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The user can define any number of measurements and weighting wherein the first is always the reference measurement for the central listening position. Three to eight measurements are recommended on and around the listening position. Graphics optimizer shows the visual measurements, corrections, frequency response, phase response, group delay and pulse waveform of each point measured. Further criteria such as level and run-time differences between speakers and subwoofers can also be corrected automatically.


Click to begin calibration and the Trinnov will pulse each channel in sequence with a blast of test noise. It will require sufficient output to measure correctly and warn you if the volume is too low. To not blow out your speakers you will progressively increase the volume. In my system and with my loudspeakers the level of calibration requirement was met at around -12/-10dB. The Trinnov then quickly displayed a list of each connected speaker, its distance in centimeters from the listening position and its vertical and horizontal angles to that position. At this stage you should have an accurate assessment and mapping of the symmetry of your speaker placement. If you're not happy, you can now move your speakers or re-aim the mike pod more carefully at the center speaker (whether real or virtual) and repeat the measurements. When all is to your satisfaction, click again to begin the computation for the correction curves.


You also have to define how/what you want to measure. The basic and recommended option is to plug the Trinnov into your amplification device to obtain the most precise view of your room’s intrinsic acoustic. But it is also possible to insert the ST2-HiFi ahead of your preamp or D/A converter. Then you will measure the overall frequency response of your entire system. I personally stuck to the basic approach and connected the Trinnov directly to my Orpheus monaural amplifiers.


Early setup.
Now things become more complex. I cannot say it was a particularly difficult exercise but it was complex due to the large number of available options. I think anyone will have to spend many hours and days to explore the various options this device makes available; and to then fine-tune the automated response for even more satisfying results. In some ways everyone listener must decide where to be between automatic and fully manual mode. If you are looking for more than averaged results, you will by necessity have to address a few things manually. My goal now is not to copy the user manual but to provide you with some illustrations of the ST2-HiFi’s main functionalities. I will not even touch the very complex matter of active crossover settings even though that represents one of the very interesting advanced functions proposed by Trinnov.


The profiles configuration page defines the default settings for each input. The Trinnov is able to handle up to 16 channels simultaneously. Even if some default presets have already been saved to the ST2-HiFi, this stage remains a necessary transition to define the main profiles and presets to be automatically reloaded. Each preset can be renamed to get a more precise description. Apart from the selection of specific analog or digital input, each profile can be assigned a specific clock mode and sample rate to then control the synchronization of the Trinnov when a profile is selected. This enables direct association of hardware input/output routing with a specific correction filter, source setting and speaker layout configuration. It is also possible to select a specific EQ to be recalled directly when hitting the profile button. The master level may be adjusted separately for each profile.


The power on default option starts the optimizer with the profile of your choice. The source settings window is used to define incoming sources and their respective formats (i.e. number of channels and technical specification formats for broadcast or film). This input format information is necessary to reference the positions of the loudspeakers for remapping. I worked most of the time with the basic stereo ITU setting but it is also possible to define the number of LFE signals feeding the optimizer. If a LFE channel is assigned to the sources settings, the LFE channel is always placed last after all the other channels. The advanced settings for each source allow mixed use of the Trinnov for home theater and stereo to make for a very flexible versatile tool.


After the sources have been fixed, one addresses the loudspeakers settings. There you can set the number of speakers and subwoofers. If more than one sub is used, the ST2 HiFi will create copies of the first input LFE signal. Changing the loudspeaker settings might require starting a new recalibration process. Bass management allows subwoofers to receive low frequencies from the main channels below the chosen crossover frequency. The Trinnov will align the output levels of all speakers including subwoofer/s. An independent +10dB option allows for the correction of playback sources that generally set the LFE to –10dB relative to the other channels to ensure adequate headroom for the LFE track. For a traditional 2.1 setup, the common setting is bass management enabled in monaural mode (it filters the low frequencies from the main channels at the designated crossover point whilst the LFE channel itself remains unfiltered). The subwoofer will have to be connected from the sub 1 output on RCA or XLR to its direct input. Now the Trinnov enables very precise fine-tuning of the 2.1 or 2.2 configuration, always a delicate problem for audiophiles and not always easily adjusted from the subwoofer’s rear panel directly.


A lot of windows are dedicated to adjusting the room correction manually. The processor input and output windows for instance include 31-band 1/3rd octave graphic equalizers to manually EQ each input or output channel. These filter modifications are applied in real time so you can hear them but they are not visible in the on-screen frequency response curves. This makes for a gradual approach to fine-tuning the in-room frequency response of your speakers - not so bad. The ST2-HiFi gives you the choice between preset EQ and user EQ for the output channels. The preset EQ reloads and saves for the whole preset while the user EQ can be saved and reloaded independently from the current preset. This last option gives the flexibility of having one reference equalization curve that can be used directly atop the optimizer presets. If you own additional measurement tools it is also possible to let the Trinnov generate pink noise to help you dial in your personal settings.


Optimizer’s main functionalities.
The runtime screen allows modular activation of the Trinnov’s main functionalities. It is possible to bypass all processing related to the various acoustic correction settings and remap options together or separately. Then the acoustic correction (automatic equalization and FIR), level alignment and delay alignment can be bypassed independently. The bypass function will not however disable the manual equalization settings that were previously defined in the processor and the bass management windows.


The main settings provide the option between global acoustic correction of amplitude and phase or amplitude only. The ST2 HiFi obviously works only over a specific range of boost and attenuation. The maximum boost setting defines the automatic dB limit within which the algorithms will be applied. This parameter cannot be disregarded so as to keep distortion at low levels. It’s rather more complicated to apply boost than attenuation. Boost here has a default value of +6dB. It seems reasonable keeping this within a 2-6dB range. In the same vein the maximum attenuation setting defines the amount of attenuation in dB which the Trinnov will apply in automated mode. The quantity of early reflections option characterizes the width of the time-frequency window, i.e. the number of early reflections the optimizer will try to compensate for. The resolution of energy response preset impacts the correction of the late reverberations. The default setting is half an octave. It will deliver a smoother energy response for more natural sound reproduction than when taking into account sharper peaks in the room's energy response (1/3rd or 1/6th octave for example).


The 3D remapping function enables full spatial 3D optimization. This allows for compensating incorrect loudspeaker positioning in azimuth and elevation where Trinnov remapping adjusts for the virtual positions of each channel. It seems more like a home-theater option to adjust the center channel which commonly sits above or below the video display. 2D remapping can be used for both hifi and home-theater applications to adjust an asymmetric position of left and right channels or to handle various seating listening positions.


I would advise all Trinnov newbies to experiment extensively with the above parameters. I personally considered it a very meaningful lesson to learn what kind of effect on the sound each small variation of any one particular setting had. One of the most advanced and powerful tools of the Trinnov ST2-HiFi arsenal is the target curve module. The optimizer implements target curves for achieving a desired frequency response from the playback system whereby the algorithms automatically compute the necessary counter filters to obtain it. A target curve for each speaker can be defined for amplitude only, amplitude plus phase or amplitude plus group delay. It is even possible to link several channels together to share the same target curve for multiple speakers. By default the optimizer uses both IIR and FIR filters to achieve the target curve. One of these filters can nevertheless be disabled in the advanced settings window. Using FIR only means that the optimizer will just address the mid and high frequencies (i.e. bass will not be corrected). IIR-only mode works exclusively on the bass by disabling FIR and FIR EQ filters.


A completely flat frequency response curve is very often not the most desirable goal as it might deliver quite unsatisfying results. The ideal curve will depend on the listening room’s features and the personal preferences of each listener. Storing several target curves according to different musical genres is an interesting option. But it is important to first achieve a ‘reference’ or base-line curve (with edits for amplitude, group delay and phase). In my opinion it is vital also to keep in mind that attenuation of the original uncorrected response is more efficient than boosting it. The perfect target curve for your ears will in some ways be a kind of very sensitive compromise.


Sonic experience.
Every audiophile generally cares a great deal about sound quality yet are they all prepared to build their own sound? That's really the main question Trinnov’s invasion into the home market asks. After all, Trinnov deals with compensation, nothing else. If you are dogmatically attached to sonic purity and straight-wire logic, it may be difficult to embrace all the enhancement subtleties the ST2-HiFi proposes. Trinnov calls for adjustments to the sound whose subjective response could be overwhelmingly positive to fly in the face of puritan notions.

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