The Klipsch Heritage line traces its DNA back to Paul W. Klipsch and his lifelong obsession with high efficiency horn loading. The founding idea was simple but demanding: a loudspeaker should reproduce the dynamic swing of live music without compressing, straining, or asking for enormous amounts of amplifier power. That philosophy, born with the Klipschorn in 1946, still informs everything wearing the Heritage badge. The Nines II carry that lineage into a fully modern context. They are a pair of powered stereo speakers that fold amplification, digital decoding, and even a phono stage into the cabinets themselves, aimed at a listener who wants the horn loaded Klipsch signature without assembling a rack of separates.
What follows is a deep dive into how The Nines II actually work, why each engineering decision was made, and what those choices mean when you sit down and listen.
Driver Design and Acoustic Topology
What is the tweeter and how does horn loading work here?
The tweeter is a titanium compression driver mounted on a Tractrix horn. In a conventional dome tweeter, the diaphragm radiates directly into the room. In a compression driver, the diaphragm is larger than the exit throat, and the sound is squeezed through that narrow throat before the horn flare expands it back out. This compression ratio dramatically improves the acoustic coupling between the diaphragm and the air, which is the core reason horn systems are so efficient. You get more usable output for a given amount of energy fed to the driver.
The choice of titanium for the diaphragm matters because a compression driver works its material hard. Titanium offers a high stiffness to mass ratio, which keeps the diaphragm behaving like a rigid piston higher into the treble before it starts to break up into unwanted resonant modes. The practical payoff is clean, extended high frequency detail with the sense of effortless dynamics that Klipsch listeners recognize immediately.
Why does Klipsch use a Tractrix horn instead of a plain flare?
The Tractrix horn is used because its specific mathematical curve controls how sound waves expand, producing more uniform directivity and reducing internal reflections and diffraction at the horn mouth. A Tractrix profile is derived from the tractrix curve, a flare geometry that keeps the wavefront expanding smoothly rather than abruptly. The audible benefit is twofold. First, dispersion is more controlled and predictable, so the tonal balance stays consistent across a reasonable listening window rather than collapsing the moment you move off axis. Second, controlled directivity means less sound splashing off your ceiling, floor, and side walls, so more of what you hear is the direct, intended output of the driver rather than smeared room reflections. That translates to sharper imaging and better intelligibility.
What does the 8 inch woofer contribute?
The 8 inch high output woofer handles the low and midrange frequencies and is sized to keep pace with the efficiency of the horn tweeter. Matching a woofer to a horn is a balancing act. The horn is inherently very efficient, so the woofer has to move enough air to keep the system tonally even. An 8 inch cone provides substantial radiating area, letting it produce authoritative bass and lower midrange with headroom to spare. Because this is a powered design, the woofer is driven by a dedicated onboard amplifier section, so the engineers could tune the amplification and the driver together as a single system rather than leaving that matching to chance with an unknown external amp.
How does the two-way design affect the sound?
A two-way design means the audio band is split into just two paths, one for the woofer and one for the horn tweeter, using a single crossover point. Fewer drivers and a single handoff between them reduces the number of crossover interactions and phase discontinuities that can smear timing and imaging. The tradeoff in a two-way is that each driver covers a wider band, which is precisely why the driver choices here matter so much. The horn loaded compression tweeter has the output capability to reach down and meet the 8 inch woofer cleanly, and the woofer has the excursion to carry the midrange without strain. When the pairing is right, a two-way rewards you with coherence, a sense that the music is arriving from one unified source rather than a stack of separate cones.
Enclosure and Build
What kind of enclosure is used and why a rear firing port?
The Nines II use a bass reflex enclosure with a rear firing port. A bass reflex, or ported, design uses a tuned port to reinforce low frequency output. The port acts as a Helmholtz resonator, using the mass of air inside it to extend and augment bass below the woofer's natural rolloff. Compared to a fully sealed box, this approach yields greater low frequency extension and higher efficiency, which suits the overall Klipsch high output philosophy.
Placing the port on the rear serves a couple of purposes. It keeps the front baffle clean, which helps minimize diffraction near the driver, and it lets low frequency energy load into the boundary behind the speaker. The practical consideration for you is placement. A rear firing port responds to the wall behind it, so pulling the speaker closer to the wall will generally add bass reinforcement, while more distance leans the balance tighter and leaner. This gives you a simple, effective tool to tune the low end to your room.
What are the cabinets built from and what finishes are offered?
The Nines II are available in multiple Klipsch finishes, consistent with the Heritage tradition of real wood cabinetry crafted with a furniture grade aesthetic. Heritage products have long been built to look at home in a living space rather than a studio, and the finish options let you match a room's décor. Beyond appearance, a well braced, substantial cabinet matters acoustically because it resists resonance. Any energy the enclosure walls absorb and re-radiate is coloration added to the sound, so a rigid, inert box lets the drivers speak with less interference from the structure around them.
Electronics, Power, and System Integration
How does the built-in amplification and power supply work?
The Nines II are powered speakers, meaning the amplification lives inside the cabinets rather than in a separate box. This is a significant architectural decision. When the amplifier is designed alongside the drivers, engineers can match the amp's characteristics to the exact load and behavior of the woofer and tweeter, and they can apply active signal processing and crossover work before amplification. The result is a system tuned as a whole. For you, it removes the guesswork of amplifier matching and speaker cables entirely. You connect a source and you are listening. The power supply and amplification are housed onboard, so the entire signal chain from input to driver is engineered and integrated by one team with one voice in mind.
What is the built-in phono stage and why does it matter?
The Nines II include a built-in switchable moving magnet (MM) phono preamp, which lets you connect a turntable fitted with a moving magnet cartridge directly without a separate phono box. A phono stage does two essential jobs. It applies substantial gain, because a phono cartridge outputs a signal far weaker than a line level source, and it applies the RIAA equalization curve, which reverses the inverse curve pressed into every record to restore correct tonal balance. Because it is switchable, the same input can serve either a turntable or a standard line level source depending on your setup, adding flexibility. Having this stage integrated means a vinyl front end is genuinely plug and play, which is a meaningful convenience for a listener who wants records without a separate equipment shelf.
What can you connect to The Nines II?
The Nines II offer a broad connectivity suite: HDMI ARC, Bluetooth, USB, network and optical digital, analog RCA, and the phono (MM) input. This breadth is the whole point of the design, since these speakers are meant to be the hub of a system rather than one component in a chain. HDMI ARC is the key here for television use, because the Audio Return Channel lets your TV send its audio back down a single HDMI cable to the speakers, so The Nines II can serve as the sound system for a display while keeping cabling minimal. Optical and network digital inputs give you clean digital paths from streamers, game consoles, and other sources, keeping the signal in the digital domain until it reaches the onboard conversion. USB allows a direct digital connection from a computer. Analog RCA covers legacy line level gear, and Bluetooth handles casual wireless streaming from phones and tablets.
Why does keeping signals digital until the last stage matter?
Feeding the speakers a digital signal over HDMI ARC, optical, network, or USB keeps the audio in the digital domain until it reaches the internal conversion and processing, which avoids unnecessary analog conversions along the way. Every time a signal is converted between analog and digital, or passed through extra analog stages, there is an opportunity to add noise or distortion. By accepting native digital inputs, The Nines II perform the digital to analog conversion once, inside the cabinet, right before amplification. That gives the design the tightest possible control over the entire chain and is a genuine advantage of an integrated powered system over a pile of separates connected by many cables.
Where The Nines II Sit in the Heritage Lineup
How do The Nines II fit within Klipsch Heritage?
The Nines II occupy a distinctive position in the Heritage family because they are a fully powered, all-in-one system rather than a traditional passive Heritage loudspeaker. Classic Heritage models like the Klipschorn, La Scala, Cornwall, Heresy, and Forte are passive designs that expect you to bring your own amplification and source components. The Nines II take the core Heritage values, horn loading, high efficiency, and real cabinet craftsmanship, and package them for a listener who wants the Klipsch sound with modern connectivity and no external electronics. Think of them as the Heritage philosophy translated into a self-contained, source-ready system.
Who are The Nines II for?
The Nines II are for a listener who wants serious horn loaded sound and broad connectivity in a two channel setup without building a rack of separate components. They suit the enthusiast who values the coherence of a true two-way with a titanium compression tweeter and an 8 inch woofer, who wants a real moving magnet phono input for records, and who appreciates that HDMI ARC lets the same speakers anchor a television and a music system at once. If your ideal is one elegant pair of Heritage cabinets doing the work of an amplifier, DAC, phono stage, and speakers together, The Nines II are built precisely for that.
Final Thoughts
The Nines II distill decades of Klipsch horn engineering into a modern, integrated form. The titanium compression tweeter on its Tractrix horn delivers the controlled directivity and effortless dynamics that define the brand, the 8 inch woofer and rear ported bass reflex enclosure supply the low end weight, and the onboard amplification, wide digital and analog connectivity, and switchable moving magnet phono stage make the system remarkably self-sufficient. For the enthusiast who wants the Heritage sound with the convenience of an all-in-one design, The Nines II make a compelling and technically coherent argument.