It turned out that this cat suffered temporary amnesia. When Pál Nagy had built my icOn 4Pro SE autoformer-based passive preamp, he'd included 4th-order/40Hz hi/lo-pass outputs on RCA. I stared right at them; if I had working x-ray vision to see the pre's business end from the chair. Herr Professor! From downstairs I quickly repossessed my Audiophonics NCx500 stereo amp with 700wpc/4Ω and switchable RCA inputs. Whilst that lacks a bass attenuator, I had volume on the Kinki/Vinshine Dazzle integrated—with remote. Rather than scale bass gain, I manipulated mains gain. At 36dB voltage gain for them vs 28dB for the sub, that was key. At 055 on the Dazzle display, I found my ideal balance. Now the remote-controlled master volume with enormous orange readout rested with the icOn SE. Filtering the Vox3 to be down 6dB/40Hz and applying thrice the bass power made an obvious difference already; and dovetailed most seamless. Still, I meant to sample higher filter hinges. But I was already tickled pink. Even at high SPL the triple-wire suspension footers truly isolated the D12 from my suspended upper wooden floor for zero discernible structural coupling. I also liked the stain Martin had applied to the cross-cut Ply to get it closer to the cherry monitors. Splendid all around. Then Herr Professor had another grey-cell incident. Didn't his hifi closet retain a small unmarked 80Hz/4th-order crossover that had survived sundry giveaways? Bingo for memory and more splendidness. Letting one ultra-damped 12" woofer per channel handle the 2nd octave rather than two small force-cancelling 5¼" was far too obvious to miss. As it happened, my initial 120Hz plans went out the window when dpd lost my gear4music shipment of the dbx box, found it a week later then returned it to seller who weirdly cancelled my order for a refund. Hint. Taken. My hifi deities had a better plan—reappear the Gradient Box II remote. Now I was in the discrete not state-variable but adjustable filter biz. One word surfaced for it:

Weightiness. Though at 120Hz I now sat a mere 40Hz higher than previously, shifting that half octave onto 12" woofers grafted on greater gravitational gumption. In its wake followed a saucier sense of scale. It's not what looking at small speakers suggests. Just so, my inner observer felt spoken to more majestically. This entailed no gain-goosing games. Same SPL as before; just a higher handover. The actual effect overshadowed the small paper difference. Whilst not on the level of the departed Vox5 packing my sub's artillery per channel to displace twice the air, it had me smile like the purring cat. Taking my Vox3 monitors to a slightly raised 20Hz compliments of an analog +3dB/20Hz shelf in my Gradient Box had morphed them into heavyweights; without their cosmetic stature. With my crossover's remote control over its low-pass volume, I could revert to running the Kinki/Vinshine Dazzle in preamp bypass. It reduces voltage gain from 36dB to 23dB. Eliminating that active gain stage clearly benefits transparency and separation. I now left the bass amp at 28dB—belly sliders can set it to five different values—then used my crossover's LF attenuator to dial back the small excess whilst retaining some headroom for late-night Fletcher-Munson compensation. Given the overall colour palette's deeper black values from the fully present bottom octave, the quicker more lucid demeanour of the integrated amp reduced to basic power-amp duty set my ideal balance between speed and mass.

The wrap. All of it was more confirmation. Active analog 2.1/2.2 filtration frees up just how we assign our frequency coverage. It's not just about unloading small speakers. It also fixes where exactly the greater cone surface of a sub's woofer/s still outweighs a smaller driver's higher speed. In my case, could an exceptionally well-damped 12er do more for 120Hz than twin 5¼"? Once spelled out like that, an answer of 'yes' is no great surprise.

One small step for my new sub, one big step for the overall effect?

Not quite the moon landing but affirmative—for a little system in the hinterlands of rural Western Eire…

Transport ⇒ DAC ⇒ preamp ⇒ crossover

Postscript. I hear gnashing teeth. "That's all very lovely but with your xover no longer being made, it's not helpful to the rest of us." True though Behringer, dbx, Sublime, Marchand and spl all offer alternatives. It's no bumper crop but not zero, either. Just so, I'm keenly aware of how skinny our choices are in this niche. Hence I've commissioned a gifted designer to add one more. If it comes off as anticipated, it could just be a lovely problem solver not just for yours truly…