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Cable manufacturers Nordost and Vertex AQ had good reason to present their joint seminar, "New Approach to Audio Measurement: Why Cables Really Matter," no less than five times during the show. As Art Dudley will report at length in his December "Listening" column, their groundbreaking new approach to measurement, developed by Nordost and Vertex AQ in collaboration with military electronic-engineering consultant Gareth Humphrey Jones, has produced an entirely new method for measuring the audible effects of components on sound. We're talking not only cables, support platforms, and the…
I was glad that Darren and Bonnie Censullo's Avatar Acoustics demmed four new products at RMAF, because they created a synergistic match that produced beautiful sound.
The four products were the AMR (Abbingdon Music Research) CD-777 CD player ($3995), AMR AM-777 ($3,995), Dr. Feickert Analogue Woodpecker Turntable ($4995), Dr. Feickert Analogue DFA 10.5 tonearm ($1250, or $1000 with the table), and Rethm Maarga loudspeaker ($6995/pair). I initially encountered some insipid analog drivel when I entered the room, but I thumbed through a collection of LPs and came up with a choral…
Bass quality seemed to improve when Bockrath and I placed the sub to my left, mostly clear of the desk, a change that prompted the creation of another room-correction curve. However, my thoughts on subwoofer placement changed once serious listening began. I moved the sub back under the desk, which necessitated yet another Dirac room correction curve.
By the time Bockrath left, all components of the Mini Dragon system seemed to work properly. A short time later, though—when I was playing a minimally dynamic file of soprano Maria Callas, sourced from a live mono radio broadcast—the system…
Sidebar 1: Specifications
Description: Nearfield playback system with dipole planar-magnetic satellites, subwoofer, amplifier with DSP loudspeaker controller, and headphone amp/streamer with DSP room correction (Dirac Live). Also supplied: calibration microphone and cabling. Frequency response: 30Hz–50kHz. THD: <1% at 100dB.
Price (system): $10,000. Approximate number of dealers: not disclosed; also sold direct. Warranty: 3 years.
Manufacturer: Dragonfire Acoustics, Orange County, CA. Tel: (657) 667-6187. Web: www.dragonfireacoustics.com.
Mini Dragon Satellite…
Sidebar 2: Associated Equipment
Digital sources: Apple 27" iMac, 2017 w/3.8GHz Intel Core i5, running Roon 1.6 (build 416); Linksys router with Small Green Computer linear power supply; G-Technology external HDs and Linksys SSD USB sticks; Mytek Manhattan II D/A processor.
Loudspeakers: Dynaudio Focus 110A powered loudspeakers.
Cables: Digital: Nordost Valhalla 2 (USB), Wireworld Platinum Starlight CAT8, AudioQuest Diamond (Ethernet). Interconnect: Nordost Odin 2. AC: Nordost Valhalla & Odin 2.
Accessories: Nordost QB8 and QV2 AC power accessories; Nordost Sort Kones and…
Two 30W class-D amplifiers drive the tweeter module and the woofers. DALI says these amplifiers are rated for 10 times the peak-to-average power required in normal use and can deliver 250W for up to 5 seconds. The crossover is implemented in the digital domain, and volume control takes place just before the speaker's Burr-Brown PCM1796 balanced-output DACs to maintain 24-bit resolution.
Callisto 6 Cs are assembled in Denmark with a Danish cabinet and components manufactured in the DALI factory in Ningbo, China.
Setup
Once the Sound Hub and Callistos are powered up,…
Sidebar 3: Measurements
I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Dragonfire Mini Dragon Satellite's frequency response in the farfield, and an Earthworks QTC-40 mike for the nearfield responses of that and the SB-8P powered subwoofer. I measured the performance of the Dragonfire MD-4 power amplifier with my Audio Precision SYS2722 system (see the January 2008 "As We See It"). Because the MD-4 uses a class-D output stage, around 320mV of ultrasonic switching noise was present on its outputs. As this noise might overload the SYS2722's input…
Sidebar 1: Specifications
Dali Callisto 6 C
Description: Three-way, wireless, floorstanding, reflex-loaded, powered loudspeaker with touch-sensitive volume control. Drive-units: 0.67" by 1.77" (17 by 45mm) ribbon supertweeter, 1.15" (29mm) soft-dome tweeter, two 6.5" (165mm) woofers with pulp/ wood-fiber cones. Crossover frequency: 2.6kHz. Bass reflex tuning frequency: 40Hz. Frequency response: 37Hz– 30kHz, ±3dB. Internal DSP resolution: 24 bits/96kHz. Inputs: 24/96-capable wireless; analog (RCA). Analog input impedance: 5k ohms. Analog input sensitivity: 1.85V for maximum output.…
Sidebar 2: Associated Equipment
Digital Sources: Roon Nucleus+ file server; Ayre Acoustics C-5xeMP universal player; PS Audio PerfectWave DirectStream D/A converter; Digital Domain VSP digital audio control centerm Ayre QA-9 and Benchmark ADC-1 A/D converters.
Cables: Digital: AudioQuest Vodka (Ethernet), DH Labs (1m, AES/EBU), Esperanto Audio (1m, S/PDIF). Interconnect: AudioQuest Wild Blue (balanced), AudioQuest Fire (single-ended). AC: AudioQuest Dragon Source & High Current, manufacturers' own.
Accessories: Target TT-5 equipment racks; Ayre Acoustics Myrtle Blocks; ASC…
Sidebar 3: Measurements
I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the Callisto 6 C's frequency response in the farfield, and an Earthworks QTC-40 mike for the nearfield and in-room responses. I fed the test signals to one of the speaker's analog inputs. The volume control is deactivated with the analog input, and the DALI's specified sensitivity with analog signals is 1.85V for maximum output. Pink noise with a level of 100mV RMS gave a sound pressure level of 91dB(B) at 1m on the supertweeter axis. The volume control is active with digital input…