Going back to the A buffet was this 3rd station. Here another autoformer passive, this time from Manchester's Pál Nagy with built-in 40Hz/4th-pass hi/lo-pass, handles remote master volume. The source is a Cen.Grand DSDAC 1.0 Deluxe with POW/I²S interface. That gets its PCM digits over HDMI from a Soundaware D300Ref USB bridge passing on SD-card files from a FiiO R7. The DAC resamples all to DSD1'024 before spitting out 6Vrms analog via XLR. My usual sound|kaos Vox3a monitor off 250W Kinki Studio monos need 20dB(!) more signal cut for equivalent SPL. They tend to sit at minus 45dB on the autoformers. The aune wanted minus 25dB or less. I actually had to reset the Zu sub's Hypex plate amp. Even at full cut it now played too loud because the incoming voltage was far higher than normal. I needed to seriously lower its input sensitivity with the Hypex filter-design software interface on my PC. Audiophile geekery. But the results were worth the small effort. Preceding the AS5 with a pure analog active high pass eliminated any <40Hz signal from even presenting at its voice coils. Given the higher SPL this 4x8m room's listening distance warrants, unloading the small monitors of higher stroke demands definitely registered. With the bottom octave covered by the 15-inch sealed sub to secure my familiar foundation, the li'l aune strutted with real sass for a show of badassery at its ask. Again, the decisive wrinkle was the fronting high pass. Whilst this one's fixed, downstairs I'd have options from 40-120Hz at 12/24dB/octave slopes to unload the AS5 even more.

Here's an open secret. If our 1st octave is firmly in place because an active room-adjusted sub of generous air coupling handles it, the colour palette's blacks saturate fully to automatically enrich the sound. This effect is hard to overstate because it renders the question of what handles the rest less critical. Given our hearing's ten octaves, claiming that the quality of the lowest one has a seniority impact on the other nine reads wholly unreasonable. But if you actually experiment not theorize, you'll come to the same conclusion. With four subwoofers in the house, I've learnt to walk this talk. Premium speakers still pull ahead of course. What shrinks is the delta of extra satisfaction they generate. Whilst they may improve the sound, that's not the same as basic gut-level satisfaction. That more or less stays in place once the low bass is managed well. Now all else eases up. It's how the properly dovetailed AS5 could rate another 'A'. On the fun/pleasure rather than audiophile stress meter, it lacked for naught. Now a sated listener forgets about fussier aspects which can otherwise take centre stage. Strange but true!

There's more. With a flexible external xover, we could well note that our sealed 15" woofer—or whatever precisely is in our sub—behaves rather more adept at 100Hz than a 5½" cone. That wouldn't be about raw reach or output but superior air coupling, dynamic crest factor, authority and ease. Without an external crossover we'd be forced to run this small cone wide open so to ~45Hz before sleeving in our sub on its own plate-amp low pass for just first-octave fill. Having precisely that fully flexible option downstairs would, I expected, add a '+' to this upstairs showing by making the AS5 act bigger still.

So let's depart this den of minor iniquity and head for my main system.