Напольная акустика — Raidho Acoustics TD4.8

The TD4.8 is a Danish three-way tower from Raidho Acoustics, part of the TD Series. Raidho builds it on the same MTM concept as the TD4.2 but takes that layout further, designing the TD4.8 as a full-range speaker with no fewer than six bass drivers and two midranges, all made in-house with Tantalum Diamond cones.

Key specs that matter

Each speaker carries one Raidho TD ribbon tweeter, two 5 inch Tantalum Diamond mids plus six 6.5 inch Tantalum Diamond bass units. Crossover points sit at 400 Hz and 2.4 kHz with a stepped slope. Raidho quotes an upper limit of 50 kHz within +/-3 dB, a sensitivity of 90 dB at 2.83 V and 1 m, and a nominal impedance of 4 ohm. The enclosure itself is only 200 mm wide and 630 mm deep, while the overall footprint with feet reaches 435 mm in width, 1,780 mm in height and 670 mm in depth. Each speaker weighs 74 kg, carried by eight cone drivers and one ribbon in a single tall cabinet. Finishes are Piano Black and walnut burl veneer, with custom colours available on request.

Engineering and use context

Each Tantalum Diamond driver uses an N52 neodymium magnet with an even magnetic field and an underhung titanium voice coil. Raidho chose the underhung arrangement over the traditional overhung type because it is more linear and gives better dynamic capability, and the maker states that the result is transient response with no measurable distortion. The ribbon tweeter uses a foil 11 micron thick, which by Raidho's figure cuts mass fifty-fold against a typical dome tweeter, with its first breakup at 82 kHz. The bass section vents through a rear-firing reflex port, tuned by the maker for impulse behaviour rather than maximum output. The narrow baffle keeps the front face slim despite the tall column of eight cone drivers, and the cabinet rests on large adjustable feet with built-in decoupling that widen the stance and let the owner level the speaker on uneven floors.

Pairing

Raidho gives an amplifier power requirement of 50 to 300 W. The chosen amplification has to cope with the low nominal load, whether either a stereo design or two mono amplifiers, and the sensitivity means the lower end of that power window is usable for moderate levels. With bass extension rated down to 21 Hz by the maker, no separate subwoofer is needed in a 20 m2 room or a larger space.

Alternatives

The Raidho TD4.2 uses the same MTM concept with fewer drivers and is the smaller floorstander of the TD Series.