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Boston Acoustics M350 loudspeaker Measurements

Sidebar 3: Measurements

I performed the farfield measurements on the Boston Acoustics M350 using DRA Labs' MLSSA system and a calibrated DPA 4006 microphone. For the nearfield and spatially averaged room responses, I used an Earthworks QTC-40 microphone.

My estimate of the M350's voltage sensitivity on its tweeter axis matched the specified 89dB(B)/2.83V/m, which is a little higher than the norm. Specified as a 4 ohm load, the M350's impedance magnitude (fig.1, solid trace) remained between 4 and 6 ohms for much of the audioband, dropping to a minimum value of 2.85 ohms at 138Hz…

Listening #128

Writing is easy. See? I just did it. Three whole sentences, written between breakfast and lunch. (I had to pause and think about one of them.) Payday, here I come.

What isn't easy is performing some of the tasks that make writing worth reading. My least favorite of those is receiving equipment samples that are too large or too heavy for UPS and FedEx: Few things strike greater fear in my heart than having a tractor-trailer driver call me from his cell phone, saying he's blocking traffic at the bottom of my driveway and wants to know how to reach my house—and, by the way, his liftgate is…

Listening #128 Page 2

In our efforts to describe the musical worth of a hi-fi product, reviewers often try a little too hard to select recordings that might impress the reader with their rarity, their obscurity, or their sheer coolosity. I've been guilty of that myself, but over time I've made an effort to resist temptation and either surrender to the musical—rather than the sonic—whim of the moment, or else to reach, blindly, for whatever my fingers find on the shelf: If it's in my collection, it must be worth hearing at least once, right? (footnote 3)

So it was during the Ikeda's time in my home, during…

Listening #128 Contacts

Sidebar 1: Contacts

EMT Studiotechnik GmbH, Industriestrasse 25, 77972 Mahlberg, Germany. Tel: (49) (0)7825-879-47-0. Fax: (49) (0)7825-879-47-15. Web: www.emt-studiotechnik.de. US distributor: Tone Imports. Web: www.toneimports.com

Ikeda Sound Labs. US distributor: Beauty of Sound, 13 Country Lane, East Greenbush, NY 12061. Tel: (518) 852-9183 Web: www.beautyofsound.com.

Listening #128 List of the Month

Sidebar 2: List of the Month

The Most Valuable LPs in My Collection. Don't laugh, but while researching LP prices for last month's column, I grew addicted enough to such record-pricing sites as Popsike.com and Collectorsfrenzy.com that I've since devoted occasional free minutes to researching titles in my own collection. As it turns out, some of the ones I thought might be worth something really aren't, and vice versa. Here is a random and by no means complete sampling of the LPs in my collection with the greatest monetary value. All but one are records I've bought strictly for pleasure…

Schiit Audio Bifrost D/A processor

Late last year came an epic audiophile moment: I slapped a final length of tape on the box of the awesome-sounding MSB Diamond DAC (Stereophile, October 2012), in final preparation for its trek to John Atkinson's testing lab, in Brooklyn. Next up was the Bifrost DAC from Schiit Audio. I popped it into my system, where, moments before, the MSB had held court.

From $43,325 to $449. Yowseh!!—the MSB costs almost 100 times as much as the Schiit! Was this even fair?

The Bifrost wasn't warmed up, and it certainly hadn't settled in—but who could resist a little listening? I switched on…

Schiit Audio Bifrost D/A processor Page 2

A Tale of Two DACs
Back to those Turtles tunes. I was deflated. Musical life and drama were diminished, and a hazy cloud (not a flaming rainbow) had settled on the system. I was worried Odin might show up.

Of course, if the Bifrost had actually stood up to the $43,325 MSB, I would probably be deflated at how easily the MSB was dethroned. But no, the cosmic order of DACs was maintained, and in this case there's something to be gained by throwing lots of money at a design. In the context of DACs, the contrast was stark (ie, not as stark as in most contexts), and started me off on the…

Schiit Audio Bifrost D/A processor Specifications

Sidebar 1: Specifications

Description: Solid-state D/A processor. Inputs: coaxial S/PDIF, optical S/PDIF, USB (optional, included with review samples). Input capability: up to 24-bit/192kHz, all inputs. Input receiver, S/PDIF: Crystal Semiconductor CS8416. Input receiver, USB: C-Media CM6631A. D/A conversion IC: AKM4399. Output: RCA (single-ended). Output impedance: 75 ohms. Frequency response: 20Hz–20kHz, ±0.1dB; 2Hz–100kHz, –1dB. Maximum output: 2.0V RMS. Upgradability: separate, modular USB input card and DAC/analog card (both snap-in, replaceable). Power consumption: 12W.
Without…

Schiit Audio Bifrost D/A processor Associated Equipment

Sidebar 2: Associated Equipment

Digital Sources: Apple MacBook Pro computer (2.66GHz Intel Core 2 Duo, 4GB RAM, 320GB HDD) running OS 10.6.7, iTunes 10.6, Sonic Studio Amarra Computer Music Player 2.5, Songbird 1.9.3, XLD; Western Digital NAS Device 2TB; Oppo BDP-103 universal Blu-ray player; Meridian (formerly Sooloos) Digital Media System (Control 15, TwinStore x3); Apple iPad 2, 3 (or "New iPad" or latest or HD or Retina or whatever); Apple iPod Touch 1G, Apple iPhone 4S.
D/A Converters: Benchmark DAC1 USB, M2Tech Young with Palmer power supply, AudioQuest DragonFly, Wadia 121.…

Schiit Audio Bifrost D/A processor Measurements

Sidebar 3: Measurements

I examined the Schiit Bifrost's electrical performance with Stereophile's loan sample of the top-of-the-line Audio Precision SYS2722 system (see www.ap.com and the January 2008 "As We See It"). To test the USB input, I played files with Bias Peak Pro running on my MacBook Pro, using the AudioMIDI utility to make sure that the data output from the USB port had the correct sample rate and bit depth. I performed a complete set of measurements on both samples and have noted in the text where these differed.

The coaxial input of both samples locked to…