An International Project
The Klipsch P-39F has drawn on engineering, design and manufacturing resources from all aver the world. In addi- tion to our formidable team in the USA, we have used European industrial designers, British theoretical physicists and manufacturing and production specialists from China. The focal point of these resources is our birthplace, Hope, Arkansas, where, under the vigilant eyes of the most skilled manufacturers of horn loudspeakers anywhere in the world, your P-39F was built, tested, measured, evaluated in rigorous listening tests, and finally shipped.
The P-39F is the culmination of over 60 years of research and engineering advancements, having been designed with the most advanced computer aided design (CAD) tools available, rigorously evaluated using our own in-house proprietary software, built to the most stringent quality standards and voiced by a panel of our most experienced listeners. No Klipsch loudspeaker has ever had more care and attention to every detail lavished on it than your P-39F.
Although building one pair of matched loudspeakers is relatively straightforward, building hundreds of matched loudspeakers is challenging. Measurements play an important role in analyzing loudspeaker characteristics, but the human ear is the ultimate test gear for evaluating its reproduction quality . At Klipsch, every loudspeaker de- sign is strictly evaluated using listening tests designed to expose even the very smallest weakness. All final voic- ing is performed under blind conditions, using trained listeners and standard audio sound tracks selected based on their particular area of auditory excellence. All information is tabulated and reported back to the designer for analysis. In almost all cases, Klipsch products are evaluated against similarly priced competitive models. It is only in this manner that Klipsch can truly rely on the quality of feedback received, eliminating skewed data that may result due to influences caused by price, brand recognition, or visual appeal.
Design
The P-39F is a 3.5-way bass-reflex full range loudspeaker with high sensitivity and extremely low distortion. The five drivers of the P-39F comprise three 9” woofers, an advanced 4.5-inch horn-loaded compression midrange driver, and a .75-inch titanium horn loaded compression dome tweeter. Each driver was designed by the Klipsch Engineering team and optimized for superior performance within each transducers bandwidth. Accurate driver design minimizes the need for driver corrections in the crossover network. Thus, the crossover is a straightfor- ward design, with extremely high-quality components ensuring minimal insertion loss. By presenting a simple load to the amplifier, overall system performance is enhanced, a phenomenon rarely found with conventional designs. Each com- ponent used in the crossover, from the air core inductors to the polypropylene capacitors, has been selected to provide an undistorted transition between transducers. The superior components used in the P-39F are complemented by the unique horn and enclosure design and highlighted by the elemental perfor- mance of the industrial design. The massive laminated MDF enclosure is based on a curved non-parallel wall structure for minimal resonance. Both the tweeter and midrange compression drivers are integrated into a common molded two- element horn optimized for bandwidth, clarity, and efficiency.
Bass Drivers
With 18-mm peak to peak linear excursion, and three 9-inch cones, the P-39F is capable of remarkably clean dynamic response down to a -3 dB point of 39 Hz.
The woofer utilizes a low mass hybrid Aluminum/Rohacell®/Kevlar® cone with an over hung voice coil. Even under massive dynamic demand, the driver retains linearity and low distortion. A three-part high intensity neodymium magnet is used with a main magnet, plus rear and forward magnets to ensure linearity, reduce stray magnetic energy and provide intense field strength in the voice coil gap. Dual Faraday rings on the pole piece minimize unwanted inductance, enhance heat dissipation and minimize dynamic compression.
The metal cone of the woofer is damped with a composite Rohacel and Kevlar layers which minimizes ringing and maintains low mass, eliminating breakup and other distortion products. As is the case with
the midrange driver, the surround uses a flat-sided shape that keeps surround-produced output to a minimum and preserves phase response. The cast aluminum frame assures
maximum heat transfer without any reflection of the back wave of the driver that would otherwise alter the sound. An inverted half-roll low density foam rubber surround com- pletes the clean appearance.
The woofers see differing pass bands. This preserves consistent dispersion through the critical woofer to midrange transition region and has a positive impact on off-axis performance and stereo imaging. This upper woofer covers the entire range from 30 Hz
to 500 Hz, where it crosses over to the midrange driver, while the two lower woofers cover only the low and mid-bass. This “tapered-array” design delivers full bass impact, plus a graceful transition between driver groups in both tonal accuracy and dispersion.
Midrange - “The midrange is where we live.” Paul W. Klipsch
The inverted dome midrange driver operates from 500 Hz to 3.5 kHz and is a unique design, not found on any previous Klipsch product.
The driver sensitivity of 106 dB allows minimal excursion at normal playback volume. As cone excursion reduces, so does distortion. The 4.5-inch aluminum dome is driven by 3 high temperature N35H neodymium magnets, ensuring linearity under a range of listening volumes. The pole piece is topped by a copper cap to minimize unwanted inductive components. The surround has half the density of the material
typically used and thus offers reduced mass. Unlike most designs, this midrange driver delivers much more out- put from the dome and less from the surround. As a surround is always in motion and always changing shape, output from its surface is high in distortion—minimizing surround surface area is another means to reducing
overall distortion.
The midrange unit is housed in its own magnetically-shielded sealed enclosure, which isolates the driver from acoustic energy generated by the woofers. Every effort has been made to ensure great accuracy, as well as long-term durability from this unique driver.
