Download 6Moons test report. July 2013 (PDF). - German Physiks

On natural tone multi-polar speakers do things differently and arguably
far better than the dominant (barbarian?) hordes of conventional
radiators. From a Shahinian Obelisk to FJ's Ohm of yore, to Dick
Olsher's bygone mini cube with upfiring mid/woofer and front-firing
tweeter, to the already mentioned Duevels and Morrisons and my
Boenicke B10 at right and even the Bose 901, there have been
numerous attempts to energize or 'activate' our playback venues more
evenly as happens during a performance. Planars with out-of-phase
front/back radiation suffer lateral figure-8 phase cancellation. They aren't
omnis to the same degree (and a more appropriate term in the first place
would be polyradials, since true omnis would have to include floor and
ceiling radiation like a pulsating sphere suspended in free space, which
no speaker does). The DDD radiates in-phase like a lighthouse would
disperse light, without its rotating flare. It radiates directly without first
reflecting off its own structure like speakers with dispersion lenses. The
net result is tonal fullness, linked to in-room energy density, linked to
perceived loudness. You can play the HRS-120 at low volume without
diluting this fullness, which arises from more complete room fill.
Meanwhile high volumes scale up more intensely. They load up the
entire space with sound pressure increases in (nearly) all directions.
This would seem to be a more effective less lossy conversion of
amplifier power into loudness, going beyond the basic voltage efficiency
equation where 'x' input voltage nets 'y' decibels at 1 meter on axis.
On that count I was simply tickled that for my civilized
purposes the 10wpc SIT1 didn't run out of steam,
though they did seem to run extra hot. Devotees of big
symphonica or music with punishing bass transients, will
most certainly want more headroom and grunt. I simply
think that stuffing an 80-piece orchestra into a space
barely sufficient to properly hold a string quintet is a
ludicrous proposition. It's as far removed from 'realistic'
or 'believable' as one could get. I thus do precious little
of such extreme stuffing. Back to amplifier matching, I
also tried Norma Audio's 2MHz IPA 140 integrated. This
again was a bit too soft, even in direct mode with my
Nagra, which quickens its performance. Resolution
Audio's Cantata C50 mated slightly better, but not nearly
as well as the Job 225. Whilst the Norma had the
highest bandwidth for presumably fastest rise
times and the most raw power, those factors weren't
decisive. What about the Job inked the deal I don't
know. I can't make an educated guess about ideal specs
an amplifier shopper for this speaker should cross off.
What I can say is that this $1.495 amp very nicely offset
some of the HRS-120's steep €11.500 satin-finish
sticker.