Henry Kloss knew the AR-3 was a landmark. He’d helped design it. But that tweeter — the one that sprayed detail like broken glass? He couldn’t live with it. So when he left AR to start KLH in 1957, he set out to build a compact speaker that delivered the same deep bass and flat response without the ear-fatigue. The Model Six, released in 1965, was his answer. And it changed everything.
The cabinet is small — about 20 x 11 x 9 inches — but it’s not a wimp. That’s the acoustic suspension magic: a sealed box, a long-throw woofer with a compliant cloth surround, and a tweeter that knows its place. The crossover is simple, second-order, set at 1.5 kHz. No ferrofluid, no exotic materials. Just good engineering and a lot of cotton wadding inside to damp reflections.
Sound? It’s warm. Deep, round, very American. The bass doesn’t thump — it blooms, like a cello in a small room. The midrange is liquid, almost syrupy, with voices floating on a bed of air. The highs are rolled off gently, so cymbals and brushes never bite. On a bright recording, the Model Six acts like a polite filter. On a great recording, it just sounds right. You don’t hear the speaker. You hear the music.
What makes the Six special is its balance. Many vintage speakers are either too forgiving (no detail) or too revealing (harsh). The Six sits in a sweet spot: detailed enough to hear finger squeaks on guitar strings, but smooth enough to play all day. It’s also easy to drive — 8 ohms, 92 dB sensitivity. An old 20-watt receiver will make them sing. And they’re still affordable, usually $200–500, because they aren’t as famous as the AR-3 or the Large Advent.
The honest caveat: the tweeters are fragile. The original cone tweeters can fail — the voice coil former dries out, the surround rots. Replacements are available but not cheap. And the foam grilles? They turn to dust. You’ll likely need to refoam the woofer surrounds too, or find a pair that’s already been serviced. Factor in $150 for a recap and refoam.
But once they’re right, they’re right. The KLH Model Six isn’t a speaker you upgrade from — it’s a speaker you settle into. It asks nothing more than a good amplifier and a tube of wood polish. Sit down, put on something recorded before 1975, and let the music wash over you. You won’t miss those harsh highs for a single second.