Apogee Centaurus Home Theater Speaker System

By Bill Cruce

Table of Contents


Slant 8 and LCR in position

Front Channels
Rear Channel
Center Channel
Field Repairs


For five years I listened to movie sound with Krell-powered Apogee Scintilla ribbon speakers in front and Adcom-powered Sequerra dynamic speakers in back, but no center speaker. Then I began a series of experiments to explore the variants of center channel sound. My previous attempts to find a center channel speaker which would match the Scintillas in timbre had been such dismal failures that I always listened in "phantom mode." In the summer of 1994, Tony Schuman at Apogee suggested I try their Architectural Series center channel Speaker. This speaker matched the Scintillas better than anything I had heard, but it was still far from the solution I sought. Next, at the suggestion of Apogee's Jason Bloom, a newer all-Apogee system was substituted for the Scintillas and Sequerras. This combination of Centaurus hybrids (ribbon & dynamic) was not only a better match with the timbre of the center channel speaker, but proved to be a dynamite system for both music and movies. The Slant 8, used on the front left and right retains the transparency, speed, and imaging characteristics of the Scintilla yet has a much more solid sounding bass, certainly better matched to my small room. The Columns, used on the left and right rear, were an ideal timbre match to the Slant 8's. They also can be used in the THX-favored dipole arrangement.

But the Apogee Architectural center speaker still sounded too boxy. Finally, at Sarah Bloom's suggestion, I replaced it with their new Ribbon LCR speaker and that proved a winner, closely matching the other Apogee speakers yet being small enough to fit on top of my video monitor (a 40" Mitsubishi 40503). For a time I had difficulty listening to a center channel because the sound is tightly focused above or below the monitor instead of floating in space at its center. But movie surround-sound soundtracks, which are mixed with a center channel in mind, generally sound better over a solid center channel, while stereo soundtracks generally do not. At last I have the proper analytical tools to explore these issues.

Front Channels

The Centaurus series of speakers depart from the classic Apogee design which uses a tall ribbon midrange/tweeter flanked by a flat-panel woofer. The flat-panel woofer consists of current carrying traces embedded in a membrane sheet, backed by a swiss-cheese like magnetic plate. The Centaurus speakers are a hybrid design, using a dynamic cone woofer instead of a flat-panel woofer. This design is traditionally said to trade the speed and dynamics of a membrane woofer for the more room-friendly dynamic cone woofer, though that doesn't apply in this case. When I bought my Scintillas, I had a very large (20' x 40') room which gave them plenty of room to breathe. The Scintillas need to be positioned quite far from any wall to avoid boundary effects. In my new quarters (8' x 14') the Scintillas lost some of their remarkable transparency and no matter what I did, their bass had a little too much boom (or is that bloom?). The Slant 8's are a marvelous match for this room, though the Slant 6's might have worked as well.

Apogee Slant 8 The Slant 8 is a black monolith with a 60" x 16" face having a 40" ribbon located vertically along the inner edge. (One is encouraged to experiment with positioning the ribbons on the outer edges by switching L and R speakers.) An 8" Danish VIFA woofer is positioned 39" from the floor but hidden behind a grille cloth that covers the entire front face (and the grille cloth is not easily removed without a special service tool). The woofer's slot-loaded box is built in a tapered configuration that looks like a black concrete support for the front panel. The Slant 8 feels like it is made of solid granite, both in weight and in lack of resonance when you rap the box with your knuckles. This is the most rigid speaker structure I have ever encountered.

At the rear base of the Slant 8 are two pairs of hefty gold plated "5-way" binding posts that accept thick spade lugs or banana plugs. The speaker can be biwired by removing the supplied jumper brackets. A toggle switch adjusts woofer output up or down by 2 dB and alters its "Q" to higher or lower, respectively. I used the Slant 8's biwired with Straightwire Duet speaker cable and with the "Q" switch in its high position, but this is a matter of personal preference and room characteristics. The speaker comes with a set of four spikes and matching screw-in sockets in the base. Once spiked and positioned, this 120-pound mother doesn't want to be moved.

Rear Channel

Apogee Column The Centaurus Column is the delicate female cousin of the Slant 8. It is a 61" -tall, 9" x 9" cross section, black, cloth-covered column. The cloth covers the speakers as a kind of sock and is not easily removed. Speaker wires are attached to the bottom of their base, where there is only one pair of hefty "5-way" binding posts. (No biwiring option, but it does have the same "Q" switch as the Slant 8.) The wires are dressed out through a slot in the rear of the base. At 76 pounds, it is not as difficult to move as the Slant 8, but, once positioned, it isn't easy to change the speaker connections. The "oblique-dipole" configuration of the ribbon in the Columns has both a forward-firing and a side-firing direction. Because the Columns do not vent to the rear, they can be placed up against a wall, which is how I positioned them as my rear speakers. However they work equally well as front speakers, placed either against the wall or positioned out into the room like a traditional Apogee. The recommended orientation as front speakers is with the side-firing face pointing inwards, toward the other speaker. As rear speakers I reversed them so that the front face fired towards me and the side face fired towards the front of the room. This created a semi-dipole effect, producing just the right amount of diffuse and direct sound from the rear channels. They are supplied with spikes and matching screw-in sockets in the base.

Center Channel

Apogee Architectural center The first Apogee center speaker I auditioned, simply called the Center Speaker, came from its Architectural Series, designed to be built into walls. It employs a 16" dipole ribbon in a D'Appolito configuration with a pair of 6.5" slot-loaded woofers. The ribbon has a housing to direct the rear wave back to the front, making the speaker easily positioned in a wall or above or below a monitor. In fact, the imposing 60 lb weight and 20" x 24" x 10" dimensions practically dictate it being positioned beneath a monitor or projection screen. This speaker, like the other Apogee designs, has a solid, non-resonant box. There is a pair of solid metal "5-way" binding posts on the rear. The front grille cloth is easily removed for access to the speaker elements. The speakers come supplied with a pair of mounting brackets for the bottom which accepts screw-in mounting spikes. Since I found this speaker to sound boxy in comparison with the rest of the Apogee system I won't say anything else about it. In fact, it is no longer in production.

Apogee LCR center The Ribbon LCR (Left/Center/Right) is the second Apogee center speaker I tried. It has Apogee's new corrugated 4" ribbon mounted in the middle flanked by a pair of 6.5" port-loaded dynamic woofers. The ribbon is built into a square mounting box and can be easily unscrewed from the speaker front and rotated 90 degrees. In one position you have a classic D'Appolito configuration, which can be mounted horizontally above or below the monitor or screen. In the other position, it can be positioned vertically to the sides of the monitor or screen (e.g., for the front left and right channels). The back of the speaker houses two pairs of gold-plated metal "5-way" binding posts. As with the Slant8's, a supplied strapping piece can be removed for biwiring or biamping. The woofer port is also located in the rear and a foam plug is supplied if you wish to stuff the port and reduce bass emphasis (for example to blend better with a subwoofer). While this speaker has a wood grain finish instead of the speckled concrete appearance of the other Apogees under review, it is still a deep black color. It is the smallest and lowest weight of these speakers. But what a little performer! LCRs in two positions


It might be argued that the Slant 8's, with respectable output well below 30 Hz, are not in need of a subwoofer. But this is one place where a sound system meant for video differs from one used simply for music. The thunderous low frequency special effects found on movie soundtracks can be better handled by a subwoofer. Ironically, I have found that mating a subwoofer to speakers that are deficient in bass above 40 Hz is more difficult. It is especially hard to get a blend that doesn't harm the music. Having a subwoofer on the Slant 8's gives better control over the bottom octave of the audible spectrum (20-40 Hz). Likewise, stereo subs --arguments about our low-frequency localization abilities aside-- offer additional control over this region. (See the separate review of the M&K MX-200 subwoofers for more discussion of this topic.) By manipulating subwoofer position as well as crossover characteristics, you can get smoother response in the bottom end. I have used a pair of M&K MX-200 subwoofers, each having a self-contained 200 watt amplifier driving a push-pull pair of 12 inch cones (one faces downward, the other forward). They are mostly run in a parallel stereo configuration with the Slant 8's. That is I run the full bandwidth of each channel of the preamp or surround processor output into the Slant 8's while running a split of that signal into the MX-200's with their internal filter set at about 45 Hz (roll-off at 18 dB/octave).

I have also run the MX-200's from the subwoofer outputs of several surround processors. The most flexible processor in this respect is the Lexicon CP-3+ which allows independent setting of the crossover on the main and sub channels. Because of the independent control it gives me over the low frequencies, I am currently using a separate electronic crossover --the Bryston 10B SUB-- on the main front left and right channels. This, like all Bryston electronics, is incredibly well-built and neutral sounding. (See the separate review of the Bryston 10B crossover.) It has separate controls for rollover frequency (12 steps from 40 to 500 Hz) and slope (6, 12, 18 dB/octave) on both the low- and high-pass filters. For the current configuration I set each MX-200 internal filter at its maximum point, 200 Hz (above 125 Hz this filter has a 36 dB/octave slope) and use the Bryston low-pass output set at 50 Hz and 18 dB/octave. I have run the Slant 8's at both full bandwidth and with the Bryston's high-pass filter in place. (I currently prefer the high-pass filter for the Slant 8's to be set at 100 Hz and 12 dB/octave).

Field Repairs

When you buy speakers you don't normally think about how easy (or not) they may be to get repaired. Luckily speakers as rugged as Apogees rarely need repair. However, due to unfortunate accidents, I had two opportunities to perform field repairs on the Apogee Slant 8s. I was pleased to discover that the repairs were actually quite easy to carry out; pleased because shipping speakers the size of Slant 8s back to the factory wouldn't have been easy.

Upon unpacking and setting up the Slant 8s, I discovered that the woofer in one had been damaged in shipping. Apogee promptly shipped me a replacement woofer along with detailed instructions and a special tool (a large flattened crowbar) for prying loose the grille cloth. It was simple to pop the grille, unscrew the woofer from the front, disconnect the wires, and insert the replacement.

After some months of auditioning the Slant 8s, I made the mistake of playing a 0 dB digital test tone through the left speaker. Smoke came out of the ribbon midrange-tweeter before I could shut down the signal. After that the ribbon sagged physically and produced rattles and buzzes. It was with a saddened heart that I called Apogee, but they assured me that the ribbon replacement kit they would ship out was easy for the user to install. I am happy to report that it was. The instructions are well-written and detailed. The kit comes with everything you need including a jig and lead weights for tensioning the new ribbon. Anyone with a modicom of mechanical skill can perform the procedure.

I must compliment Apogee on how thoroughly well prepared are the field repair kits. I saw a side of a speaker which most audiophiles, even reviewers, rarely do. These speakers, sophisticated though they be, are obviously designed to make assembly simple. This should translate into keeping down costs and increasing reliability. It also makes field repair simple, whether by the user or the dealer.


Apogee Scintillas are infamous for their incredibly low, amplifier-melting impedance (smoothly hovering between 0.5 and 1.0 ohm in their best sounding configuration). One of the first things an old Apogee nut like myself notices about the new line of speakers is that ultra low impedances have been banished (now typically 4-6 ohms). This means a much wider variety of amplifiers can be tried with the speakers, including tubed amps. Since I had to give up my tubed Audio Research D-90 when I went to the Scintillas, the relatively high impedance of the current Apogees is seen by me as a blessing. I am drooling at the possibility of auditioning some tubed amps on the Centaurus hybrids. But, for now, I have been content to try a variety of solid state beasties. My Krell KSA-100 sounded marvelous, as did the Mondial Aragon 4004's, which are said by many to mate particularly well with the Slant 8's. But I have finally settled on the superb Classe' CA-200 (recommended to me by a local dealer, Bob Ashe of the Golden Gramophone in Akron, Ohio). It has the solid, current-pumping, smooth musicality of a classic Krell but with far less of the space-heater characteristics I have come to abhor.

In my initial comparisons of the Scintillas and the Slant 8's, using the Krell KSA-100, I listened for controlled yet lively sound of a plucked string bass. My favorite recording for this is Norman Blake on vinyl (Flying Fish HDS-701). Indeed it was the Scintillas' performance on this recording which first endeared them to me. The sound of the plucked bass was coherent, with a deep bass naturalness. Wire brushes, cymbals, and triangles also sounded natural. The Slant 8's bettered the Scintillas in every test I could throw at them from this vinyl treasure. They had more bass punch without boominess.

I also listened to the CD of Amanda McBroom and Lincoln Mayorga's Growing Up in Hollywood Town (Sheffield Lab CD-13), especially track 3, "The Rose." (I have auditioned this much-loved recording on a variety of systems since it was first released on a direct-to-disk vinyl many years ago.) In addition to the well controlled bass, there was an incredible depth and width to the soundstage. Subtle details of triangle, wire brush, breathing, and small room noises, evident on the Slant 8's, were lost on the Scintillas.

I have lived with this Apogee system for more than two years as a variety of amps and surround sound decoders have visted chez Cruce. I've listened to vinyl containing many types of acoustic music --classical symphonic, classical chamber group, jazz, blues, country, and folk. From CD, I use all of the above plus a variety of modern and popular music, including everything from Pink Floyd, the Rolling Stones, and U2 to Enya, Enigma, Sara Mclaughlin, and Hootie and the Blowfish. This system can do justice to such extremely different sounds as acoustic jazz (e.g., Jazz at the Pawnshop [Proprius-Audio Source CDP 7778/9]), classical full-symphonic (e.g., Maazel & The Cleveland Orchestra doing Prokofiev's Romeo & Juliet [London 417510-2] or Fedoseev and The Moscow Radio Symphony Orchestra doing Stravinsky's Rite of Spring [MGM MCD 10029]), and the movie laserdiscs of Jurrassic Park [MCA/Universal 41830] and The Last of the Mohicans [Fox Video 1986-85] (a particularly revealing soundtrack). For music only, I sometimes switch off the subs, though, when adjusted correctly, they are unobtrusive on music and explode into action on video soundtracks.

Like music, video soundtracks deserve the best audio system that you can can afford to play them on. The Last of the Mohicans, my favorite test for subtle, detailed sounds, shows up differences in decoders, amps, speakers, and cables. This is true on the front channels as well as the rear. The ambiance created by the echoes and reverberations of gun/cannon fire in the forest can sound different with changes in the audio system. (Listen to the opening hunt scene for the full range, from crackling twigs to a full musket blast in the face, followed by echo.) In chapter 4, 9.23-9.39, there is a dog faintly barking in the distant background. I first heard this most distinctly on a Fosgate Four in 70mm mode. It is simply lost on many surround sound processors and speaker systems. After careful setup of the Apogee Columns in the rear with appropriate tweaking of the Sony TA-E2000ESD processor my system passes this test as well. (See the discussion of digital parametric equalization in the review of the Sony TA-E2000ESD processor.)

Nothing beats The Surround Spectacular CD [Delos DE 3179] for the straightforward test tones and pink noise essential for setting up a surround sound system. Using its various pans across the front two channels and three channels, as well as full surround pans that employ all four channels (the rear being, of course, a single mono channel in Dolby Pro Logic), I have done some fine-tuning of the rear and center channel (both by ear and with a sound level meter and spectrum analyzer). My favorite surround sound processor, the all digital Sony TA-E2000ESD, can insert digital domain equalization in any channel. But it also lacks buffers on the center and rear channel outputs which causes a slight high frequency rolloff in these channels with the relatively long (5 meter) cables I use. The Apogee Ribbon LCR speaker sounds remarkably close in timbre to the Slant 8's, more so than any other speaker I have auditioned. It is so similar, in fact, that the slight roll off of the extreme highs in the center channel of the Sony TA-E2000ESD is readily evident with the Delos disk. Judicious application of digital parametric equalization to the center channel (+3 dB, 6.85 kHz, Q 0.7) has remedied this. After doing extensive comparisons with a Fosgate Four surround sound processor, I found that a moderate high frequency boost (+6 dB, 10 kHz, Q 0.7) overcomes some of the dullness of Pro Logic's standard surround channel response which is down 6 dB at 10 kHz (as well as some additional contribution from the long cables used with the Sony TA-E2000ESD) and makes my system sound much more like the famous Fosgate 70mm mode. Pans of sound between any combination of channels are now incredibly smooth. The Delos torture test (track 34, which sweeps a descending band of noise from 13 kHz to 100 Hz in a position halfway between the center and the left or right front speaker) is now rock stable except for slight head diffraction effects. Care in correct phasing of the speakers pays off here too.

Positioning of the center speaker with respect to the forward/backward location of the front left and right speakers also deserves careful attention. Much has been written of the importance of positioning the center speaker on the arc of a circle containing the left and right speakers on the circumference and the listener at the center. That is, conventionally, the center speaker should be the same distance from the listener as are the main stereo speakers. This usually means placing it slightly behind a line drawn between the left and right speakers. However, some listeners have found that the center speaker sounds even better if placed farther back. Using the Lexicon CP-3+, which has a variable delay for the center as well as the rear speakers, I found that a 3 to 4 millisecond delay was optimal. This translates into a position about three to four feet behind the main speakers, if no delay is used! Since most surround processors, the Sony TA-E2000ESD included, do not have the ability to adjust center channel delay, I now have the Ribbon LCR positioned three feet back. As it turns out this places it on top of my Mitsubishi monitor. Since the LCR is well shielded, this doesn't affect the monitor. The Slant 8's, however, are not shielded --quite the opposite. They generate such an intense magnetic field that they must be a minimum of three feet from the Mitsubishi, and their exact position is critical to aim the lobes of the magnetic field away from the TV. (Listeners who need to place their speakers closer to a direct-view monitor should be aware that the Apogee Slant 6's, but not the Slant 8's, can be ordered with magnetic shielding.) Thus, in my small room, when the all the constraints of speaker positioning are taken into account (distance from rear and side walls, from each other, from listener, from monitor) there is only one perfect spot for the L & R speakers. And they sound marvelous there.

The center channel speaker, the Apogee Ribbon LCR, now blends so well with the Slant 8's that I can switch it in or out and barely detect the difference if I am sitting in the sweet spot for a phantom center image. This is especially true on movie soundtracks with center dialogue or music vocals which have been mixed with a center channel in place. Stereo music tracks are not good tests for a center channel. Well recorded stereo, when it includes the ambiance of a natural acoustic space, can sound flat and lifeless if a center channel is switched in, even if out-of-phase ambiance is sent to the rear channels. While some stereo music sounds better with Dolby Pro Logic switched in, this really has to be determined on a case-by-case basis.


One problem with putting together a single system which sounds good for both music and video is that many of the best and most musical speakers are simply too large. Fitting a third one into the center channel means blocking the video image. Some of the best minds in audio are hard at work on this problem, so it may be that, in the future, we will have a wide choice of quality mini-monitors which will fit beneath the viewing screen but have no compromise in sound. Indeed, for those on a modest budget, the incredible Linaeum/Radio Shack LX-5 speakers (around $100 each on sale) offer the opportunity to have near state-of-the-art sound from about 500 Hz upwards (though of limited dynamic range) and they will easily fit anywhere you care to place them in a room.

For now, loving the sound of big ribbon speakers as I do, the combination of the Apogee Ribbon LCR and the Slant 8's works remarkably well for the front. The Columns are a full-bandwidth rear channel pair that can be easily positioned in most rooms (either against the wall or not). The M&K subs provide heft and substance in the bottom octave without boom or smear. It is a system of uncompromising sound that is so good it is revealing of subtleties in every component in front of it.


The author wishes to thank John and Bob Ashe of The Golden Gramophone in Fairlawn, Ohio for introducing him to High End sound and for letting him audition many reference sound systems over the years. He also wishes to thank Hi-Tech Hi-Fi of Lyndhurst, Ohio and New Image Electronics of Cleveland Heights, Ohio for letting him audition several sound systems in their showroom. He is especially indebted to his friend Mike Marks for many hours of listening, comparing, switching, and listening again; Mike's Fosgate/Magnepan system has been a useful tool for comparison. The author is especially indebted to CyberTheater co-director, Greg Rogers, for calling his attention to the Sony TA-E2000ESD processor.

Apogee Product Information

Sadly, Apogee Speakers are no longer made and replacement parts are difficult to find. I have assembled a page with additional information (09/00).
Go here

Manufacturer's Specifications:

Model: Centaurus Slant 8 Centaurus Columns Architectural Series Center Channel Centaurus Ribbon LCR
Components: 40" dipole ribbon, 8" woofer 26" oblique-dipole ribbon, 6.5" woofer 16" dipole ribbon, dual 6.5" woofers 4" corrugated ribbon, dual 6.5"woofers
Weight: 120 lbs. each 76 lbs. each 60 lbs. each 40 lbs. each
Dimensions: 59.5"H x 17.1"W x 17.1"D 60.0"H x 13.0"W x 9.8"D 20.0"H x 23.5"W x 9.5"D 24.0"H x 9.5"W x 11.5"D
Impedance: 6 ohms nominal (4 ohms minimum) 6 ohms nominal (4 ohms minimum) 6 ohms nominal (4 ohms minimum) 6 ohms nominal (4 ohms minimum)
Frequency Response, Specified: 26Hz - 20kHz 35Hz - 20kHz 60Hz - 20kHz 45Hz - 25kHz
Serial Numbers: 1098, 1099 1254, 1255 4630 1159
Suggested Retail Prices: $3995 pair $1795 pair $1195 each (no longer available) $900 each

An earlier version of this review appeared in issue #105 of The Absolute Sound. The text, with minor revisions and updates, is reproduced here by permission of Pearson Publishing. Issue #105 of The Absolute Sound includes other reviews by Greg Rogers and Bill Cruce (co-producers/co-directors) of CyberTheater™.

-- end of Apogee Centaurus Speaker Review--

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