Напольная акустика — Klipsch FORTE IV

The Forte IV belongs to the Heritage line from Klipsch and is a three-way tower using a 12 inch woofer with horn-loaded midrange and tweeter. The original Forte arrived in 1985. Klipsch brought the name back into the Heritage range in 2017, and the fourth generation adds updated cosmetics and revised acoustic engineering while keeping the basic layout of the original. Cabinets are still produced by craftsmen in Hope, Arkansas.

Key specs that matter

Frequency response is 38 Hz to 20 kHz within plus or minus 3 dB. Klipsch quotes sensitivity of 99 dB at 2.83 V and 1 m, taken in a typical room, and nominal impedance is 8 ohm. Power handling is 100 W continuous and 400 W peak, and maximum output is 116 dB continuous. The crossover hands over at 650 Hz and 5.2 kHz. Each cabinet is 90.81 cm high, 42.24 cm wide and 33 cm deep and weighs 32.7 kg.

Engineering and use context

A K-100-TI compression driver with a 1 inch titanium diaphragm sits on a K-79T horn and carries a newly designed wide dispersion phase plug. For the midrange Klipsch uses the new K-702, a 1.75 inch compression driver with a polyimide diaphragm, mated to the K-703-M horn, a modified Tractrix design with the patented Mumps technology for even polar response through the mid frequencies. Bass comes from a K-281 fiber-composite cone woofer working with a rear-mounted KD-15 passive radiator of 15 inch size, which is driven by the acoustic pressure of the active woofer to extend the low end. The network was completely revoiced using higher grade parts and draws on the steep-slope three-way design of the Klipschorn and La Scala. The cabinet uses 19 mm MDF, and the input panel is aluminum. Veneers are book-matched, and each pair is grain-matched from the same timber and labeled with sequential serial numbers. Finishes listed are American Walnut, Natural Cherry and Black Ash with salt and pepper grille cloth, and Distressed Oak with lambswool grille cloth. Klipsch gives a 10-year warranty on Heritage Classic speakers.

Pairing

Two sets of binding posts permit bi-wiring with one amplifier or bi-amping with two, splitting the woofer section from the horn-loaded upper drivers. The high sensitivity figure means the speaker reaches its rated output with modest amplifier power, so low-output amplifiers are a workable choice.

Alternatives

The Klipsch Heresy IV is a smaller three-way Heritage floorstander built around an equally sized woofer, a rear Tractrix port instead of a passive radiator and crossover points of 850 Hz and 4.5 kHz.