Published On: February 15, 2005
Last Updated on: March 9, 2022
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Klipsch Synergy Series SLX/SUB-10 System Reviewed

Positional the SLXs for optimal performance was easy. Watching movies the bass texture was "rich, deep, tight and quick." While the music was not quite as good as the movies, it did sound "very good through the SLXs." The Klipsch Synergy Series features a

Klipsch Synergy Series SLX/SUB-10 System Reviewed

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Since the Klipschorn® was patented 60 years ago, Klipsch loudspeakers have continued to evolve while never wavering from the four design principles the legendary Klipschorn® embodied: high efficiency with low distortion, controlled directivity, flat frequency response and wide dynamic range.

Read more Klipsch reviews here.

The cornerstone of all of this is the use of horn technology. A properly utilized horn can have a dramatic effect on the output level and frequency response, particularly of the mid and high frequencies. Without using any more amplifier power, the horn-loaded speaker can play efficiently and accurately at much higher output levels than a comparable, non-horn loaded competitor.

Unique Features
With the gray grilles on using a magnet-style attachment, the SLX mains present a trim silhouette. With them off, it is apparent that considerable thought went into the SLX's appearance. The very nice blend of form and function in the classic D'Appolito configuration gives a nice balance to the look, regardless of mounting position, and is a proven design. The sculpted ports at both ends of the speakers add to the visual impact of the grille-less SLX.

The wall mounts for the SLX look basic: relatively thin, light, shorter than the speaker, with a large tab at each end. How the SLX attaches to, works while on, and removes from the bracket is going to have a lot of competing product designers experiencing the ol' palm slap to the forehead, "Why didn't I think of that?" The rear of the SLX has one slot at each end. Simply line the slots up with the tabs or mounting posts and push. A click will tell you the Positive Lock Attachment• system has locked the speaker into the bracket. While there, the speaker can be pivoted 30 degrees to allow you to "toe-in". Removing the SLX requires only a push of a button and a light pull. As a user-friendly finishing touch, wire management is also part of the design.

I described the speaker configuration on the SLX as a D'Appolito design. Insofar as the two 4.5-inch drivers are mounted on each end of the SLX with the tweeter mounted in the center of the speaker, the design fits my description. However, Klipsch has designed the speaker to make it perform differently in some respects than the D'Appolito design is known for. Normally, speakers designed this way and used vertically exhibit broad horizontal dispersion of the high frequencies. At the same time, vertical dispersion is controlled between the two larger drivers. This could potentially create sonic differences when the speakers are used differently, say if the mains are used vertically, and the center (in more than a 2.1 system) is used horizontally. Klipsch has designed a round Tractrix® horn around the tweeter, which frees the tweeter from the acoustic boundaries normally produced by the drivers.

The SUB-10 subwoofer is not significantly different in appearance to a multitude of other woofers. It is of about medium size when compared to other cabinets using a 10-inch driver. The top edge and corners are rounded in nicely. The feet are an "outrigger" design, extending a little beyond the cabinet's width. On the rear are connections for high-level (speaker wire), or line-level (RCA) inputs. There is a master power switch and toggle for setting the woofer to be always on or to auto, plus a phase toggle. Missing from the SUB-10 (and most other subs in this price range) is a bypass for the internal crossover. Many modern surround sound receivers incorporate an adjustable crossover in the receiver itself, and on most of these receivers the internal crossover cannot be bypassed on the sub pre-out. I would love to see this conflict resolved.

Read much more on Page 2


Installation/Setup/Ease of Use
I set up this system as Klipsch feels it is likely to be used in most homes. The SLX speakers were mounted on Sanus FF1S stands with the tweeter at ear level. The SLXs were placed approximately nine feet apart, to each end of an entertainment center with six-foot-tall cabinets on each end. My seat was about 12 feet from the center. I placed the woofer on the same wall as the SLX speakers, which were connected to a Denon AVR-3805 surround sound receiver. Kimber Cable PR-4 speaker wire was used.

Read more Klipsch reviews here.

After allowing several days of "break in" time, I noticed the speakers were highly directional; so much so that a minor change in the toe-in made as much difference as changing the volume of that speaker by several decibels! On the negative side, the sweet spot is going to be very limited in a 2.1 system. On the positive side, the SLXs were not affected substantially by room boundaries, and it is very easy to get precise localization from the soundtrack.

Positioning the SLXs for optimal performance was easy. After making small adjustments to the amount of toe-in, I got a very clear, focused image with nice dimensions. This level of performance was good for an area wide enough for two people. As noticeable as the speaker's directionality was the very convincing center channel effect obtained from just the right and left speakers.

Regarding the "Tapered Array", I heard clear, open, heavy when necessary, but never boomy vocals, which I believe is a direct result of this design feature. Basically, both 4.5-inch drivers work the same at the lowest frequencies. As the pitch gets higher, one plays only into the midrange, while the other continues to play right up to the 3,000 Hz crossover frequency of the horn-loaded tweeter. This well-executed crossover arrangement provides bass when needed, but does not unnaturally "color" difficult and dynamic dialog with overly bass-heavy voices. True to Klipsch's four design principles, the SLXs did not require the Denon receiver to be cranked on in order to achieve very impressive volume levels without apparent strain, and, most notably, with less compression than many other speakers using small drivers and limited cabinet space.

The SUB-10 took very little adjustment to blend perfectly with the SLX mains. A large part of this has to do with the SLX speakers being tuned lower than many speakers of their size. Klipsch is able to accomplish this with the use of "Folded Port Extensions". I had this technique explained to me, and my eyes glazed over much like yours would if I tried the same. Suffice to say, this is an ingenious porting system, and it works. I did pull the woofer about 18 inches from the wall to get the texture of bass I like: rich, deep, tight and quick. It lost very little output doing this, and got rid of the boom, lack of detail, and overhang first heard with the sub closer to the wall. I tried all of my favorite "poser exposer" low frequency effects from different movies. Without being just plain abusive, I could not seriously tax the SUB-10. When the wall of Helms Deep on The Lord of the Rings: The Two Towers Extended Edition is breached with explosives, the dynamics surprised me - it was one of those moments like turning on the stereo after it had been turned off with the volume way up.

Final Take
Used as Klipsch predicts their target demographic will use the SLX/SUB-10 system, I think it is a formidable combo at its price point. As much as I enjoyed this system on movies and TV, I was not as impressed with just music. Do not misunderstand me! Music did sound very good through the SLXs, and only an audiophile is likely to complain. I feel their design particularly suits them for use with video. In Klipsch's defense, to allow for consistent performance whether used horizontally or vertically, and to have a best-in-class performer for use with video soundtracks, certain design parameters had to be adhered to. Better to have an exceptional performer for a specific use, than to have a merely adequate performer for a variety of applications. Would I own them? You betcha!

Read more top performing bookshelf speaker reviews here from brands like Polk Audio, Def Tech, Golden Ear, Paradigm and many others.

Klipsch Synergy Series
SLX Left/Center/Right Speaker
(1) 1" aluminum dome K-138 neodymium tweeter
(2) 4.5" neodymium magnetically shielded woofers
Frequency response - 82 Hz to 23 KHz +/- 3db
Sensitivity - 95db @ 2.83 volts/1 meter
Power handling - 100 watts max continuous
(400 watts peak)
Weight - 9.5 lbs (without bracket)
10 lbs (with bracket)
MSRP - $349 each

Down-firing ported bass reflex
(1) 10" active driver
Frequency response - 28 Hz to 120 Hz +/- 3 db Built-in 200 WRMS amplifier @ 1% THD
Dynamic power - 400 watts
Weight - 37 lbs
MSRP - $399

Sanus FF1S Stands - $159/pair

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