Klipsch Epic CF-1 Floor standing speakers
The new Epic Series of loudspeakers from Klipsch & Associates features what the company calls "controlled focus" design. Rather than referring to a single characteristic, this term represents a group of design features intended to make the Epic series equally suitable for home theater and conventional home audio applications.
The Epic Series consists of four models, differing in size and other specifics but sharing the same basic design. They are floor-standing speakers, with a pair of vertically aligned woofers surrounding a horn-loaded tweeter (the well-known D'Appolito configuration) normally covered by a removable black cloth grille. The port of the vented enclosure is located at the bottom of the front panel.
Klipsch speakers have always been noted for their high efficiency, and the Epic series is true to its heritage with sensitivity ratings ranging from 96 to 102 dB sound-pressure level (SPL), substantially higher than most other speakers intended for the home market. The Epic Series drivers use powerful neodymium magnets located inside the voice-coil assembly, which Klipsch says not only improves performance but also provides the "shielding" required for speakers that may be located close to a video display.
The CF-1, which we tested, is the smallest and lowest-priced of the Epic systems. Its 6-1/2-inch woofers, which have blended polymer and graphite cones, hand off to the tweeter at 2.2 kHz with crossover slopes of 18 dB per octave. The high-frequency driver, which has an aluminum diaphragm, is coupled to a rectangular third-generation Tractrix horn, whose mouth measures approximately 5x9 inches. This horn, similar to the ones used in the company's Home THX speakers, has a rated dispersion of 90 degrees horizontally and 60 degrees vertically. Klipsch says the speaker's radiation pattern covers the intended listening area to provide stable imaging while minimizing reflections that could color the sound.
Klipsch notes that the crossover is set at the frequency where the woofer's horizontal dispersion matches that of the horn tweeter and that the D'Appolito driver configuration places the acoustic center of the entire speaker's output at the center of the horn, creating the effect of a 60-degree vertical pattern in the crossover region for the total system. The design aim was to create the aural illusion that all the sound radiates from one full-range driver.
The CF-1 enclosure is fitted with spiked feet, which is claimed to reduce low-frequency coloration and improve overall detail. Removable spike caps are provided to protect the floor from damage and to simplify positioning the speaker on a carpet.
Klipsch recommends that the CF-1 speakers be spaced about two-thirds as far apart as their distance from the listener and points out that (as with any speaker) their bass performance will be affected by the proximity of the walls behind and beside them. The company also suggests that for best imaging the horn should be aimed at the listeners' ears, by toeing them in as necessary and possibly tilting them back slightly.
For measurement and listening, we placed the Klipsch CF-1 speakers approximately as recommended. The room response, averaged for the left and right speakers, was exceptionally flat, within +2 dB from 70 Hz to 10 kHz. The averaged output between 10 and 20 kHz was a couple of decibels higher than at lower frequencies and did not drop below the overall average up to our 20-kHz measurement limit. This measurement was consistent with a quasi-anechoic MLS response measurement at a 2-meter distance.
The close-miked woofer response, essentially flat from the crossover frequency down to about 70 Hz, reached a maximum of +6 dB at 50 Hz and fell off to -6 dB at 32 Hz. It spliced easily to the room response to produce a composite response of 32 Hz to 20 kHz +/-6 dB.
Measured sensitivity was 92 dB SPL at 1 meter with a 2.83-volt input of pink noise. Although that is short of the system's 96-dB rating, it was measured in a totally different environment than that used by the manufacturer and is still high by home loudspeaker standards.
At an input of 2.25 volts, corresponding to our 90-dB reference output level, the system's bass distortion remained between 0.6 and 1.5 percent from 50 Hz to 2 kHz, rising to 3 percent at 40 Hz and 6 percent at 30 Hz - excellent performance for a pair of 6-1/2-inch drivers.
The system impedance was typically between 4 and 5 ohms from 90 Hz to 2.2 kHz, with high readings of 25 ohms at 22 Hz and 28.5 ohms at 6 kHz. With a single-cycle sine-wave input signal our test amplifier clipped before the speaker cones audibly bottomed, although the acoustic output was visibly and audibly distorted at that point. Since this corresponded to a power input of between 1,200 and 1,300 watts at 100 Hz and 1 kHz and 420 watts at 10 kHz, it should be obvious that the CF-1 will take just about anything one is likely to put into it without much risk of damage (to itself, that is - it can put out an enormous sound level!).
Listening to the CF-1 did not in the least diminish our respect for its performance. It has a full-range, balanced sound that gives no hint of its driver configuration. Its bass capabilities are as substantial as our test results implied - the CF-1 is a speaker that can stand on its own without assistance from a subwoofer (except, as almost always, for creating a room-shaking effect from Jurassic Park or the bottom octave in an organ recording).
In our use of the CF-1, we found no idiosyncrasies, sonic or otherwise, to mar an overwhelmingly positive reaction. There are a number of very good speakers in its price range, but before making a choice it would be wise to hear the Klipsch CF-1.
