by Rafe Arnott
Serious speakers need serious amplification.
The Raidho Acoustics D-4.1 are what I consider serious speakers, and not just because they’re Danish (who seem serious about high fidelity), it’s because they’re big, and heavy, and need really powerful amplifiers to drive them.
Raidho says that the 140 lbs (each) D’Appolito-configured, floorstanding three-way loudspeakers nominally require more than 50 watts, but that their tests “have seen excellent results with small tube amplifiers.”
But these speakers are so big… how can a little tube amp drive them?
The same way a flea-watt, single-ended triode can pin you to the back wall of your listening space through Klipschorns: Efficient transducer/crossover designs.
The Raidhos clock in at 89 dB, the Klipschorn for comparison are rated at 105 dB.
I can hear you already: “Why do I care?”
Because a 3 db increase in speaker efficiency means you can halve the power of your amp to maintain the same volume.That’s why it’s important to understand loudspeaker efficiency ratings for amplifier pairing.
Would I recommend driving the D-4.1s with a small SET amp? Probably not if you wanted real visceral slam and listen to a lot of EDM, dub, or rock. But if you’re only into small classical quartets, or jazz you might get away with it, but you wouldn’t be hearing everything this speaker is capable of.
Regardless, I didn’t have to worry about whether the big Raidhos were getting enough power to drive them because at CES they were mated to the Aavik C-300 pre-amp, and 290 watt (into eight Ohms) P-300 power amplifier.
The C-300 features two built-in DACs (one for PCM, and one for DSD), and a dedicated moving-magnet, and moving-coil phono section is also included with the RIAA section of the pre-amp featuring a discreet, floating, balanced, ultra-low noise, bipolar input circuit. The phono stage has a set 62 dB of gain for the MC section, and loading can be configured from 50 Ohms to 10,000 Ohms.
The P-300 power amp was designed with ultra-short signal paths, a Class-A bipolar output stage, and is rated at <0.005% measurable distortion at 10W, and 1kHz into eight Ohms.
And since the D-4.1s are rated at a fairly flat six-Ohm impedance it didn’t matter what was spinning through the Nagra CDT that was in charge of delivering the music while I was in the room, the sound was incredibly fast, and tight. The big D4.1s showed off incredible cohesion, with a believable sense of timing, and speed in the bass/lower-mids due to the stiffness of their diamond-coated drivers, and obviously excellent crossover design. This is a full-throated sound with what I would describe as “pleasant colorations” in the midrange to my ears.
Prices for the D-4.1 ranges from $130,000 USD for Walnut or custom finish to $111,000 USD in Piano Black.