MediaTech Ltd. came to High End 2010 with a new model of Hi-Fi loudspeaker system. Under the brand Concave was developed active speaker system, fulfilling the uncompromising requirements for quality, functionality and design.

Audio Resolution's model Concave represents 2 - Way Active speaker system that meets the highest requirements of High End applications through special hand-made loudspeaker baffle, electronics and carefully selected D-A converter. The solid active principles with modern power amplifier ensure a dynamic sound and a true music experience. Attractive design brings powerful visual experience and excellent sound; this is a short description of the Audio Resolution model Concave produced in Slovakia.

 
Characteristics

Audio Resolution Concave is a two way active loudspeaker system. A simple shape, sophisticated cabinet and face masks design, the use of sophisticated electronics and a latest generation of loudspeaker transducers provide the most demanding requirements of current High-End applications. Thanks to the unique digital to analog converter technology our speaker sound system neutral. Compact, transparent and dynamic sound, are just some terms that usually characterise a good speaker sound system. Concave speaker system will tell you more detail and express the true depth of quality. It will introduce the third dimension in sound reproduction.

Baffle, enclosure The Baffle is made from 21 mm thick MDF boards reinforced with internal bracements. Effective volume for both woofers is approx. 25 litres. The rest of the Baffle’s volume is used for placement electronics module. The Concave is finished with combination of natural veneer and piano finish according to customer requirements.

 

Converters

Low and mid frequency range is covered by a pair of 6.9 "(175 mm) transducers. The high capacity and extremely long linear excursion (+ /-12mm) provides clean and undistorted reproduction even at high levels. They are placed in closed baffle, which acts as a 2nd order filter with a much better pulse and phase response than 4th to 6th order filters used in conventional bass-reflex type. The high frequency driver has a unique ring diaphragm ("Ring Radiator") with many advantages compared to standard dome design. Phase plug and nearly flat membrane, with an additional acoustic chamber guarantee an extremely flat amplitude and phase response and wide and uniform directivity.

The diaphragm is attached in the centre and the periphery with the coil attached in the middle of these points. This prevents the deformation of the membrane at high levels and frequencies (called Breakdown Mode). Impregnated soft material diaphragm provides a detailed and enjoyable listening without any misleading additional sound caused by its own resonanc.

 
Electronics

Analog input is electronically balanced with a very high CMRR meeting the highest professional demands. Digital input is AES/EBU and SPDIF RCA/optical. Our own DA converter (24 bit/192 kHz), same as in the Ellipse, is featuring the latest DA converter chip from the world-famous manufacture. Active crossover an EQ circuits ensure all necessary corrections to achieve flat amplitude and phase characteristics and optimise the impulse response. Setting the level of individual frequency bands and variable low-frequency equalization can be used for compensated of the impact of room acoustics, as well as customise the listener tastes. The overall gain, the level of high and low frequency and LF equalization is controlled by a microprocessor. Settings can be stored in memory and recall at any time. Comprehensive protection circuits with optical limiters prevent the possibility of overloading drivers and unwanted distortion. Two D class switching power amplifiers are using a number of revolutionary principles (Controlled Oscillation Modulation, Multivariable Enhanced Cascade Control). In addition to providing high-efficiency parameters, placing them at the forefront of the highest category. Switching power supply provides stable power for amplifier and electronics with no possibility of 50Hz hum and transformer mechanical noise.

Technical Parameters

System: 2-way active system
Frequency response:
34 Hz  - 21 kHz  (+/- 3dB)
Max  SPL 1 m,1pair, IEC short-term:
118 dB  peak
Volume Control:
-99dBu to +15 dBu, 0,5dB step
Input impedance:
20 kOhm balanced

High/Low level setting: +/- 6 db ,1 dB step
Low EQ:
-4dB, -2dB, 0dB, +2 dB
Speaker Protection:
Power-on mute,  power and excursion limiter, limite a clip limiter

Dimensions (H x W x H): 1320 x 300 x 300 mm
Weight:
30 kg
Power amplifiers:
D class, 2 x 250W

THD +N: 4Ohm, 1W, 1 kHz 0,006 % typ.
IMD:
Po=10W, 0.005% typ
TIM:
Po=10W, 3,15/15kHz square 0,003% typ.