The Klipsch La Scala AL6 is one of the purest expressions of a design philosophy that Paul W. Klipsch set in motion in 1946. Where most loudspeakers on the market use direct radiating cones fighting against their own inefficiency, the La Scala takes the opposite path: horn loading on all three drivers, from the 15 inch bass unit up through the treble. This is a fully horn loaded, three way floorstanding loudspeaker, and understanding what that means (and why Klipsch keeps building it in Hope, Arkansas) tells you almost everything you need to know about the sonic character and the engineering trade-offs baked into this cabinet.
This deep dive walks through each element of the design and explains the reasoning behind it. The goal is not just to list features but to show why each choice exists and what you actually hear because of it.
Design Philosophy and Topology
What does "fully horn loaded" actually mean on the La Scala AL6?
Fully horn loaded means every one of the three drivers, including the 15 inch woofer, couples to the room through a horn rather than radiating directly from a naked cone or dome. A horn is an acoustic transformer. It matches the high pressure, low velocity environment at the driver diaphragm to the low pressure, high velocity environment of the open air. Because that impedance match is far more efficient than a cone shoving air on its own, the driver does much less work for the same sound pressure level. The audible payoff is dynamic effortlessness: transients snap without strain, and the speaker sounds unforced even at high volume because the drivers are barely moving.
Why is the La Scala AL6 a three way design?
It is a three way design because dividing the audio band across three specialized transducers lets each one operate only where it performs best. The crossover splits the spectrum at 490Hz and 4500Hz, handing bass to the folded horn woofer, the critical midrange to a horn loaded compression driver, and the highest octaves to a compression driver on a Tractrix horn. Keeping each driver inside a narrow passband reduces intermodulation distortion (the smearing that occurs when one diaphragm tries to reproduce widely separated frequencies at once) and keeps directivity better behaved through the crossover regions.
The Drivers and Horns
How does the folded bass horn work?
The folded bass horn works by routing the output of the 15 inch (38.1 cm) woofer through a long, expanding internal path that has been folded back on itself so the horn fits inside a cabinet you can actually place in a room. Bass wavelengths are enormous, so a straight bass horn would be impractically large. Folding the path preserves the acoustic length needed to load low frequencies while keeping the enclosure to 38.5 x 24.25 x 24.5 inches (978 x 616 x 622 mm). The result is bass with exceptional speed and low distortion, because the woofer excursion is minimal. The tuning is the reason the quoted frequency response reaches down to 51Hz, and that lower limit is a direct consequence of horn geometry rather than a large ported box relying on cone travel.
What is a compression driver, and why use one for the midrange?
A compression driver is a transducer with a relatively large diaphragm coupled to the horn throat through a small opening called a phasing plug, which compresses the air and dramatically increases efficiency. For the midrange, this matters because the 490Hz to 4500Hz band carries most of the energy and intelligibility of voices and instruments. A horn loaded compression driver in this range delivers high sensitivity, tight control, and controlled directivity, so the speaker throws a stable, articulate midrange into the room without beaming or losing energy off axis. This is the band where the La Scala earns its reputation for presence and immediacy.
What does the Tractrix horn on the tweeter do?
The Tractrix horn on the tweeter shapes the dispersion of the high frequency compression driver using a mathematically derived flare based on the tractrix curve. The advantage of a Tractrix profile over a simple conical or exponential flare is smoother wavefront expansion, which reduces horn colorations and diffraction artifacts at the mouth. Audibly, that translates to treble that stays clean and open rather than honky or pinched, with a controlled dispersion pattern that keeps the tonal balance consistent as you move around the listening position. The tweeter takes over above the 4500Hz crossover point and carries the response to the stated 20kHz upper limit.
Why compression drivers for both midrange and treble instead of cones and domes?
Compression drivers are used for the mid and high sections because they provide the very high efficiency required to keep pace with an equally efficient bass horn. If the La Scala paired a horn loaded woofer with conventional direct radiators up top, the sensitivity mismatch would be severe and the crossover would have to pad the top end heavily, throwing away efficiency and introducing losses. Matching horn loaded compression drivers throughout keeps the whole system coherent in sensitivity and dynamics, which is what allows the overall rating of 105 dB @ 2.83V / 1m.
Crossover, Sensitivity, and Impedance
What do the 490Hz and 4500Hz crossover frequencies tell you?
The 490Hz and 4500Hz crossover points define where each driver hands off to the next, and they were chosen to keep each transducer inside its cleanest operating range. Placing the low crossover at 490Hz keeps the bass horn out of the vocal presence region and lets the midrange compression driver own the range where the ear is most sensitive to detail and timbre. The 4500Hz upper crossover keeps the tweeter handling only the top octaves, where a small compression driver on a Tractrix horn excels. The passive network doing this work must also correct for the natural response and phase behavior of horn drivers, which is why crossover design in a horn system is a demanding engineering task rather than a simple three way split.
What does 105 dB sensitivity mean for real world listening?
A sensitivity of 105 dB @ 2.83V / 1m means the La Scala AL6 produces very high sound pressure from very little input power, so it plays loud and dynamic with amplifiers that would struggle with typical box speakers. This is one of the defining traits of the design. Because efficiency is so high, low powered amplifiers, including single ended triode tubes and other flea power designs, can drive the La Scala to satisfying levels with headroom to spare. The practical benefit is that the speaker reveals the character of the electronics upstream, so subtle differences in amplification and source become clearly audible.
Is the 8 ohm nominal impedance easy to drive?
Yes, the 8 ohm nominal impedance is a friendly load that pairs well with a broad range of amplifiers, including tube designs that prefer higher impedance taps. Combined with the 105 dB sensitivity, this makes the La Scala forgiving of amplifier current delivery, since it demands so little power in the first place. That said, high efficiency cuts both ways: any hiss, hum, or noise floor in your electronics will be more audible through a speaker this sensitive, so clean upstream components are rewarded.
How should you read the 51Hz to 20kHz frequency response?
The 51Hz to 20kHz +/- 4dB rating describes the usable bandwidth within a four decibel window, which is an honest, real world tolerance rather than an idealized number. The 51Hz low end reflects the tuning of the folded bass horn, and while it does not chase the deepest subterranean octave, the bass it does produce is fast, articulate, and dynamically alive because it comes from a horn rather than a heavily excited cone. Listeners who want the lowest octaves can integrate a subwoofer, but the La Scala prioritizes midbass punch, transient integrity, and tonal accuracy over raw depth. The +/- 4dB window across the whole band is typical of a large horn system and reflects the interaction of three horns and their crossover.
Cabinet, Materials, and Build
Why is the enclosure made of plywood?
The enclosure is a folded horn built from plywood because plywood offers the stiffness to weight ratio and dimensional stability needed to form the precise internal horn geometry without unwanted panel resonance. In a horn cabinet, the walls are not just a box holding drivers; they form the acoustic pathway itself, so their rigidity and consistency directly affect the sound. Plywood resists the warping and flexing that would blur the bass horn's loading, and it has been the traditional Heritage material precisely because it delivers repeatable, durable results. The approximately 100 lbs (45.4 kg) weight per cabinet reflects the substantial internal structure required to fold a bass horn of this size.
What do the Heritage furniture grade finishes represent?
The Heritage furniture grade finishes mean each cabinet is finished to the standard of real furniture, with attention to veneer matching and surface quality rather than a utilitarian wrap. This matters because the La Scala is a piece of cabinetry meant to live in a room for decades, and the finish is applied as part of a hand building process. It is a functional statement as much as a cosmetic one: the same care given to the visible surfaces reflects the tolerances held throughout the build.
Why does "Hand built in Hope, Arkansas, USA" matter?
Being hand built in Hope, Arkansas means the La Scala AL6 is assembled in the same American facility that has produced Klipsch Heritage speakers, by people building cabinets that require careful hand work to fold and align a bass horn correctly. Horn cabinets do not lend themselves to fully automated mass production because the internal geometry and driver alignment demand skilled assembly. The practical benefit is consistency and accountability in a product designed to last, which is central to the Heritage promise of longevity and repairability.
System Integration and Placement
How do you get the best results from the folded bass horn in a room?
You get the best bass from a folded horn by using the room boundaries to your advantage, typically placing the La Scala near the front wall and often into or toward the corners. Horn loaded bass benefits from boundary reinforcement, and the design's bass mouth is intended to couple with nearby surfaces to complete its loading and extend low frequency energy in the room. Toeing the speakers in toward the listening position also takes advantage of the controlled directivity of the horns, tightening the central image and keeping tonal balance stable at the listening seat.
What kind of amplification suits the La Scala AL6?
The La Scala AL6 suits low to moderate power amplifiers because its 105 dB sensitivity and 8 ohm load ask for very little to reach realistic levels. This opens the door to amplifiers prized for tonal purity rather than brute wattage, including quality tube designs. Because the speaker is so revealing, the choice of amplifier and source becomes an expressive tool: the La Scala will faithfully broadcast the sonic signature of whatever you connect, so system matching is where much of the fun lives.
Where the La Scala AL6 Sits in the Heritage Line
How does the La Scala AL6 compare to the rest of the Klipsch Heritage range?
Within the Klipsch Heritage line, the La Scala AL6 sits as a fully horn loaded, three way floorstander positioned below the flagship Klipschorn while offering the same three way, all horn philosophy in a self contained cabinet that does not require corner walls to complete its bass horn. Compared with the Heritage models that use a direct radiating woofer, the La Scala's folded bass horn gives it a distinctly more efficient and dynamically effortless low end character. It represents the Heritage ideal in a form that many enthusiasts consider the sweet spot: uncompromised horn loading throughout, in a cabinet you can integrate into a normal listening room.
Conclusion
The Klipsch La Scala AL6 is not a speaker built to chase specifications for their own sake. It is an engineering statement about efficiency, dynamics, and coherence, achieved by horn loading a 15 inch bass driver, a midrange compression driver, and a Tractrix loaded compression tweeter, crossed over at 490Hz and 4500Hz, in a plywood folded horn hand built in Hope, Arkansas. The 105 dB sensitivity and 8 ohm load make it a canvas for expressive amplification, while the 51Hz to 20kHz response delivers the fast, articulate, and effortlessly loud presentation that has defined the Heritage sound for generations. For the experienced listener, it rewards careful placement and thoughtful system matching with a directness that few designs can match.