frequencies also increases the level of the destructive reflections.
That’s where you’d look at things like bass traps and other room treatments.
I think the most appropriate description for the JL Audio E-Sub e112-Gloss subwoofer is that it is a tank. It is
extremely well built. It is designed for a specific function, which is to deliver enormous amounts of clean bass within a defined bandwidth, and it performs this function well nigh perfectly. It’s only if you want significant levels of infrasonic bass that you need to look elsewhere.