Paul W. Klipsch started building speakers in a tin shed in Hope, Arkansas in 1946, and the company built its big horn models there. Listings call the Klipschorn, La Scala, Belle, Cornwall and Heresy the Heritage line, but Klipsch marketing coined that name after 1997, so it isn't what owners called them at the time. The Heresy and Cornwall were both reworked in 1985, the Forte got new horns in 1989, and the KG 4 belongs to a different family. Here's how to tell the generations apart.
The Heresy I
The Heresy arrived in 1957 as effectively the world's first commercial center-channel speaker, built to sit between two Klipschorns in a three-channel system. The name came from an associate who said a Klipsch that didn't go in a corner would be heresy. Klipsch replied, "That's exactly what I'm gonna call it!" A Heresy sat between two Klipschorns at the 1958 Brussels World's Fair, and a Klipschorn and Heresy system was demonstrated in Moscow in 1959 at the exhibition remembered for the Nixon and Khrushchev kitchen debate. It later became a bestseller with churches.
Klipsch just called it the Heresy, and Heresy I is the collector name for the version made until 1985. The Heresy I is a three-way in a sealed box, about 15½ inches wide, 21½ inches tall and 13¼ inches deep, and it weighs 23 kilograms, about 51 lb. The woofer is a 12-inch K-22 and fires directly. The midrange is a K-55 compression driver on a K-700 horn, and the tweeter is a K-77. It's rated at 96 dB with an 8-ohm load. Most important for identification, the Heresy I has a removable back.
The Heresy II
In 1985 Klipsch made changes and re-released it as the Heresy II. The easy tell comes from Crites Speakers, a Klipsch restoration supplier. On a Heresy II, the back doesn't come off and all of the drivers mount through the front of the cabinet. So if you can see the driver bolts from the front and the back panel is fixed, you're looking at a II or later. To reach the crossover on a II, Klipsch's own instructions have you remove the screws in the rear input cup and pull the network out through the hole.
The II still has a 12-inch woofer and a horn-loaded midrange, and Crites lists its midrange diaphragm in the K-52-K and K-53-K phenolic family. The Heresy III replaced it in 2006 with a more powerful woofer, a bi-wire network and titanium-diaphragm compression drivers. A Heresy II has none of those, so a listing claiming titanium drivers or bi-wire terminals on a II describes either a later model or a modified one.
The Cornwall and Cornwall II
Klipsch designed the Cornwall in 1959 as a fuller-range alternative to the Heresy for the center channel between two widely spaced Klipschorns. It debuted at the New York Audio Fair, where a naming contest landed on Cornwall because it could go in a corner or against a wall. Its woofer fires directly from a vented box, with the midrange and tweeter on horns.
Early Cornwalls are a provenance story. Klipsch says the first ones used Electro-Voice and Jensen components, later replaced by Klipsch's own drivers. An early Cornwall with Klipsch drivers carries a 15-inch K-33 woofer, a K-55 midrange on a K-600 horn and a K-77 tweeter, with access from the rear. An early pair still on EV or Jensen parts is a different, older animal, so ask for photos of the driver labels.
The Cornwall II came in 1985 with the same change as the Heresy II. The back isn't removable and all the drivers mount from the front, including a front-mount 15-inch woofer. Its midrange uses a diaphragm from the same K-52 and K-53 phenolic family. Crossovers differ by generation as well. We couldn't confirm a factory weight, but it's a big 15-inch box, so plan for a heavy lift.
The Forte and Forte II
The Forte arrived in 1985, developed by Paul Klipsch and chief engineer Gary Gillum, the first chief engineer Paul Klipsch hand-picked as his successor. Klipsch insisted that every speaker be fine-tuned by ear, the crossover especially. Demand ran so high that Hope went to around-the-clock production, and Klipsch calls it one of its best-selling speakers of all time. It pairs a direct woofer with a passive radiator on the back and horn-loaded mids and highs.
In the late 1980s Roy Delgado and Jim Hunter refined it with Tractrix horn technology, and that became the Forte II in 1989. So the Tractrix-style horns mark a Forte II, made until 1996, and the original Forte predates them. Crites sells separate crossover rebuild kits for the Forte and the Forte II, so tell the seller which one you have before you order parts. Check the passive radiator on the back for damage too, since it sits where it gets bumped.
The KG 4
The KG 4 is a two-way. Klipsch's own page calls it the two-way KG Series KG 4 floorstanding loudspeaker and dates it to 1985 to 1992, when the KG 4.2 replaced it. It has no midrange, and only the tweeter is horn-loaded, so a listing that describes a three-way KG 4 has it wrong. The KG line ran from the KG 1 to the KG 5.5. New KG 4 crossovers and capacitor rebuild kits are sold, so ask whether a pair has been recapped.
Driver numbers and replacements
Replacement drivers are common on all of these, and some are good. Crites sells drop-in substitutes for the K-77 tweeter (the CT110 and CT120), for the K-55 midrange (the A-55G and the Atlas PD-5VH), a 12-inch woofer for the Heresy I and II (the CW1228), a 15-inch woofer for the Cornwall (the CW1526) and a front-mount version (the CW1526F). It also sells the G-700 horn to replace the Heresy's K-700. None of that is a reason to pass, but it changes what you're buying, so ask which drivers are original and look for matching labels on both speakers.
Recapped crossovers
Crites calls capacitors the main wear item on Klipsch crossovers and says caps over about 20 years old are due for replacement. Klipsch itself refers Heritage crossover repairs to authorized dealers. A recap is normal on any of these speakers and isn't a mark against them. Ask whether the caps were replaced on the original boards or the networks were swapped for new ones, and ask for a photo. Model-specific boards exist, like the Type E for the early Heresy and the Type B for the early Cornwall, so the network should match the generation.
What to check
- Generation. Look at the photos for driver bolts on the front and a fixed back. That means a 1985 II or later.
- Driver labels. Ask for photos of each driver's label. They should match the generation and each other.
- Crossovers. Ask whether they've been recapped or replaced. The network should suit the model.
- Horns. Check the photos for cracks or chips at the horn mouths. They should be clean and firmly mounted.
- Rear passive. On a Forte, ask for a photo of the back. The passive radiator should be intact.
At 96 dB, a Heresy runs happily on a small amp, and our amp matching guide explains why. See all of Klipsch, the horn speakers, or browse everything.