Apogee Acoustics Slant 6

A 26-inch dipole ribbon mated to a 6½-inch cone woofer in a 52½-inch slanted cabinet - the hybrid that made full-range ribbon sound seem almost practical.

Overview

Eighty pounds. Full-range ribbon loudspeakers from Apogee, the ones that built the company's reputation, are the sort of thing that needs a second set of hands and a serious talk with your lower back. The Slant 6 reportedly weighs only 80 pounds, which feels solid without the lifting problems of a full-range ribbon design. It measures 14½ inches wide, 14¼ inches deep, and 52½ inches tall, so it is a tall speaker. Still, Audio (April 1997, p.68) noted that the rounded, slanted shape makes it seem less obtrusive than those dimensions suggest.

The cabinet holds the whole argument. The Slant 6 is a hybrid: a 26-inch dipole ribbon crossing over at 1.2 kHz to a 6½-inch cone woofer, according to Audio's April 1997 profile. The ribbon does not cover the entire midrange the way the ribbon in Apogee's own Studio Grand does. That flagship was a $13,000/pair proposition, and the Slant 6 was reviewed at $2,500/pair. The trade is explicit: many of the benefits of a full-range ribbon in a less expensive and much smaller package.

Collectors chasing Apogee's ribbon sound usually want the big panels. The Slant 6 shows how much of that sound survives when you shrink the ribbon and hand the bottom three or so octaves to a cone. Audio (April 1997, p.70) found the ribbon exceptionally clean and coherent - smooth and sweet without sacrificing life or dynamic excitement - and called the speaker highly competitive in one of the most demanding price ranges in the high end. The reviewer used the Studio Grand as a reference.

The ribbon, the crossover, and what you actually hear

The 26-inch ribbon behaves like a ribbon. The reviewer heard the exceptional midrange transparency, detail, and speed above 1 kHz that characterize the best ribbons and electrostatics, with a great deal of upper-octave life and energy and no hardness. There were no significant rough spots. Treble and soundstaging stayed surprisingly stable over a relatively wide horizontal listening area, enough that two or three listeners could share the sweet spot at reasonable distances.

The caveats are worth listing. Audio (April 1997, p.70) reported a bit too much upper-midrange energy and life above 1 kHz, which sometimes pushed the soundstage slightly forward. There is also a slight rolloff in the top octave. The reviewer considered this complementary to most recordings, especially digital ones, but the upper-octave energy seemed to fall off sharply if the listener was standing or sitting too high. Your ears need to be below the top of the ribbon.

The crossover region drew scrutiny too. The cone and ribbon blended well, but the reviewer heard transition problems in the lower midrange that went beyond a touch of warmth. The blend was not as smooth as far more expensive hybrids whose larger ribbons or electrostatic panels allow crossover points low enough to be nearly unnoticeable. A truly inaudible crossover, the review noted, would have to sit at 90 Hz or lower. Much of the coloration could be minimized by adjusting toe-in, distance from the rear wall, and the three-position switch on the speaker's back that trims the relative level of woofer and ribbon.

Bass: good, not great — and that's the point

The 6½-inch woofer has a large voice coil and heavy magnet in a well-designed, solidly built reflex enclosure that produced no audible port noise, according to Audio (April 1997, p.70). Bass rolloff tapered smoothly below 35 or 40 Hz without rising to an audible peak, and real bass power reportedly kicked in only above 45 Hz. The review called the bass good, not great. The same woofer emphasized speed and dynamics over deep-bass power, which is why the ribbon/cone match works as well as it does and why the speaker proved less sensitive to room placement than many hybrids. In three different rooms the reviewer could optimize for midrange and treble without major bass sacrifices.

Percussion transients and dynamics were handled more naturally than most competitors, and bass guitar, synthesizer, piano, and bass viol all came off well. Organ notes were well defined with minimal blurring and little dynamic compression. There was a touch of warmth in the mid-bass, upper bass, and lower midrange. It was pleasant with close-miked recordings and was not accompanied by the bass overhang that smears detail on deep-bass-heavy passages.

Setup is not optional

This is a dipole with a large radiating area to the rear. Audio (April 1997, p.70) found it sensitive to placement, spacing, and toe-in, and pushed back on the conventional wisdom that dipoles are less room-sensitive than other speakers. Practical experience said otherwise. Minor changes in distance to the wall behind the speaker affected upper-octave energy and focus, and side walls and furniture could smear the soundstage. A small mirror is supplied to help set the tilt correctly for the listening position, and the manual's placement guidance is a good starting point before experimenting further.

Break-in takes roughly 50 hours of music before the speaker sounded its best, achievable with FM interstation hiss or a disc on repeat at moderate volume. Cabling is a minor variable. The speaker is not particularly cable-sensitive, though the reviewer found Symo worked best while several Audio-Quest, Discovery, and Wireworld cables performed very well, and warned off cables with trick terminators. Amplification is the bigger requirement: the Slant 6 needs far more than 50 watts per channel and an amp that is load-tolerant, with real current as well as voltage capability from solid state, or a tube amp that can deliver deep-bass power and control woofers. Biwiring is easy thanks to high-quality connectors, and spikes are included.

A naming note for buyers: Audio (April 1997, p.70) observed that Apogee was phasing out the "Centaurus" designation that appeared on the Slant 6 under review. Examples carrying either badge turn up, and the review treats them as the same speaker.

Living with one today

The Slant 6 sits in an awkward spot in the used market: too big to be a bookshelf, too small and too affordable to be a full-range Apogee. A buyer gets a 26-inch ribbon dipole crossed at 1.2 kHz, a cabinet that weighs a manageable 80 pounds, and a documented set of quirks: the listening-height sensitivity, the forward upper midrange, the 45 Hz bass floor, the placement fussiness. The reviewer's summary was that the speaker brought musical pleasure and life to a wide range of recordings, and its trade-offs were always musically natural.