Aluminous Audio Loudspeaker System Review

September 15, 2014


In 2001, Krell introduced the LAT-1, a monitor loudspeaker in an all aluminum enclosure. Shortly thereafter, YG Acoustics began business and has been producing loudspeakers with all aluminum enclosures – and drivers – for more than a decade. Magico followed suit and now its complete lineup is all aluminum. Other companies have been slow to adopt this material, notwithstanding its extreme rigidity and non-resonant properties, no doubt because of the significant investment required to set up a CNC-controlled machine shop and acquire the raw materials necessary to fabricate the individual parts, internal structures and external enclosures in quantity. However, there is a new speaker company, Aluminous Audio, based in Spokane Valley, Washington, that has taken up the gauntlet, and released a sub/satellite system of entirely aluminum construction, mysteriously named the AL13.02 monitor and SU13.01 subwoofer. Okay, maybe it is not so mysterious, The AL stands for aluminum, the SU stands for subwoofer, and the numeric designations undoubtedly refer to version numbers, but the names do not exactly roll off the tongue. It is just further evidence of the no nonsense approach that Aluminous Audio, and its owner and speaker designer Luke Zitterkopf, brings to speaker fabrication.


The AL13.02 Monitors are rectangular in shape, vertically oriented, measure approximately 21″ tall by 6.5″ wide by 3.75″ deep, and weigh a surprisingly light 24 lbs. each. When locked in with their robustly constructed dedicated aluminum stands, the tweeter is raised to a height of 32″, somewhat below ear height in my listening setup, though I heard no untoward results, with the soundstage projected at a believable height. Although the monitors occupy the same footprint as a comparably sized floorstanding loudspeaker, they all but visually disappear in the listening room, something that will welcome them in a shared living/listening space and rate high on the spouse acceptance scale. The enclosures house a 1″ fabric dome tweeter and a 4″ midrange driver thus limiting their frequency response to 90Hz-20KHz. Each driver has its own crossover, low pass and high pass, comprised of a single capacitor and copper foil inductor, centered at 2500Hz with a 12db rolloff, without phase distortion. No resistors are used. It is a purist approach.


The SU13.01 subwoofer is a sealed design, likewise of all aluminum construction, measuring a compact 12.75″ wide by 12.75″ high by 14.5″ deep, the extra depth being required to house the in-built 175 watt Class D amplifier and comprehensive control panel. Four machined threads on the bottom accommodate spikes to firmly couple the subwoofer to the floor. The 70 lbs. weight helps enormously is this regard. The woofer driver itself is a 10″ aluminum cone unit with large and supple surround. All told, the frequency response of the subwoofer is 20Hz-120Hz, though no -3db specification is given. The back panel contains both high level and low level inputs, as well as continuously variable adjustment potentiometers for volume, crossover frequency, phase, and EQ frequency and level. Both the monitors and the subwoofers are of faultless construction. Someone knows their way around a CNC milling machine.



Setup of the main modules was a relatively easy affair. I started out placing them where I placed the Magico S1s which I reviewed last month. That got me close. However, I found that I could edge the monitors further apart and further into the room while still maintaining a strong center image, and at the same time widen the soundstage to the edges of the room and add depth which appeared to go beyond the front wall. Perhaps this was due to broader off axis response of the tweeters or the smaller front baffles, or both. Regardless, the effect was spectacular. For those keeping score, ultimate placement was approximately 28 inches from the sidewalls and 42 inches from the front wall, resulting in a spacing of 88 inches and a distance to the listening position of approximately 98 inches, all measured from the center axis of the drivers, and very close to an equilateral triangle.

Setup of the subwoofer took considerably more work. Given the location of my equipment rack and maximum length of my unbalanced interconnects, my positioning choices were limited to the front wall and the front half of each side wall. I ultimately found that the front right corner of the room, approximately 36″ in from the sidewall, gave the smoothest response at the listening position, and at that location the subwoofer gave no localization cues and simply disappeared. There was still the matter of dialing in volume, crossover frequency, and phase. Unfortunately, the dials were continuous rather than detented, so that going back and forth between settings gave only approximate repeatability, making the selection process a little more time consuming than it otherwise would have been, but ultimately satisfactory. The crossover dial was the most sensitive, but I found that by creeping up from lowest to highest frequency, the level for best integration was relatively easy to discern. Phase adjustment snapped into place.

Speaking of unbalanced interconnects, my listening setup was a Mac Mini to Debussy DAC, which has both balanced and unbalanced outputs. After consultation with John Quick at dCS, I was assured that the Debussy’s analog output stage was sufficiently bullet proof to drive both sets of outputs simultaneously, so I ran the unbalanced outputs directly to the subwoofer inputs and the balanced outputs directly to Pass Labs XA100.5 monoblocks and then on to the main modules. This eliminated my Meridian G02 preamplifier entirely from the equation. The subwoofer also has high level inputs so that, like the REL subwoofers, you can drive it directly off a stereo amplifier to retain ultimate voicing consistency, which is not possible with one subwoofer using monoblocks with independent grounds.

Given that the frequency response of the main modules is 90Hz-20KHz, the use of at least one subwoofer is required for full range sonic reproduction. Two subwoofers would of course be better for uniform bass response throughout the room, but at $5000 each, that would up the ante considerably. In my small room, with single listening position, one subwoofer was more than adequate. The main modules could of course be used as side and rear surrounds in a state of the art multi-channel or home theater system. Aluminous Audio has foreseen this contingency. The mounts on the rear of the floor stands can be unbolted and used as sturdy wall mounts.


My first impression was that the treble was over emphasized and that I was going to find the monitors too bright for my liking. In short order, I realized I was I was confusing detail and clarity with brightness. My ears quickly adjusted, for at no time did the loudspeakers become fatiguing, a sure sign of a problematic treble. The clarity of the treble opened a window on the recording providing space and air, and really superb imaging.


I often use harpsichord recordings to evaluate treble and, in particular, transient response. I listened first to baroque pieces composed by Armand-Louis, Francois, and Louis Couperin performed by Gustav Leonhardt, an acknowledged master of the instrument. Tracks 9-16 comprise L’art de toucher le clavecin, by Francois Couperin, and consists of eight preludes. These are relaxed in tempo. The harpsichord (or clavecin) is a plucked instrument (the strings originally having been pluck with quills), unlike a piano in which a felted hammer strikes the strings. It is what gives the harpsichord its distinctive sound, though limits its volume, and thus its venue generally to small halls or other intimate settings, though harpsichord performances are frequently heard in churches with close seating. Miking is relatively near the soundboard. As with any plucked instrument, transient response is critical, and with the Monitor 13.02s, the individual notes are sharply defined without being etched. Except when played rapidly, the notes do not run together, indicating the quickness of the drivers. This clarity gives even a harpsichord prelude a bit of anticipation and excitement. Notes are frequently sustained, and their decay is readily discernible and delicate. The overall tone of this recording is warm. At no time did I feel the speakers, despite their clarity and detail, were clinical or analytic.


Accurate vocal reproduction is a hallmark of a fine loudspeaker. After having heard Gillian Welch’s 2009 album The Harrow and the Harvest, I began exploring her back catalog. Hell Among the Yearlings, her 1998 effort, is particularly compelling. Orchestration is scant with Gillian on rhythm guitar and vocals and husband David Rawlings on lead guitar and backup vocals. The clarity of the AL13.02 monitors again shines through, rendering Gillian’s vocal clear and distinct, like a live mike feed, though clarity does not come at the expense of either chestiness or sibilance. The midrange is not overly warm, actually remarkably neutral, with no audible evidence of the effect of the crossovers. In other words, driver transition is seamless. Imaging is razor sharp, with Gillian front and center, and David’s backup vocals a little behind and to the right. As with the harpsichord, the picked strings of the guitars are exceptionally clean. Reproduction of the timber of the acoustic instruments was remarkable. I find the simple arrangements, without a lot of processing, intimate and authentic. I’d love to hear her at the Bluebird Cafe. One thing that is interesting to note is that the mastering engineer was not able to homogenize the sound, with different cuts clearly recorded by different mics in different locations. That the Aluminous Audio combo was able to present the differences so readily says a great deal about their accuracy.


Neither the harpsichord nor the girl and guitar selections address the integration of the subwoofer and the bass, however. For that I turned to Diane Krall’s ubiquitous Love Scenes, which every audiophile knows all too well. The opening cut, All or Nothing at All, is the single best cut I know of recorded acoustic bass. In this case, it is located dead center and carries the beat. In an overblown system – you know with the subwooofer volume turned up too high – it dominates and distracts from the music. But when dialed in correctly, it is concise and controlled, and sets the beat and the foundation for the music, but does not overpower it. The SU13.01, when set up properly, accomplishes that. It leaves the acoustic bass on stage where it belongs, rather than under your listening chair. The SU13.01 also provides the necessary weight to the piano, portraying it realistically. Integration of the AL13.02 monitors and SU13.01 subwoofer was flawless, achieving a completely coherent soundstage. With the volume cranked up, the loudspeaker combination showed no evidence of strain, and the dynamics were startling.


Many loudspeaker manufacturers offer monitor loudspeakers and subwoofers separately, but no other manufacturer that I know of, at least in this price category, offers the integrated combination Aluminous Audio does with its AL13.02 and SU13.01. That they were designed to complement one another is evident upon first listen. Each has its own positive attributes, but the synergy that arises when using them together makes them special. The subwoofer, once sited and adjusted properly, offers everything I remember the JL Audio F112 offering, in a smaller, better looking and more inert enclosure with more flexible adjustments and high level inputs. The AL13.02 is neutral, clean, clear, and detailed without being clinical. This price segment is crowded, but the Aluminous Audio combination more than holds its own. Together, they offer an outstanding alternative to the traditional self-contained floorstanding loudspeaker, allowing you to optimally place the low and high frequency elements for both imaging and bass integration simultaneously. Did I mention they look stunning? An impressive entry for this new company.

- Frank Berryman


AL13.02 Monitor

• Frequency Response: 90Hz – 20kHz
• Impedance: 4 ohms nominal
• Sensitivity: 87dB
• Recommended Power: 20W – 200W @ 8 ohms
• Enclosure: Aluminum sealed-cabinet alignment
• Dimensions: 21-inches x 6.5-inches x 3.75-inches
• Weight: 24lbs each
• Finishes: Diamond Black or Sonic Silver
• Includes: 2 x 13.02 Monitors, stands, floor spikes

SU130.01 Subwoofer

• Frequency Response: 20Hz – 120Hz
• Amplifier: Class-D
• Amplifier Power: 175W
• Driver: 10-inch aluminum driver
• Enclosure: Aluminum sealed-cabinet alignment
• Dimensions: 12.75-inches x 12.75-inches x 14-inches
• Weight: 70lbs
• Finishes: Diamond Black or Sonic Silver
• Includes: 13.01 Subwoofer, floor spikes


Aluminous Audio
Spokane Valley, WA. 99206
Telephone: (509) 434-8889

Associated Equipment

Analog Source: VPI Scout; Dynavector 20X2; Musical Surroundings Phonomena II
Digital Sources: Meridian G08; Mac Mini; dCS Debussy; Audirvana Plus
Preamplifier: Meridian G02
Power Amplifiers: Pass Labs XA100.5
Loudspeakers: Magnepan 1.7
Analog Cables: Kimber Select KS1016 and KS1116
Digital Cables: Kimber Select KS2020 and KS2436 USB
Speaker Cables: Kimber Select KS6063 and KS9033
Power Cables: Kimber PK10G and PK14G
Headphones: Etymotic ER-4S
Accessories: Audience aR2p power conditioner