Apogee Stage & Mini-Grand loudspeakers Mini-Grand part 6
The best solution might be a powered version of the Mini-Grand subwoofer. This would allow the manufacturer to optimize the performance and minimize the system's overall complexity. It would surely add to the cost, but you already need two more amplifiers for the system anyway. While full-range loudspeakers with integral amplifiers, despite their many advantages, have never caught on with the public, powered subwoofers have, and they make a lot of sense.
One final concern: In the owner's manual, Apogee cautions against turning the DAX on or off while the power amps are on, as this could send a pulse through the amplifiers and loudspeakers which could damage either or both. In light of my observations above, I had to see what would happen if the DAX was turned off while the system was operating. Even if this was done unintentionally, a power failure could have serious consequences. Until just recently, I experienced brief power failures in my new house every week or two; to me, the risk of inadvertent shutdown is not academic.
To check out the possible risk, I tested both the low- and high-pass sections of the DAX separately, and began by placing another preamplifier between the DAX and the amplifier in use. This allowed me to creep up on the maximum level, watching for signs of stress in either the subwoofers or the Stages and allowing me to stop the test at any point short of unity gain. The pulse occurred at turn-off and didn't recur at turn-on. With the Stages, the maximum effect was a non-alarming "chuffing" noise. With the subwoofers, at worst the cones pulsed to a wide excursion with an audible plunk, but there was no sign that they actually bottomed out. Finally, I removed the precautionary preamp and drove both systems directly from the DAX as in normal use. There was no increase in the distress level, as the DAX was again disconnected from the line. Incidentally, for this test I used the Hafler 9500 to drive the subwoofers—I didn't want to press my luck. While this result does not mean that there'll be no risk in your system (there may be DAXes with stronger turnoff pulses than mine), it does make me breathe easier.
The present glut on the market of good, powered subwoofers means that Stage owners thinking about enhancing that loudspeaker's bass performance now have several real options. But some caution should be exercised. While mating a separate, generic subwoofer with a panel loudspeaker is not, in my opinion, quite the hair-tearing exercise it's been painted as, it can still be a tricky proposition. It can work if carefully done and if the room is right, but the blend is not always seamless. A separate subwoofer does, however, give you more placement options with which to optimize the bass without sacrificing the soundstage integrity of the upper-range loudspeakers.
One combination which I haven't yet had the opportunity to try (but hope to) is the Muse Eighteen, for which there is a "personality card" designed for the Stage. For those unfamiliar with the Muse, the "personality card" is a plug-in card which helps to optimize the high-pass or upper-range crossover to the full-range loudspeaker selected for covering the upper ranges. Since the Muse is powered, this would be a less expensive alternative overall than Apogee's own Mini-Grand. And in my experience, the Muse has a greater dynamic range than the Mini-Grand's subs. Also, the use of a single Muse will, of course, give you a mono subwoofer, in contrast to the stereo subs of the Mini-Grand. There are advantages to stereo subs, though in my opinion the advantage has more to do with the placement of two subs in different parts of the listening room—thus smoothing the bass—than with the use of stereo subs per se.
On the other hand, there's an undeniable sense of unity, both physical and sonic, to the Mini-Grand's totally integrated design. I found its overall performance stunning. I'd recommend the Stages themselves, which cover most of the frequency range, without a second thought—not surprising if you've read what I've written about them here and elsewhere. I must qualify my recommendation of the Mini-Grand subwoofers in that I suggest a moderate-sized listening room and careful matching of driving amplifiers. But when used with intelligence and careful selection of driving components, the total Mini-Grand system is an exceptional performer.—Thomas J. Norton