The M-1sis were set up in Stereophile's 15.5' by 20' by 9' listening room. CD-based material was used for most of the auditioning, either original CDs or compilation CD-Rs dubbed from my own CD collection. The remainder of the system consisted of the Mark Levinson No.35 D/A converter, the Pioneer PD-65 CD player used as a transport from its coaxial digital output (and also, briefly, the C.E.C. TL 1 transport), the Rowland Consummate preamplifier, and the Bryston 7B monoblock amplifiers in their series mode. The digital interconnect was a Kimber KCAG coaxial,…
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Sidebar 2: Of Monopoles, Bipoles, & Dipoles
For the benefit of those who may not have seen GL's review of the similarly conceived M-3si (or our earlier reviews of the original M-1 and M-3), a bipolar design differs from both conventional front-radiating loudspeakers and dipole designs.
The former, of course, describes 90% of the loudspeakers on the market. One or more drivers radiate from the front of an enclosure, which may be configured as a rectangular box (usually), or—if the designer is adventurous and the budget open-ended—as any one of a myriad of other shapes. The…
Sidebar 3: Measurements
The Mirage M-1si's impedance curve in fig.1 indicates a load which should be easy to drive. The magnitude of the impedance never drops below 4 ohms or rises above 8.3 ohms, except at the lowest and highest frequencies. The peak at 24.6kHz could be caused by a "trap filter" to tame the high-frequency resonance of the tweeter. The average tuning of the ports is 29Hz—indicated by the "saddle" between the double peaks in the bass magnitude plot. The smaller peaks at 300Hz and 2.5kHz are a reflection of the effective electrical crossover points, the former somewhat…
Tom Norton returned to the Mirage M-1si in October 1993 (Vol.16 No.10):
Though Stereophile's samples of the Mirage M-1si have long since gone back to the manufacturer, I recently had the opportunity to hear them in another application in a visit to the facilities of Widescreen Review. Editor Gary Reber had two pairs of them in his main audio/video setup, one pair for the fronts, another for the surrounds. No center-channel loudspeaker was in use when I heard the system, nor were there any subwoofers. The latter was a temporary omission—a new pair of subs from Mirage was expected any day…
Sidebar 4: Specifications
Description: Three-way, reflex-loaded, bipolar loudspeaker system. Drive-units: two 1" (25.5mm) titanium hybrid-dome tweeters, two 5" (127mm) injection-molded polypropylene-cone midranges, two 8" (203mm) Polyflex treated, carbon-filled polypropylene-cone woofers with 1.5" (38mm) voice-coils. Crossover frequencies: 400Hz, 2kHz. Frequency response: 25Hz–33kHz ±2dB (on-axis), 25Hz–20kHz ±2dB (30° off-axis). Usable bass response: –10dB at 17Hz. Sensitivity: 82dB at 2.83V (1m), anechoic, 86dB in-room. Nominal impedance: 6 ohms, 4 ohms minimum. Amplifier requirements…
Among the most hallowed of my ten or so (the number varies) personal commandments of high-end audio is the following (to be uttered in sepulchral tones with deep humility):
You have to spend a lot of money only to discover that you didn't have to spend a lot of money.
Needless to say, given the inherent snobbery of old-time tweaks and the fundamentalist fervor of recent converts, thousands of acres of old-growth forest have been pulped in the expression of all the conflicting opinions as to what constitutes the outer limits of true high-end performance, and at what price…
"For instance, some transformers are simply dipped into varnish; but the ones we're using are left in the varnish for 24 hours, which allows the varnish to filter into all parts of the transformer—so you'll find our transformers are very quiet. The transformer is also decoupled from the chassis by employing certain materials underneath to filter out mechanical vibrations. Otherwise, that noise is making the case vibrate. Likewise, because the [printed circuit board] is attached to the transistors, if the board isn't also decoupled from the casing, all of that is singing together."
"And…
Sidebar 1: Specifications
Description: Solid-state integrated amplifier. Power output (both channels driven): 50Wpc into 8 ohms (17dBW), 90Wpc into 4 ohms (16.5dBW). Frequency response: 10Hz–40kHz, ±3dB. Total Harmonic Distortion: 20Hz–20kHz, ±0.02%. S/N ratio: !w95dB (A-weighted). Power consumption: 260W (full power).
Dimensions: 4.25" (105mm) H by 17.5" (442mm) W by 12.75" (320mm) D. Weight: 19 lbs. (8kg).
Serial number of unit reviewed: I 000108.
Price: $995; remote control adds $50. Approximate number of dealers: 35.
Manufacturer: Audio Refinement. Distributor: Audio…
Sidebar 2: System & Setup
I went into a good bit of detail about my system in the November 1998 Stereophile (Vol.21 No.11, p.105), when I reviewed the Joseph Audio RM22si loudspeaker. While there's no need to reprise everything here, my system has since undergone some fundamental changes in core components and tweaks that are worth mentioning.
I'm still using a pair of 20' JPS Labs Superconductor speaker cables to biwire the Joseph RM22si's. They have a really nice tonal balance, a smooth top end, and excellent bass focus. The replacement of my Dual CN5000/Ortofon XM5 combo…
Sidebar 3: Measurements
All measurements of the Audio Refinement Integrated, except as noted, were made at a level-control setting that resulted in a 1W output into an 8 ohm load with an input of 100mV. The physical position of the level control for this condition was approximately 3:00, the voltage gain into 8 ohms 29.2dB at this setting.
The amplifier was very warm, but not hot, following its 1-hour, 1/3-power preconditioning test (conducted at 8 ohms). Its line input impedance measured 54.4k ohms. This decreased to 18k ohms at the level control's maximum position, and…