The TacT RCS (Room Correction System) 2.0 is an up-to-date manifestation of a…
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I anticipated the installation of the TacT Audio RCS 2.0 room-correction processor with mixed emotions—I already liked my system and room, and such a device threatened to make all my studied efforts trivial. What if one might use any decent amps and speakers, cables that were merely conductive, and no room treatment at all? And what if, on top of that, you could just put them wherever your significant other thought they looked right? What if all the magic you needed was contained in this box? Scary.
How to listen?
Assessing the overall performance of the TacT RCS required me to distinguish the RCS's DSP/room-correction capabilities from its other capabilities. I began by evaluating the RCS's own DAC by running digital lines from the TacT to the Perpetual Technologies P-3A and Mark Levinson No.360 DACs, and coaxial analog lines from the TacT, PT, and ML to my Sonic Frontiers Line-3 preamp. All three inputs were gain-adjusted at the preamp to give equal output. A/B/C comparisons revealed that each DAC sounded so subtly different as to leave me unable to express a strong preference.…
Assessing the overall performance of the TacT RCS required me to distinguish the RCS's DSP/room-correction capabilities from its other capabilities. I began by evaluating the RCS's own DAC by running digital lines from the TacT to the Perpetual Technologies P-3A and Mark Levinson No.360 DACs, and coaxial analog lines from the TacT, PT, and ML to my Sonic Frontiers Line-3 preamp. All three inputs were gain-adjusted at the preamp to give equal output. A/B/C comparisons revealed that each DAC sounded so subtly different as to leave me unable to express a strong preference.…
I had intermittent problems switching between correction filter modes on the RCS. Selecting a particular correction from the remote or the keypad on the front panel sometimes muted the output and sometimes made a clearly spurious correction. There were also times, when switching among inputs, when the RCS failed to access the new input. In both situations, switching to Bypass and/or to another input and back successfully recovered the desired function.
What did it sound like?
Objectively, as measured by the ETF and the Sencore analyzers, the RCS accomplished three things. First, it…
Hoary old platitudes
The walls melted away. I was transported to the performance. The speakers disappeared. A veil was lifted. Yadda yadda yadda.
The walls melted away. I was transported to the performance. The speakers disappeared. A veil was lifted. Yadda yadda yadda.
Well, excuse me! These clichés accurately describe the RCS's removal of my listening room's superimposed character. It permitted me to hear the low-level ambience cues of the original performance sites. This information was already on the recordings, but now I was simply hearing more of it, and better. The rain during Ivor Humphreys' flute solo on an old Hi-Fi News & Record Review test CD, and the various activities, acoustic and…
Sidebar 1: Specifications
Description: Two-channel DSP-based room-correction system and digital preamplifier. Includes complete FFT measurement system, calibrated microphone, digital volume control with 0.1dB resolution, IR remote control, 2 RS-232 ports, 1 microphone input (XLR). Digital inputs: 3 S/PDIF, 1 AES/EBU, 1 TosLink. Digital outputs: S/PDIF, AES/EBU, TosLink. Optional: ADC and 4 analog inputs (3 RCA, 1 XLR). Optional: DAC and 2 analog outputs (RCA and XLR). Resolution: 16-24-bit. Sampling frequencies: 44kHz, 48kHz, 96kHz. No distortion or noise in digital domain. Power…
Sidebar 2: Speakers, Rooms, & Flat Response
At first glance, it seems reasonable to regard the tonal balance of a real speaker in a real room as the sum of the performance characteristics of speaker and room. If there's something amiss in the sound, just find the offending frequencies, by ear or meter, and adjust the incoming signals with an equalizer.
Unfortunately, rarely will the result be the desired flat response. There will be a change, but, depending on how and from where you listen, there may or may not be an improvement. The reason is that the interaction of speakers…
Sidebar 3: Associated Equipment
Analog source: Heybrook TT2 turntable, SME III tonearm, Ortofon SME30H cartridge.
Digital sources: Meridian 800 DVD/CD transport, Mark Levinson No.360 DAC, Perpetual Technologies P-3A DAC, Philips SACD 1000 SACD player.
Preamplification: Sonic Frontiers Line-3 preamplifier, Audiolab 8000PPA phono stage.
Power amplifiers: Bel Canto EVo 200.2 monoblocks, McCormack DNA-1 with SMc Rev.A mod, Sonic Frontiers Power-3.
Loudspeakers: Revel Ultima Studio.
Cables: Interconnect: DAC-preamp: Cardas Golden Cross, Straight Wire Maestro II. Preamp-power:…
Sidebar 4: Measurements
As supplied for review, the TacT RCS 2.0 comprises three separate components: a D/A processor, an A/D converter, and a digital equalizer. I therefore examined the TacT's measured performance in each of those regions.
Looking first at the D/A converter section with the digital EQ set to Bypass, the RCS 2.0's maximum analog output level was 1.671V from the single-ended outputs, 3.356V from the balanced, with the volume control set to "93.9," the unity-gain setting. (The volume control goes up to an indicated "99.9"; ie, a maximum gain of 6dB, in accurate 0.…
Confirming the excellent resolution and dynamic range seen in fig.3, the RCS 2.0's DAC linearity error was less than 1dB down to below -110dBFS (fig.5), which is superb. As a result, the TacT's reproduction of an undithered 1kHz sinewave at -90.31dBFS was effectively perfect (fig.6), while increasing the bit depth to 24 bits gave a reasonable facsimile of a sinewave (fig.7), even at this very low level.
Fig.5 TacT RCS 2.0 D/A module, departure from linearity, 16-bit data (2dB/vertical div., right channel dashed).
Fig.6 TacT RCS 2.0 D/A module, waveform of…
However, other than this behavior and the presence of power-supply-related artifacts, the TacT's D/A section offers very high performance. This is particularly notable in that it adds only $599 to the unit's price.
The $699 A/D module operates at 44.1kHz, 48kHz, and 96kHz sample rates, these selectable by navigating the front-panel keypad. Its input impedance was a moderate 18.6k ohms via the balanced jacks, but a low 4.6k ohms via the single-ended RCA jacks. Some capacitor-coupled, tubed phono stages might sound too lean with this low a load. The A/D frequency response was flat (not…