During the pre-internet 1970s through the mid 1990s the only source of speaker information came from audiophile magazines, word of mouth, and dealer advice. Retailers such as Circuit City and Best Buy barely existed and audio stores tended to be small "mom and pop" salons. In addition, many dealers had a brand "exclusive" as the only store to carry a particular brand in their area. So if you were in the market for new speakers the process was that well-armed with your research you went store to store, talked to the experts, and spent time demoing different brands to find your favorite.

Popular speakers of the period were Polk Audio, Boston Acoustics, Mission, Infinity, Advent, & JBL. But despite their sound quality all were limited by the common bass-reflex design that only produced 87-91db @ 1 watt. Even with several hundred watts pushing them it was difficult to reach satisfying volumes. This was compounded by the widespread use of low-power (25-50 watt per channel) receivers on the market. So when CD players arrived in 1983 with digital response from 20HZ-20khz and a large 96db dynamic range people were in for a shock. On deep bass notes woofers would over-excurse and pop and when percussive music was turned up the receivers clipped and tweeters quickly burned out. At my stereo store I remember every Monday customers would bring in speakers with blown tweeters for repair after weekend parties.

PAUL KLIPSCH was a legendary name in the audio field. Since 1946 his company in Hope, Arkansas had been well regarded for its highly-efficient speaker systems. By using a horn on the tweeter, midrange, and even woofers Klipsch speakers were capable of producing 98-104db using only one watt. This meant that a tiny receiver could reach volumes that would require several hundred watts on other speakers. Now known as the "Heritage Premium Audio" series, the original models the Klipschorn, Belle, La Scala, Cornwall & Heresy were capable of high performance but were aimed at a more Bohemian segment than the precise salon speakers favored by the audiophile crowd. Most magazines avoided reviewing Klipsch speakers considering them coarse and a common perception was that they had a "horn sound". Truthfully they averaged 50hz-17khz ± 5 db which even by 1980's standards was ragged. Loud yes, precise no.

Emboldened by the clarity of the CD and the emergence of home theater and Dolby Surround, Klipsch went back to the drawing board and in 1985 the Forte was released. True to Klipsch speaker philosophy it had a horn tweeter and midrange and a sensitivity of 98db @ 1 watt. Time spent tuning it in an anechoic chamber resulted in a more desirable 32-20khz ± 3db. In a dealer's listening room it would leave customers laughing due to its clarity and effortless, powerful sound. Other dealers did their best to downplay Klipsch but found it difficult when comparing them to their own fragile salon models.

Klipsch advertising of the period pointed out that high sensitivity allowed a low powered receiver to be used. However the opposite was true too. Using a high-wattage amp the Forte produced amazing results with powerful deep bass and startling slam. CDs with EDM or pipe organ would literally shake the building. Dealers knew this and it was common to pair them with large Hafler or Adcom amplifiers on the showroom floor. In 1989 I bought a new set of Black Lacquer Fortes and had the rear labels signed by Paul Klipsch at the factory. The crossover is installed inside the rear of the jack panel. A large iron core inductor is on the woofer and an air core inductor on the tweeter. Capacitors were blue KSC (King Sun) mylars and one KSC electrolytic on the woofer. An interesting factoid is that the midrange was wired out of phase compared to the tweeter and woofer. This is typical of long midrange horns to maintain signal alignment.

A transformer is used on the midranges of the Heritage model speakers to match volume instead of using a resistor. Paul Klipsch maintained as far back as the 1950s that using a transformer to reduce output was better sonically and electrically than a resistor. His tests showed transforming the signal instead of "padding it down" resulted in better peak dynamics and increased the damping factor at the amp.


STEREO REVIEW MAGAZINE, JULY 1986
Stereo Review magazine was mainstream and owned by CBS. It's monthly issues reviewed many popular products making it one of the only sources of a Klipsch Forte I review.

"The room response was one of the widest and smoothest we've ever measured varying only ±2db from 230hz to 20khz, the Forte's low frequency distortion was by far the lowest we have ever measured from a speaker. Its distortion and sensitivity measurements are so outstanding that comparison with most other speakers is impossible."

EXOTIC WOOD VENEERS

By the late 1980s digital audio and home theater was in full-swing and Klipsch products were perfectly placed to take advantage. In 1989 Klipsch retired the original Forte and released an updated version called simply the Forte II. Height and width were identical but the cabinet was 1/4" deeper. The rear passive radiator had been increased from 12" to 15" and a new 12" front woofer was used. It retained the same tweeter but most significant was a new large-throat midrange called the "Tractrix" intended to produce a wider soundfield. Both models were rated to take 100 watts continuous but the Forte II carried a new spec of "500 watts peak". Frequency response was the same but sensitivity had increased to 99db/1 watt. The crossover values were slightly different. An invisible change was that the rubber grommets that held the grill on had been replaced with magnets.

In 1991 I bought a new set of Forte IIs directly from the Hope Arkansas factory. With the exotic veneers no longer in production I decided on a set in Oak Oil with brown grills. I was able to have Paul Klipsch sign these labels as well.

In the 2000s on my Forte I crossover I kept the stock values and switched out the film caps for Dayton 1% PPs, an audio-quality resistor, and upgraded the woofer's electrolytic capacitor. I also upgraded the tweeter coil to a larger gauge air coil. In 2008 I replaced the tweeter and midrange diaphragms with new factory versions to refresh them. I found the speakers clear and open with a natural, dynamic sound.

BELOW: My Forte II crossover had a physically smaller iron core coil and transformer compared to the Forte 1. The board was lighter weight and oddly marked with Forte I values and Forte II parts. Its as though Klipsch created a new board late in the Forte 1 production and carried it over Forte II as well. In the photo below I was experimenting with Dayton PPs and a modern electrolytic.

MODERN MODS

If you have never heard a Forte your first listen is an eyeopener. Its a broad, open, dynamic sound that seems to leap out of the cabinet. With a high power amplifier it produces a clear treble and an exciting, live effect. I find the bass deep and musical.

FORTE II