KLH
Henry Kloss's first act — affordable speakers that didn't compromise
History
KLH, founded in 1957 in Cambridge, Massachusetts, stands as a pillar of American high-fidelity audio history. The brand was established by three visionaries: Henry Kloss, a legendary audio engineer known for his work at Acoustic Research; Malcolm S. Low, a skilled businessman; and Josef Anton Hofmann, a concert pianist and son of the famed classical musician. Their mission was clear: to deliver scientifically designed, high-performance audio equipment at accessible prices. The name KLH was derived from the first initials of the founders’ last names—Kloss, Low, and Hofmann. KLH’s first breakthrough came in 1958 with the Model One, one of the earliest bookshelf speakers to utilize acoustic suspension technology, a revolutionary design pioneered by Edgar Villchur and licensed through Acoustic Research. This technology allowed for tighter bass response and reduced distortion in compact enclosures, making high-fidelity sound practical for average living rooms. The success of the Model One paved the way for a series of iconic speakers, most notably the Model Six in 1960—a floorstanding acoustic suspension speaker that became a benchmark for performance and value. Throughout the 1960s, KLH expanded its lineup with innovative products like the Model Eight, a combination FM radio and acoustic suspension speaker, and the Model Five, a compact speaker that became one of the best-selling hi-fi speakers of its era. In 1964, KLH was acquired by the Singer Corporation, marking the beginning of corporate ownership, though Henry Kloss remained involved until his departure in 1967 to found Advent Corporation. After decades of fluctuating ownership and brand dormancy, KLH was revived in 2017 under new stewardship, reintroducing modern versions of classic models while honoring the original engineering principles. Today, KLH represents a bridge between vintage American audio heritage and contemporary sound.Key Facts
| Fact | Detail |
|---|---|
| Founded | 1957, Cambridge, USA |
| Founder | Henry Kloss, Malcolm S. Low, Josef Anton Hofmann |
| First Product | Model One (1958) – Acoustic suspension bookshelf speaker |
| Golden Era | 1958–1970 |
| Famous Feature | Acoustic suspension design for deep, clean bass in compact cabinets |
| Current Status | Active under new ownership since 2017, producing modern reissues and new designs |
Legendary Products
Model Six (1960)
The KLH Model Six is arguably the most iconic speaker in the brand’s history. A three-way, floorstanding acoustic suspension design, it delivered remarkably flat frequency response (45 Hz–20 kHz) and 108 dB sensitivity. Its combination of scientific accuracy, neutral tonality, and affordability made it a favorite among audiophiles and institutions alike. Used in university listening labs and homes across America, the Model Six set a standard for transparent sound reproduction.Model Five (1968)
A compact two-way bookshelf speaker, the Model Five became one of the best-selling hi-fi speakers of all time. With its 8-inch woofer and acoustic suspension cabinet, it offered surprising bass extension and clarity for its size. Its affordability and performance made high-fidelity audio accessible to a generation of music lovers.Model Eight (1963)
More than just a speaker, the Model Eight integrated a high-quality FM tuner with an acoustic suspension enclosure. It was one of the first all-in-one systems to deliver true high-fidelity sound without compromise, embodying KLH’s mission of bringing quality audio to everyday consumers.Classic Models Reference
| Model | Era | Type | Power/Specs | Key Features |
|---|---|---|---|---|
| Model One | 1958 | Bookshelf Speaker | 45 Hz–18 kHz | First KLH model, acoustic suspension, compact design |
| Model Six | 1960 | Floorstanding Speaker | 45 Hz–20 kHz, 108 dB | Three-way design, legendary neutrality, studio standard |
| Model Five | 1968 | Bookshelf Speaker | 50 Hz–18 kHz | High sensitivity, mass-market success, compact bass |
| Model Seventeen | 1963 | Console Stereo | Tube amplifier, AM/FM | All-in-one system with premium KLH speakers |
| Model Twenty-Three | 1964 | Floorstanding Speaker | 40 Hz–22 kHz | Larger cabinet, extended bass, high efficiency |
Sound Signature
- Neutral and Transparent - KLH speakers are known for their flat frequency response and minimal coloration, ideal for accurate music reproduction. - Tight, Controlled Bass - Thanks to acoustic suspension design, bass is deep and articulate without bloat. - High Sensitivity - Most models are easy to drive, working well with low-power tube and solid-state amplifiers. - Open Midrange - Vocals and instruments are rendered with clarity and presence, a hallmark of New England speaker design.Collecting KLH
What collectors look for: - The Model Six and Model Five are the most sought-after, especially in original condition with working grilles and labels. - Original foam surrounds are often deteriorated; recapped or restored units command higher prices if done correctly. - Early production models (pre-Singer) are especially prized for their Henry Kloss-era authenticity. When buying vintage KLH gear, check for: - Integrity of foam surrounds and dust caps - Original drivers and crossovers - Cabinet condition—original finish and minimal veneer lifting - Presence of original grilles and hardware Typical price ranges: - Model Five: $150–$400 (restored) - Model Six: $400–$1,200 (pair, depending on condition) - Model Eight: $300–$600 Common issues include degraded foam, oxidized terminals, and failing capacitors in console models.Restoration Tips
Common service items include replacing foam surround kits on woofers, recapping crossover networks, cleaning pots and switches, and refoaming passive radiators on select models. Use period-correct components when possible to preserve authenticity.Competitors & Comparisons
KLH competed directly with Acoustic Research, Advent, and AR in the bookshelf speaker market. While AR focused on smaller dipoles, KLH offered broader lineups with more powerful bass. Compared to JBL or KLH, KLH’s sound is more neutral and less colored, favoring accuracy over excitement—a hallmark of its engineering-first philosophy.All Models in Archive (10)
Models
Audio Equipment
Speakers
- KLH-21-System - 1964
- Model Nine - 1968
- model-11
- model-12
- model-21
- model-345-(little-baron)
- model-eight-fm-radio - 1961
- model-eleven-portable-phonograph - 1963
- model-forty-one-reel-to-reel - 1966