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Last but not least is the remapping technology based on calculating the acoustic field produced by all speakers. This calculation is possible thanks to a Fourier-Bessel decomposition of the acoustic field into a certain number of coefficients which correspond to spherical harmonics. Just as Fourier decomposition is commonly used to analyze a signal in the frequency domain, the Fourier-Bessel decomposition can be used to analyze an acoustic field in the space domain by decomposing into a sum of elementary radiation patterns which math refers to as spherical harmonics. The function that provides the resultant acoustic field from the input signal is called a radiation matrix. In a pseudo math notation this becomes input signal * radiation matrix = acoustic field.


The Optimizer first computes the radiation matrix which corresponds to the measured loudspeaker positions. This is possible because the exact positions of the loudspeakers were already mapped in 3D. The radiation matrix now allows calculations about the acoustic field produced by the measured loudspeaker placement. But the Optimizer can also calculate the radiation matrix for a reference or ideal placement. Now the radiation matrix for the reference system can define the ideal acoustic field produced if the loudspeakers are positioned according to the ideal placement. The last stage consists of finding out what additional processing should be applied to the input signal to obtain the ideal acoustic field from the measured speaker system. This is done by inverting the real radiation matrix: remapping matrix = radiation matrix of the ideal system * (radiation matrix of the real system) -1.

This remapping matrix is computed once after the loudspeaker positions have been measured and applied in real time to the input signal to obtain the reference acoustic field. And that’s all I shall say about software and math. It’s impossible to completely avoid this brainy topic when one has such an advanced device under consideration. Let’s focus now on pure audio features. Trinnov’s high-end stereo flagship combines an 11-source preamplifier with built-in room/speaker optimizer, Trinnov’s innovative hybrid phono preamp, a network renderer, a 24/192 A/D/A converter and a 2-way intelligent active crossover engine. The Amethyst also features built-in WiFi connectivity. As a very exhaustive preamplifier or perfect Victorinox Swiss Knife adapted to audio, the Amethyst offers two balanced analog inputs, one single-ended analog input, a second single-ended analog input switchable to MM phono, two AES/EBU digital inputs, 2 coaxial S/PDIF, two Toslink and a high-resolution UPnP network on Ethernet and WiFi.

What’s completely new for a digital specialist is the hybrid technology of the innovative RIAA filter which combines an analog circuit for the low-end and a dedicated digital algorithm for the high frequencies. Both filters cross around 1’000Hz. The network capabilities add full compatibility of sources. The Amethyst network streamer is based on the universal plug and play or UPnP network protocol. In UPnP/DLNA terminology, the Amethyst is a UPnP digital media renderer and used as slave to play media content through the network. The Amethyst must be used with DLNA/UPnP compatible server/controller devices. The media server shares its media library with UPnP clients over the network. The media controller is the master device used to auto detect servers and play files on slave devices as well as to control them.


The Amethyst supports WAV, AIFF, OGG and FLAC up to 24/192. The sole limitation is DSD playback which is incompatible with digital post treatments and the concept of speaker & room correction itself. But I could still use my DSD music library through the on-the-fly DSD-to-PCM conversion feature of my Lumin network player. The Amethyst becomes part of your home network like any laptop, smartphone or tablet connected to the Internet router via wireless connection but the Amethyst can also be hard-wired to the router using a basic DHCP protocol.