KLH Model Four Floorstanding Speakers - Pre-order

A sealed box, in a world that went ported decades ago

The KLH Model Four is a three way acoustic suspension floorstander, which is the technique Henry Kloss helped pioneer in the 1950s and the one KLH has never abandoned. There is no port, so the bass is tight and predictable rather than boomy and room dependent, and KLH says the cabinet can sit as close as six inches from a wall. It slots between the Model Three and the Model Five, sharing the Model Five's midrange and tweeter with the Model Three's woofer. Sold as a pair.

Why You'll Love It

• Sealed bass behaves in real rooms. Acoustic suspension rolls off gently instead of falling off a cliff below the port tuning, which is why these stay clean close to a wall where a ported speaker would boom.
• A tone control built into the speaker. The three position Acoustic Balance Control on the rear panel trims everything above 400Hz by 1.5dB or 3dB, so a bright room can be fixed at the speaker rather than in the amplifier.
• Real veneer and a proper grille. Three quarter inch and one inch MDF wrapped in real wood veneer, with a magnetic knit grille in a period fabric matched to each finish.

Under the Hood

• Three way acoustic suspension design with an 8 inch pulp paper woofer on a 1.5 inch flat wire voice coil, a 4 inch pulp paper midrange, both on reverse roll rubber surrounds, and a 1 inch aluminium dome tweeter.
• Second order electro-acoustic crossover at 380Hz and 2,500Hz, with frequency response of 46Hz to 20kHz ±3dB and low frequency extension to 35Hz at -10dB.
• Nominal 6Ω load dropping to 3.5Ω at 120Hz, in-room sensitivity of 88dB at 2.83V and one metre, handling 150W continuous and 600W peak.

CHT Insider Verdict

Sealed floorstanders are rare now and this is a good demonstration of why they should not be. The bass goes lower than the numbers suggest because the roll off is gradual, and the wide baffle gives it a big, unfussy soundstage that suits a lounge rather than a nearfield triangle. Two practical notes. It dips to 3.5Ω, so give it an amplifier that is comfortable below four ohms rather than the cheapest thing with the right power rating. And there is a single pair of binding posts, so bi-wiring is not an option.

Pro Tip: Leave the Acoustic Balance Control on MID to start, which is where KLH ships it, and only move to LO if the room is hard surfaced with glass and tiles. Moving it to HI is for heavily furnished rooms with rugs, curtains and soft furniture. It is a genuinely useful control and most people never touch it.