Полочная акустика — M&K SUR55T Tripole

The SUR55T is a surround loudspeaker from M&K Sound, the brand also known as Miller & Kreisel, and the company calls it the most compact THX Tripole solution it offers. It belongs to the 750 Series and is voice matched to every other speaker in that range. M&K notes that the original 750THX system was the very first product to carry the THX Select seal of approval.

Key specs that matter

A 5.25 inch coated glass fibre woofer and a 1.1 inch silk coated dome tweeter face forward, and each side panel carries two 3 inch mid-tweeters. The crossover point is 1.6 kHz, using Phase Focused 4th and 2nd order slopes. Nominal impedance is 4 ohm, with a minimum of 4.2 ohm. M&K gives an average in-room response of 80 Hz to 20 kHz within plus or minus 3 dB, with the output 6 dB down at 80 Hz in the near field. Sensitivity is 85 dB as an average at 2.83 V and 1 m on axis between 200 Hz and 10 kHz. Power handling is 55 W rated and 100 W long term under IEC 268-5, and M&K recommends amplifiers of 25 to 200 W. The sealed cabinet measures 25.9 x 17.8 x 22.1 cm and weighs 4.7 kg, in black vinyl.

Engineering and use context

The side drivers operate in dipole fashion while the front pair radiate directly, and M&K states that this spreads sound evenly through the listening area. The Danish-designed tweeter uses a 28 mm vented voice coil for power handling and linearity, a resonance-damped magnet system for transient control, and an integrated waveguide with a short horn load for wide dispersion. A curved metal grille and angled tweeter form a high frequency prism system aimed at both on-axis and off-axis response. The woofer has aluminium rings to reduce distortion at high levels, an extra-stiff coated fibreglass cone with M&K profile geometry, a vented pole piece and a vented voice coil for low compression. M&K says these technologies were carried over from its S150 Series.

Pairing

Within a 750 Series system the SUR55T handles the surround channels alongside the LCR750 and LCR750C at the front, while bass under the low-frequency roll-off is routed to a subwoofer. Gold plated terminals accept cable up to 5 mm or banana plugs. M&K also supplies its own proprietary interconnect cables with the 750 Series, and the crossovers are optimised for low crossover points and transient control. The 750 range carries the THX Select badge, a standard derived from the original THX programme for cinemas.

Alternatives

The M&K LCR750 is the 750 Series front speaker with two woofers and a higher sensitivity.