Exclusive First Review!Pass Labs SR-2 Three-Way LoudspeakerDelivers Audiophile Class, Sound Quality

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Price: $18,000

Likes: Peaceful, easy signature

Dislikes: no piano black gloss

More info: Pass SR-2

by John Gatski

  Best known for its superb-sounding amplifiers and preamplifiers, Pass Labs has rarely produced loudspeakers. The grande-sized Rushmore. manufactured from 2003-2008, was a fantastic speaker, though up there in price — and it weighed a ton (not really, but seemed like it). I listened to it at CES a few time and liked its rock solid, deep bass and ability to beam its energy into a big room.

  Pass Labs’ current line of speakers includes two-models in the SR-Series, They are said to continue the rich, music reproduction of the Rushmore, but in smaller packages and at more typical audiophile prices. The models are the top-of-the-line. dual-stacked cabinet SR-1 4-way and the uni-cabinet SR-2 3-way.

  I put in my request for a review pair of the entry model SR-2 three-way, a tower speaker that looks like it costs a lot more than its $18,000 per pair list price. This speaker offers a no-hype, high-caliber transmission of sonics that is old school smooth and gimmick free. It relays high-resolution music with a keen accuracy and much welcome, tight, deep bass from its port-assisted cabinet. As I discovered during the review process, it matched well with Pass’ amps, as well as various other amp designs.

Features

  The made-in-USA SR-2 is a very handsome tower speaker, finished in a cherry finish back and sides and black angled front baffle. The three-way, bass-reflex design is equipped with three, custom-made SEAS Nextel drivers, consisting of a 10-inch bass driver, 6-inch midrange and a 1-inch HEXADYM tweeter. The premium Nextel Series SEAS drivers are not the latest in metal dome technology, but are hybrid paper/textile composites that make for a transparent, clean, smooth, tonal characteristic that is not hyped anywhere in the spectrum.

  The 12 dB-per-octave second order crossover frequencies are centered at 126 Hz and 3.2 kHz. The crossover circuit contains premium parts including polypropylene capacitors from Kimber and Solen, Mills resistors, and high-current Erse inductors, all mounted on thick, heavily plated circuit boards. The wire is the same used in the output stages in Pass amplifiers

With the original Rushmore as its inspiration, and Pass’ dedication to high-end quality hi-fi, the SR-2 is as fine loudspeakers as you could buy out to about $40,000. Its accurate tonal spectra, classy build and good looks net it a Stellar Sound Award.

  The other key to the speaker’s performance is its cabinet, a heavily-braced, solidly built MDF enclosure — with cherry veneer and the solid black baffle. This speaker cabinet was designed to have minimal effect on the outbound sound from the drivers and rear port, which measures five inches across. Each enclosure weighs 165 pounds, including the drivers. I would call the Pass SR-2 a medium sized tower, at 42 inches tall, and fairly compact in width, about 16-inches. Front to-back dimensions are 24-inches.

  The speaker connections are bi-wireable, or you can use them with the supplied jumpers. I tested them with the jumpers engaged and with Westlake bi-wire cables.

  The SR-2 contains two tone-tailoring adjustments: rotary-detent, attenuation controls for the tweeter and a woofer, located on the back panel. The tweeter control has three positions: -, flat, and +. The bass has the same adjustments.

  The Pass literature on this speaker does not reveal level changes, in dB, when using these controls, but it appears to be 3-dB steps. In my room, I left the controls in their “flat” position. In a heavily carpeted room with soft furniture you might turn the tweeter switch up to +. Similarly, a reflective room may benefit from the minus position. Bass attenuation via the control could compensate for boomy rooms or less than ideal placement. It’s best to play around with the controls to see what you prefer.

SRT-2: a perfect mate for most any Pass amp

  The SR-2 comes with removable grill that give it a look of refinement, but sonically, I prefer listening with the grill detached. It is slightly more present and real sounding to my ears. Again, it’s my preference, in my listening room.

  The overall system frequency response is rated at 35 Hz - to 20 kHz, minus -3 dB on the bottom end. Using an AudioControl RTA, I measured better than rated spec at about 32 Hz in my listening room, the -3dB point. The nominal system impedance is 6 ohms, Sensitivity is not overly high, but a respectable, 86 dB, 1W/1meter. That is why you have all those watts, right? In reality, a 30-watt amp can drive this speaker to ear-shattering volume in typical listening rooms.

  The SR-2 and its big brother, the SR-1 4-way, which uses a two-enclosure, stacked arrangement, were designed, according to Pass, to carry on the Rushmore tradition of fine, accurate sound in an elegant enclosure. The speaker line also address the desires of Pass amp owners who wanted a new speaker to call their own. I would say that Nelson Pass and company achieved their goal, but the speaker has a much wider potential audience. As I discovered, the SR-2 can work with most any amplifier.

The setup 

  I placed the speakers in my audiophile listening room about 8 ft. apart and 7 ft. from the back wall. They were angled in, per the Pass manual. I used various amps from my collection, including two Pass amps: the X350.5 Class A/B MOSFET and the ever-versatile XA30.5, all Class A super symmetry MOSFET. I also mated the SR-2s with the highly regarded Rogue Audio Medusa Class D/tube hybrid amp, a Bryston 14B SSTII, and a vintage 1960s Macintosh MC275. For kicks, I also plugged the speakers into an AudioControl AVR-4 Class H receiver — one of the better multichannel all-arounders out there, but also a pretty good stereo playback component. (click here to see the review on EAN).

  The audition preamps included the Coda High Current, the Rogue Audio Model 99 tube pre, and a Pass Labs XP-10 preamp. I used WireWorld interconnects for balanced and unbalanced termination, and Alpha-Core Goertz solid-silver, flat two-conductor speaker cables for uni-wire and the Westlake Audio bi-wire cables.

The first thing I noticed with the SR-2s was how clean the bass was, even with the five-inch wide rear port; the bass has a tight, almost acoustic suspension character. The bass drums and the organ’s chugging low-end girth were clear and defined.

  Source gear included the Oppo BDP-105 universal player and Macbook Pro with Audirvana playback software for high-res download playback. The Mac was connected to either a Benchmark DAC2-D or Mytek Stereo192 DSD D/A. Record duties were handled by my Clear Audio turntable and an AT-150ML cartridge.

  As typical in my test setups, all components were linked to the AC through Essential Sounds Products Essence II power cords and power strip that are clean as a whistle, in terms of noise rejection and current delivery

  Though the speakers don’’t look that big, the SR-2 are stout. The MDF cabinet, plus heavy duty drivers and electronics, contribute to a 160 pound+ package that is quite heavy to move around by yourself. After doing the tippy-toe dance in their shipping cartons, I got them down two flights of stairs to my basement audiophile room. I carefully unpacked them from their foam packing material, slid them into position, and adjusted the feet to get the tweeter close to ear level.

  Pass Labs President Desmond Harrington said the tester SR-2s had been given a mild break-in before leaving the factory, but I plugged in an old CD player and played, on repeat, a test tone CD for three days to further burn in the drivers.

The audition

  Firing up the Pass Labs X350.5 amp, my listening tests began with a lengthy listening session with one of my favorite jazz recordings, the Anthony Wilson Trio — Our Gang SACD (Groovenote GRV1008-3), now out of print. Using the Oppo BDP-105, this is a well-recorded, minimalist, direct-to DSD recording of Mr. Wilson’s fine Gibson jazz guitar playing, Joe Bagg on Hammond B3 and Mark Ferber on drums. The 2001 recording has a warm bass character, yet energetic top-end with ever-present drum cymbals, intricate guitar picking and that thick sound of a Hammond tube organ with Leslie.

  The first thing I noticed with the SR-2s was how clean the bass was, even with the five-inch wide rear port; the bass has a tight, almost acoustic suspension character. The bass drums and the organ’s chugging low-end girth were clear and defined. I think the ultra-rigid cabinet construction also contributes to this clean-bass character.

  The midrange tones were quite accurate, not overly forward or recessed, while the top-end beams a smooth, analog-like presentation. No metallic-tweeter artifacts or the narrowness of some ribbons that I have auditioned.

  Some audiophiles may perceive the treble as a touch laid back, but the more I listened, the more it sounded balanced and accurate. If you want to punch up the treble presentation in a “dark” sounding room, you can turn the SR-2‘s tweeter attenuation switch to +, which adds a tinge of shimmer. But if your room is not heavy in fabric and you have normal upper-frequency reflections, the switch’s flat position is just fine.

This speaker offers a no-hype, high-caliber transmission of sonics that is old school smooth and gimmick free. It relays high-resolution music with a keen accuracy and much welcome, tight, deep bass from its port-assisted cabinet. As I discovered during the review process, it matches well with Pass’ own amps, as well as various other amp designs.

  Moving onto the Warren Bernhardt - So Real SACD, recorded by Tom Jung in 1999, the SR-2 sounds terrific on the piano interludes, showcasing that fine Steinway grand used in the recording; the upper register notes were natural  — without any of that ringing I sometimes hear with cheap metal-dome tweeter speakers — and I could hear the room reverb decay quite clearly.

  On classical music, the Pass SR-2 midrange quality was obvious — with a thoroughly enjoyable listening session with Janos Starker - Bach Cello Suites SACD. The sweet cello tones were spot on through the Pass speakers, projecting a rich, velvety texture and plenty of string harmonics. Again, these SEAS drivers were fatigue-free, yet detailed in their relay of the cello. The SR-2 pair were equally at home with violin recordings, never descending into that edgy, ragged tone that you hear with over-hyped speakers.

  To check out the bombast of a spirited orchestral work, I played the Telarc SACD transfer of Tchaikovsky - 1812 Overture, recorded in  1978 with Eric Kinzel and the Cincinnati Pop Orcestra. Though a 16-bit PCM recording using the Soundstream recorder (popular in the early days of digital), the dynamic range is vast — ranging from low-level instrument solos to the full-tilt power of the Cincinnati Pops Orchestra and the overdubbed cannon shots that all build to a crescendo. At 90 dB plus levels, the Pass SR-2s never showed any strain through the X350.5, or any of the other amps. Although not reaching the depths of a subwoofer, The SR-2 relayed the cannon shots quite well — with substantial sub 40-Hz impact.

  Compared to my Legacy Focus 20/20s and the MartinLogan Montis electrostatics, the SR-2s imaging held its own. The MartinLogan electrostatic dipole is the king of soundstage width and depth, creating amazing space between instruments. As a traditional three-way, the Pass SR-2 is not quite in that league, but is surprisingly wide in its stereo projection for a narrow tower speaker, offering good depth front to back. I think the tight bass also contributes to its ample musical space impression.

I did a lot of repeat listening of the music on my other amps, and the SR-2’s essential character was maintained. The Rogue Audio tube/Class D MOSFET was slightly leaner, the Bryston 14B SST II split the two, and the Pass all-Class A XA30.5 tilled toward slight warm.

  For those who love vinyl, the SR-2s will not disappoint you. Via my Clear Audio turntable, the attached AT150ML cartridge, and preamplification through the Rogue Audio Model 99 tube pre with Magnum phono stage, my half-speed mastered Wes Montgomery - Full House reissue was delightful. Montgomery’s amazing, thumb-picked Gibson L5, and the open, live analog recording from the early 60s, projects an immediacy that only vinyl and analog tape can convey. I really dug that sound when listening to the Pass SR-2s. The combination of the AT’s accurate-as-you-can-get-from-a-phono-cartridge sound, and the tight, present demeanor of the Pass SR-2s, made for a blissful record-listening experience.

  On pop music, the SR-2s immersed me with their smooth, focused bass and open, top-end. The Neil Diamond — Hot August Night reissue double CD, one of the best live recordings from the 70s, sounded aces. The speakers highlighted  the analog recording’s broad presentation of Mr. Diamond’s many talents: from faux country (Your So Sweet, Kentucky Woman), hard rocking, (Crunchy Granola Suite) and big tent pop/gospel (Brother Love’s Salvation Show/Soloman). This album kicked butt through the SR-2s.

  For the grittier, bluesy side of the spectrum, I popped in my Stevie Ray Vaughn/Albert King - In Session SACD. The overdriven guitar tone and gritty vocals cane through with all of their colors intact. The digital recording never got hard or edgy with the SR-2s. On dense, dance-pop/hip-hop music, the SR-2’s bottom-end control makes the music more listenable versus some bigger towers that I have tested. One of 2013‘s biggest singles was Daft Punk’s “Get Lucky.” Its vintage Chic vibe with plump bass line and Nile Rogers guitar rift, is infectious and gets full play from the Pass SR-2s. Heck, I even put on my vintage copy of Chic - Risqué, the vinyl record version, (yeah baby, 1979). The SR-2 pumped out the dance floor vibe with that signature rhythm guitar, bass and female vocal lead just fine.

Pass SR-2 tweeter attenuation switch

  Speaking of vocals, compared to the many forward-voiced speakers that proliferate the audio landscape, today, the Pass SR-2 does not have an aggressive mid character, This can make voices, depending on the recording, sound slightly more subdued in comparison, but I think it is mostly is the reference point of other speakers that exaggerate the mids. The SR-2's vocal clarity and its tonal balance is more like the real thing. By the way, The SEAS tweeter does a magnificent job of dampening down sibilance and upper-spectrum resonances, especially with female voices.

  I did a lot of repeat listening of the same music on my other amps, and the SR-2’s essential character was maintained. The Rogue Audio tube/Class D MOSFET was slightly leaner, the Bryston 14B SST II split the two, and the Pass all Class A XA30.5 tilled toward slight warm. The old Macintosh MC275 tube amp, coupled with the Rogue Model 99 tube pre, conveyed an ultra-vintage, soft bass, laid-back tone that was nice on instrumental jazz and classical, but plumped up the bass with pop music. Time to turn down the woofer switch.

  Just to show that all roads are not paved in separates, a bit of time with the AudioControl AVR4 Class H receiver convinced me that it was an unusual, but nevertheless, a good mate to the Pass SR-2s. The audiophile-grade receiver (it costs about $6,000) relayed the 2L Blu-ray classical violin concerto, Ole Bull — full of string harmonics and a spacious stereo image — without a hint of edginess. Several friends commented that they thought the music was coming through separates, not a receiver. It is quite a testament to the AVR and the SR-2s.

The verdict

  Having reviewed quite a few Pass products since the late 1990s, I was not surprised that the Pass SR-2's performed so well. With the original Rushmore as its inspiration, and Pass’ dedication to high-end quality hi-fi, the SR-2 is as fine loudspeakers as you could buy out to about $40,000. Its accurate, yet musical, tonal spectra, classy build and good looks net it a Stellar Sound Award. The SR-2 is not the cheapest speaker, but also is not the most expensive either. If you have $18,000 to spend, a pair of Pass Labs SR-2's is worthy of consideration. In the high-end priced world, they may be a bargain.

  John Gatski is publisher/owner of the Everything Audio Network. ©Articles on this site are the copyright of the Everything Audio Network. Any unauthorized use, via print or Internet, without written permission is prohibited.

Audiophile Preview!Exclusive First-Listening Sessions:Benchmark AHB2 Stereo Amplifier

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Price: Estimated $3,000+

Likes: digital-like specs from analog amp

Dislikes: not in production yet

More info: Benchmark AHB2

by John Gatski

  Benchmark Media has been in the audio game for more than 25 years. And although they are best known for their DACs and ADCs, they have never been afraid to delve into new areas of product development. So the recent introduction of the new audiophile stereo amplifier, the AHB2 was a nice surprise but not totally out of left field. In fact, the company’s founder, the late Allen Burdick created a high-quality amplifier back in the 1980s, the DA101 distribution amp that was highly regarded for many years.

  The new compact AHB2 however, is a new design that takes amplification to another level in terms of measured specifications. In fact, the performance of this new analog amp rivals the measured performance of its world class DACs. The amp is slated for dealers in early January 2014.

The AHB2 design

  According to John Siau, Benchmark’s chief designer and VP, the Benchmark AHB2 is a unique amplifier that was designed in conjunction with THX. The bipolar-output, 100 WPC RMS analog stereo amp (350W bridged mono) is housed in a compact enclosure that measures two times a DAC2 (11" W x 9"D to back of connector x 3 7/8"H). Despite its modest proportions, the AHB2 boasts numerous design highlights that enable it to deliver measured specifications as good as its digital converters, especially its noise and dynamic range performance.

  “It was my goal to create a power amplifier that matched the performance of the DAC2 D/A converter,” Siau explained. “After all, the performance of the D/A converter is only useful — if it can be delivered by the downstream power amplifier.”

  I applaud Benchmark’s efforts to clean up analog amplifier noise. That low-level idle hiss that I hear from numerous vintage and modern amplifiers is, at the very least, annoying, and, at its maximum, detrimental to ultimate resolution.

  Siau said that the amp has exceeded his expectations in terms of measured performance. The SNR of the AHB2 was spec'd at 126 dB (A-weighted) and THD is -115 dB, just about as good as the DAC2’s measurements. “The AHB2 power amplifier was designed from the ground up to deliver the full performance of the DAC2 HGC," he emphasized.

  Siau furnished me with an Audio Precision System 2 measurement of the prototype AHB2 that I spent a few days with recently. The dynamic range was -130 dB, A-weighted! I don’t think I have ever seen (or heard) a hi-fi amp with such specs. Back in the 1980s, I remember sold state amps with a typical -85 dB dynamic range/noise spec.

  In order to achieve the new spec, Siau utilized THX amplifier design concepts, as well as applying some of his engineering prowess in order to get these impressive numbers, and as I found out in my brief listening sessions, impressive listening results.

Digital specs, analog amp

  Siau said the following design highlights enabled Benchmark to create the AHB2’s “fantastic” performance signature.

•Low gain (9 dB). This allows +22 dBu input at amplifier clip, which is essential for low noise;

•Patented feed-forward error correction, which virtually eliminates crossover distortion, a problem Siau says is still common among typical amplifier designs;

•The feed-forward design also makes bias currents unnecessary, and non-critical. Thus, Class B operation is possible with very low distortion;

•The multiple bipolar output stages are run in parallel to eliminate crossover distortion; one output stage is active, while another is in the crossover region;

•The Class AB output stage uses very low bias current. (Due to low bias currents, idle power consumption is only 20 watts.);

•The feed-forward design even makes the more efficient Class H or G operation possible — with no rise in distortion at class H or G switch point (Class H , or G, rail switching at a 1/3 power threshold);

•A tightly regulated power supply — with high-bandwidth control loop on the switch-mode power supply — responds to amplifier loading over the entire audio band, and at ultrasonic frequencies;

•The amplifier does not rely on capacitive energy storage, and the switch-mode power supply eliminates AC line magnetic interference to levels not possible with a linear power supply

•The AHB2’s greater than 200 kHz bandwidth allows it to achieve excellent inter-channel phase at 20 kHz and greater than 0.1 Hz low-frequency cutoff is said to minimize low-frequency phase shift;

•The feed-forward design also improves damping factor for improved bass response, and the PCB uses balanced star-quad signal and power supply distribution to minimize magnetic interference.

**Siau said that certain THX design elements allow him to make the amp as efficient as possible, but the AHB2 design was optimized for low distortion and low noise.

As I got into serious listening of recordings, I was impressed by the AHB2’s "smooth factor. Although it uses bipolar output devices, its tonal delivery ease reminds more of MOSFET designs. Drum cymbals and the upper register of the Bernhard album’s piano sounded fantastic without any edge, grit or harshness. 

  “It was not optimized for the highest possible efficiency that could be achieved with the new THX topology”, Siau explained. “Nevertheless the AHB2 is much more efficient than a conventional Class AB design. Peak power does not vary with AC line voltage (due to the regulated supply). Likewise, power drawn on one channel does not influence the power available from the other channel.”

**Though the ABH2 utilizes a switching power supply, Siau emphasized that the overall amp design is not a switcher. “The AHB2 is a linear amplifier, it is not a switcher,” he noted. “For this reason, it produces very little out-of-band noise. The A-weighted noise is only 2 dB less than noise measured over an 80 kHz bandwidth. This was an important design goal because ultrasonic noise can be folded into the audio band by the non-linearities in speaker transducers.”

The ins and outs

  Siau sent me one of two ABH2 prototypes to conduct a few days of subjective listening in late October. He said that there would likely be a few more tweaks in the final version, but the prototypes represented the essential sonic signature of the design.

  The ABH2 is a simple amp to operate. It includes a front power on/off switch, binding posts (final version will have binding posts with easier access than the prototype’s horizontal-aligned speaker inputs), balanced analog inputs and a 12V trigger input.
  You can also bridge the amp to mono, via a rear toggle panel switch, to get 350 watts (8 ohms). Thus, buying two stereo amps and bridging mono for each one would be the chosen path for powering the less efficient speakers, or filling big rooms.

Production AHB2 will get optimized conection access

  Since the amp is not a high-gain amp, ensuring gain match with your source preamp is a consideration. The Benchmark DAC2 HGC and DAC2 D have enough gain in the stock setting on various audiophile recordings. However, if you move a jumper inside the DAC you can get 10 dB more gain to give extra headroom.

  I played around with various gain components during my time with the AHB2, including the Coda preamp, Oppo BDP-105 variable balanced output, and the DAC2 D's variable output.
  The Oppo BDP-105’s variable or fixed output, even at full blast, was just enough gain, but not ideal  Benchmark’s Siau said that the production AHB2 will have three gain settings (with virtually the same noise spec), and offers more flexibility for preamp choices than the single (low-gain) setting that was active on the prototype. “This (three-position gain level switch) makes the AHB2 compatible with all preamplifiers, but preamps that do not have high output usually have a poor signal-to-noise ratio, and will, therefore limit the system performance.”

  Like the Benchmark DAC2 D, the Coda preamp was a better fit than the Oppo’s variable output. It had to be cranked a few more clicks on the volume control to get to the level of my normal amps, but they were still able to drive the Benchmark to plenty loud levels without noise.

For those who listen with very accurate, discerning speakers, an extra 20 dB of lower noise could be heard — in terms of ultra detail that may be hiding in the noise of an average audiophile amp.

  Sources for the AHB2 listening sessions included the Oppo BDP-105, Benchmark DAC2 D, TASCAM DVRA1000 HD master recorder/player, and Apple Macbook Pro feeding a Mytek Stereo192-DSD DAC. Preamps included a Coda, a Pass Labs XP-10 passive preamp, Rogue Audio Model 99 tube preamp, and the line output of the Bryston BHA-1 headphone amplifier.

  Speakers included the Pass Labs SR1 three-way towers, MartinLogan Montis electrostatics (though the bass is handled in the speaker via a sealed powered subwoofer), Westlake Audio Tower 6, the best sounding Westlake hi-fi speaker and a pair of Westlake LC 8.1's and the ever-popular Legacy Studio stand-based small speakers.

  All interconnects were furnished by WireWorld. Speaker cables were courtesy of Alpha Core; Essential Sound Products provided the AC distribution gear including the Essence II passive power strip and several Essence II power cords that give clamp like connection to the wall and low-noise shielding.

A brief audition

  The AHB2 was first mated to the Pass SR1 tower speakers, the company’s entry -evel tower, which is an excellent three-way (review in just a few weeks) with quick, deep bass and silky top end.

  First up was the Warren Bernhardt — So Real SACD, a recording that has a full dynamic range and spacious soundstage with piano, drums and bass. I connected the Oppo BDP-105 XLR balanced output to my CODA preamp. Because of the prototype amp’s low-gain only setting and a Benchmark caution that preamps need to have abundant gain to drive the amp, I was curious as to how the various preamps would fare.

  Because the Bernhardt recording was recorded live-to-two tracks, its vast dynamic range is quite apparent, which means the quiet parts are quiet, and the louder parts are, well loud; thus, if you want to hear it loud, especially the softer parts, you got to crank it up a bit with this amp.

  I am happy to report that the Coda’s gain structure matched up well with the AHB2. I had to turn it up a few more clicks on the volume control, but there was plenty of level without noise.

  The first thing I noticed with the AHB2 is the lack of idle noise. Put your ears to the tweeter and none of the low level hiss you hear with conventional, high-gain amps can be heard. With no signal, nary a whisper from the Benchmark even when cranking up the CODA (or other preamps as I later discovered).

Pre-brochure AHB2 Specs

  As I got into serious listening of recordings, I was impressed by the AHB2’s "smooth factor. Although it uses bipolar output devices, its tonal delivery ease reminds more of MOSFET designs. Drum cymbals and the upper register of the Bernhard album’s piano sounded fantastic without any edge, grit or harshness. The dynamics of the So Real recording jumped out at me when listening to the AHB2 — with a deep, wide stereo image and an encompassing presentation of the subtle layers of each instrument and their ultimate interaction with each other. This quality was repeated through numerous other recordings as well.

  On the Gene Bertoncini — Body and Soul SACD, the warm, percussive guitar tones shone with this amp producing a wide spread of plucked notes. The low noise floor of the AHB2 however, was swallowed up by the recording's tube mic noise, but still the expansive stereo image and nylon string guitar’s dynamics were up there with the best amps I have auditioned.

  Switching to the MartinLogans and using the Benchmark DAC2 D D/A as a preamp with high-res PCM digital sources, the AHB2 again revealed its dynamic, clean, quiet character. The exquisite layers produced via the MLs were even more in evidence with the AHB2. The Tuck and Patti — With Love CD has a unique blend of vocal and guitar interplay that is mixed in a focused, yet open character. The Benchmark brings out the quick, percussive guitar attack with amazing clarity, but no over-the-top edginess that lesser bi-polar (and even some MOSFET amps).

The DAC2 and AHB2 make a dandy pair

  As impressed as I was with the perfectly proportioned midrange and top-end and the spacious layers of detail, the prototype AHB2 did exhibit an occasional denseness when playing mid bass-tinged pop music compared to the other amps driving the same speakers. I do not hear this plumpness with my demo amps, such as the Pas X350.5 or the Bryston 14BSST-II, or the ultra accurate Rogue Audio Medussa digital tube/hybrid.

  Being that it is the first complete prototype of the Benchmark AHB2, I am not worried about the midbass prominence I heard in the brief audition. I am sure Mr. Siau will have this amp in fine form when the production units hit the dealers in a couple of months. In addressing my notes regarding the bass performance, Siau said “there are, in-fact, numerous improvements coming in the next revision. We have revised the Zobel network, over-current protection, power supply, and input sections, just to name a few of the changes.”

Is noise a noise, if you can’t hear it?

  In discussing Benchmark’s impressive amp specs with several audio industry insiders, several of them questioned the necessity of an ultra low-noise floor/ultra dynamic range in the amplifier chain. Does it matter if there is some idle hiss after the music starts to play? And can one hear the enhanced quietness versus an amp that measures, say -100 dB?

  I look at it this way: line sources, DACs, players, etc. have exhibited generational improvements in measured performance, and I believe these improvements have brought progressive audible, if subtle, improvements as well. For those who listen with very accurate, discerning speakers, an extra 20 dB of lower noise could be heard — in terms of ultra detail that may be hiding in the noise of an average audiophile amp.The -130 dB noise/dynamic range  just gets us that much closer to the live music signature that we yearn to hear from our beloved electronics.

  So, at the end of the day, I applaud Benchmark’s efforts to clean up analog amplifier noise. That low-level idle hiss that I hear from numerous vintage and modern amplifiers is, at the very least, annoying, and, at its maximum, detrimental to ultimate resolution. I can’t wait to hear the final version of the AHB2.

  John Gatski is publisher/owner of the Everything Audio Network. ©Articles on this site are the copyright of the Everything Audio Network. Any unauthorized use, via print or Internet, without written permission is prohibited.

Speaker System Review!Paradigm MilleniaOne CT Powered 2.1 Speaker System:"Super Sound In a Small Package"

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Price: $1,199 retail

Likes: impressive full range accuracy

Dislikes: that tiny remote

More info: MilleniaOne CT

by John Gatski

  I have evaluated more than 120 different speakers in the last 23 years that were designed for specific listening tasks, but few equal the versatility of the Paradigm MilleniaOne CT sub/ mini-monitor system. The key to this trio of speakers is the small main speakers coupled with the compact-sized, innovative subwoofer that kicks out substantial bass performance. It was shocking how good these speakers perform.

Features

The MilleniaOne CT System, priced at $1,199 retail, includes two mini-main speakers — in a two-driver arrangement, 7-inch tall die-cast enclosures. The 1-inch S-PAL satin aluminum dome delivers the high frequencies, while the 4-inch S-PAL woofer handles the bass duties down to about 135 Hz. The third-order crossover frequency is centered at 2.4 kHz. Factory rated response is 135 Hz to 20 kHz (+,- 2 dB, on axis). The rated sensitivity is 88 dB, 1w/1meter.

  The powered subwoofer is the heart of the system — with bass crossover, connections and amplification housed in a narrow, sealed enclosure (measuring 14 -inches x 5-inches x 12-inches). The woofer is uniquely shaped, at 14-inches by 3-inches and moves a substantial amount of air, claimed to reach down to 26 Hz at its -3 db point.

  Power to the system is housed in the sub’s digital amp section — with a rated 100-watts RMS to the sub and 50 watts each to the main speakers. Peak power is 600 watts total. The fixed crossover is 150 Hz.

  With computer audio in mind, the MilleniaOne CT sports optical digital and stereo mini-jack analog connection. As good as the system is, I wish it had RCA inputs as well. The onboard DAC only delivers 24 bit/48 kHz. Thus, if you want to listen to 96 kHz or higher audio with MilleniaOne, you need to do it via the analog input.

  If ever there was a product deserving of the EAN Stellar Sound Award, it is the Paradigm MilleniaOne CT speaker trio. Its accuracy, ample power and myriad uses make it one of the few audio products that cuts across all audio niches.

  The MilleniaOne CT system also includes standard accessories: speaker wire to connect the subwoofer to the satellites, desk/stand mounts, wall brackets and an optical digital cable and an analog RCA-to-mini-jack. A mini remote control contains volume up/down buttons and input selection.

  Paradigm offers a number of optional accessories (floor stands, etc.) and other MilleniaOne CT speaker configurations. You can buy additional speakers by the pair at $499 retail. Paradigm even offers a center channel/L/R speaker trio for $749.

  The MilleniaOne CT has numerous potential uses. Besides a clean, accurate living room stereo playback, it can be used as a computer playback system, TV playback system, a bedroom or small den listening station. If you purchase three more of the satellite speakers ($749), it becomes a dandy, space-saving 5.1 system for home cinemas in small-to-medium rooms. Of course, the standalone MilleniaOne main speakers need their own power, so you would have to supply the amp or receiver to power them.

  Or you can rely on the MilleniaOne CT trio as a kick-ass, mini-audiophile system that projects accurate sound way beyond their diminutive size. I put it to work as a stereo monitor system for my home professional recording rig, using a Benchmark DAC2 D/A or Resonessence Concero HP D/A analog outputs as the sources. I was able to listen to my recordings, do my edits, etc. via my digital software, including 24-bit/192 kHz, DXD (24/352) and DSD.

  You also could set up the MilleniaOne CT system as an outdoor speaker system (though not permanently mounted since it is not weather proof) and liven up your patio party; I could also see it used as a full range a presentation system for business; needless to say, the potential uses are many.

The set up

  I first installed the MilleniaOne CT in my audiophile room. The desk/stand mounts attached easily, and I placed them on my Apollo speaker stands. I connected the RCA line outputs from a Benchmark DAC2 D/A converter, using audiophile WireWorld cable that plugged into a mini-jack-to RCA input, inserted into the MilleniaOne CT analog input. An Oppo BDP-105 provided the source audio. Other applications included recording rig, TV speakers, bedroom system and living room playback system with B and W Mini-Zeppelin iPod dock.

  The included zip cord speakers cables route the audio to the main speakers. The included cables are 12 ft. in length. (If you use the speakers without the subwoofer, you can use really good cables).

The audition

  Upon the first notes of Warren Bernhardt - So Real SACD (DMP), I could tell the MilleniaOne CT is a serious little speaker system. The little guys delivered a deliciously deep and wide soundstage and the tweeters handled the upper register of the Steinway piano with surprising precision. Drum cymbals were open and present — with just a hint of crispness, but not harsh. The subwoofer kicked out prodigious amounts of bass guitar with out any flab or slowness. Damn, this system is good.

  For you picky classical music lovers, I am happy to report that the Paradigm’s MilleniaOne CT tonal qualities are quite clean and flattering. Violin tone, for example, was exceptional from a Mozart - Violin Concerto in D that I downloaded in the DXD format (24 bit/352.8 kHz sampling) from the 2L label and played through the Resonessence Concero HP DAC via Audirvana software on an Apple laptop. On playback, a lot of the violin’s resonant textures that I hear through my MartinLogan Montis and Legacy Studio speakers, were maintained with the MilleniaOne CT system. Again, I was really impressed with the imaging.

Uniqie shape of MilleniaOne CT subwoofer

  To prove my point about the MilleniaOne CT’s versatility, I connected the Paradigm’s to my Sony HX929 Bravia LED TV. Since it has no analog connections, I plugged the TV’s optical output to the MilleniaOne CT inputs. These new TVs — with amazing video quality — are so thin that good speakers are a rarity, thus, a secondary speaker system is key to quality sound.

  I am happy to report that the MilleniaOne CT system ratcheted up the TV viewing experience about 300 percent over the stock LCD tiny speakers. Better vocal clarity, increased music soundtrack accuracy and way more bass were delivered via the Verizon Fios HD TV channels and from Blu-ray and DVD. And unlike a soundbar, you don’t need to worry about placement of one large speaker. I simply placed the satellites on the sides of the TV stand and put the sub on the floor on the left side. I took a snap shot of the speaker/room response with my RTA, and I measured nearly flat audio response from 40 Hz to 20 kHz in my home theater room.

  Moving on to computer source playback, I placed the MilleniaOne CT mini-speakers on either side of my Apple laptop and the subwoofer under the desk. I worked with my own 24-bit/192 kHz sample rate jazz guitar and acoustic guitar recordings through the Apple Soundtrack editing/playback system. Again, the MilleniaOne CT speaker delivered the goods. The acoustic guitar cuts were very accurate, and the stereo recording image was full and detailed. The speakers also delivered good response off axis.

  I am happy to report that the MilleniaOne CT system ratcheted up the TV viewing experience about 300 percent over the stock LCD tiny speakers. Better vocal clarity, increased music soundtrack accuracy and way more bass were delivered via the Verizon Fios HD TV channels and from Blu-ray and DVD.

  On a rock recording that I was editing, the MilleniaOne CT’s accurate bass performance was much appreciated. When I first monitored the music via headphones, I thought the midbass was too heavy and was planning to EQ down the 120-Hz slice of the audio. However, on playback through the Paradigm, I found the midbass rise that I had heard was more the exaggerated bass characteristic of the headphone and not the recording. The MilleniaOne CTs delivered the tracks with a more accurate, cleaner bass, and this was later confirmed by playback on my Martin-Logans.

  Overall, i had no problems with the operation of the MilleniaOne CT system. It was easy to attach the stands, connect the cables and play. My only niggle is the small remote control; it is very small and easy to misplace, I did so several times. The other complaint is a lack of RCA input jacks. It is nice to have the mini-jack for connecting to a computer, but the larger jacks accommodate better cables.

The verdict

  If ever there was a product deserving of the Everything Audio Network Stellar Sound Award, it is the Paradigm MilleniaOne CT speaker trio. Its accuracy, ample power and myriad uses make it one of the few audio products that cuts across all audio niches: audiophiles, home theater and home recording, computer audio. Whatever the use, this compact monitor system delivers the sonic goods. Nicely done, Paradigm!

©Articles on this site are the copyright of the Everything Audio Network. Any unauthorized use, via print or Internet, without written permission is prohibited.

Retro Recording Review!A Classic Benchmark in Microphone Accuracy:The Shure SM81 Small-Diaphragm Condenser

Brevis...

Price: $436 retail

Likes: Accurate cardioid pickup

Dislikes: Omni capsule no longer made

More info: Shure SM81

by John Gatski

  If ever there was a gem of a recording microphone it has to be the SM81. Introduced in 1978, this compact cardioid has carved its reputation as a quality recording transducer for almost any instrument — from piano to drums, overheads to acoustic guitar and classical stringed instruments. Countless recordings have been done via the SM81, yet it often does not get the attention of more famous mics, like the Neumann U47 or even Shure’s ubiquitous SM57.

  The SM81’s main asset is that it has a very accurate frequency response. Unlike many of today’s instrument mics that have various boost curves in the treble, the SM81 is almost flat, varying but only a dB in the high midrange/low treble range. This response is perfect for those recording projects where you don’t want a boost, cut or any other response tailoring via the electronics. That is why numerous engineers have used the SM81 as drum cymbal overheads; the response is smooth and natural without the splashiness of mics that are hyped up a few dBs in the treble.

Delightfully simple...

  The small-diaphragm, cardioid-pattern, electret condenser SM81 has continually been in production since the late 1970s, when it originally sold for $200. Today, it sells for $436. Originally, made in the USA, the SM81, like many Shure mics, are assembled in its Juarez, Mexico plant. It is now  It has been refined over the years to lower its noise floor and once was available with an optional omni-directional capsule. The body dimensions also have been altered slightly — with the older versions tapered toward the termination end and the later versions symetrically round from one end to the other. The SM81  features a three-way bass roll-off switch (O dB, -6 dB or -18 dB per octave at 200 Hz) and an attenuation switch (O dB, -10 dB).)
  The mic is a bit longer than many smaller, modern instrument condensers, at more than 7.5 inches, but it comes with its own mount (and wind screen) that attaches easily to a T-bar stand or other typical mic mounting devices. BTW, the SM81s are so consistent in spec that Shure does not have to level match. They are usually very close in output right out of the box.

Amazingly flat frequency response with the bass roll-off disengaged

  As mentioned, the key to its sonic signature is the flat frequency response. If you look at the factory response graph, it varies only 1 dB at any point from 50 Hz to 16 kHz — an amazing spec. that many of today’s microphones don’t mimic. In that crucial 5 kHz to 10 kHz range, the response is almost ruler flat. If you have a neutral recording space and you like the sound of the instruments, this sonic accuracy makes for a truer recording that is especially appreciated when recording in high resolution formats. The defunct omni-directional capsule option retained the cardioid’s accuracy, but offered more of an open recording pattern to pick up more of the room. The omnis are highly sought after today.
  The knock on the SM81 has been its self-noise spec. In fact, over the years there have been modifications made through third parties to lower its noise. The original spec was 17 dB self noise, which was later lowered to 16 dB A-weighted. Most of today's small condensers are a few dB quieter, but in the real world, I really don’t notice any extra noise — even in 24-bit.

Presence enhancement, courtesy of the microphone, is not desired when I want an accurate portrayal of my guitars. The SM81 is truer to the guitar’s actual sound in a good-sounding room.

  When I asked longtime recording engineer Tom Jung about his extensive use of the SM81 during the 1980s and 1990s, he said its accuracy was paramount in the early days of digital recording where you did not want any added harshness through the microphone.
 Jung also noted that Shure used to supply him with modified versions (in omni and cardioid) that were several decibels quieter than the stock ones. (Per Shure this custom modification activity is no longer being done). Jung said the SM81 excelled on piano and drums, but he would often use it on all sorts of instruments, including bass and guitar. At one point, Jung remembers having a dozen SM81s in his arsenal.

A fresh take on the SM81
  I recently acquired an SM81 pair from Shure to reacquaint myself with the mic. Since I record mostly acoustic and electric guitar, I went to town, recording several six strings and amp combos. I recorded to 24-bit/192 via a TASCAM DVRA-1000-HD, which was fed by a stereo True P2 discrete mic preamplifier, using WireWorld XLR cables.
  On a custom Guild F47 rosewood edition with red spruce top, I recorded at 24 bit/192, using the True P2 discrete mic preamp. I immediately noticed how accurate the playback was. The Guild sounded like it did live! No enhanced strumming or picked-sound lift in the high midrange and low treble. No presence boost at all. Also, the bass proximity effect was typical of a small condenser in that you could easily control with distance placement. Thus, I did not have to apply any electronic roll-off. The recorded results were similar with my big Martin J-40 and my custom OO-28V finger-style guitar. They sounded exactly like what I hear when someone plays them.

A SM81 manual from the early 1980s

  In contrast, the Audio-Technica 4051B and Shure‘s more recent KSM141 instrument microphone added a gentle presence sheen to the guitar’s treble spectrum — a sound that can match up well with darker sounding guitars and/or rooms. But that presence enhancement is not desired when I want an accurate portrayal of my guitars. The SM81 is truer to the guitar’s actual sound in a good-sounding room.
  I also was quite happy with the SM81s on jazz guitar. My Gibson L5-CES, with twin humbuckers, played through my original Fender Deluxe Reverb, has a warm, bell-like strummed tone that is mostly upper bass/midrange/lower treble focused. In recording the combo with the SM81, its mellow character with a hint of top-end was true to the actual sound of amp and guitar. I also noticed how dynamic the sound was in 24-bit. With the noise of the old Fender (even with a fresh cap and resistor upgrade), any self-noise from the SM81 was not audible.

In the right key...
  I also mic’d up my electronic Nord Electro 3 keyboard, through the ultra accurate Lipinski L-505s loudspeakers, to hear how the Nord’s excellent Steinway mode sounded through the ‘81s. As expected, the sound was exactly like the played-live tone through the speakers: no low-treble tilt in the high register of the sampled piano, a characteristic I have noticed when recording with other modern instrument mics. Again, in my book accuracy is key.
  In light of the hyped character of many mics used today for recording various instruments, some engineers may say the SM81 tone is boring, lacks flair or any character. But that is exactly why I love it. I hope they keep making it forever.

Second Opinion!

Classical Music Recording Engineer

Likes His SM81s, Shure Product Support

  The Shure SM81 is a standard in the audio industry — if ever there was one! Everyone has an SM81 story; here's mine.
  A couple of summers ago, at a music camp in Vermont my daughter was attending, I was asked to check out their four hanging mics for which, it turned out, I had given the original advice about purchasing decades ago. They had a pair of Sony ECM 33Ps, and a pair of Shure SM81s. The Sony’s had been there since I gave my original advice — which was during the mid-seventies; the Shures came a few years after that.
  All four mics were incredibly dusty and had never been taken down from their originally suspended perches in the wooden rafters of this very rustic building. Oh, I should point out that this was a summer music camp, and that the building is vacant, locked up tight, but unheated, every Vermont winter!
The camp director had decided to buy new microphones, and he said I could keep these old "beat-up" mics, if they were worth keeping. Gee, thanks, I guess. So I listened to the Shures and they sounded "okay," but not as good as when they were new. Remember, these mics were over thirty years old, and electret capsules do have a finite life.

The full SM81 microphone kit

  So I sent them back to Shure for repair. A few weeks later, I got a repair estimate, which seemed reasonable, so I submitted my credit card info. A few days later, I received a brand new pair of SM81s from Shure! Now there's a company that stands behind their products!
  Later that year, I managed to pick up a pair of the rare, no-longer-made, omnidirectional capsules for SM81s, which made them that much more useful in my recording endeavors. The omni capsules allow me to record acoustic guitars close up without proximity effect — if that's the sound I want — and I also can record choirs (another standard use for SM81s) using spaced omnis, instead of crossed cardioids.
  The SM81 is a bit longer than your average "pencil," small-diaphragm condenser mic, but it's probably one of the flattest-sounding cardioids ever made. They're really flat down to around 200 Hz, where they start to roll off in the diffuse field; used close up, there's that proximity effect, so you usually don't hear the same thinness you'd hear when used for distant miking.
  In my recording experience, the most common uses for the SM81 is as a pair on an acoustic guitar, or hanging a duo in front of a choir. Their neutral character really shines a light on good vocals and guitar pickers who have quality instruments. Many mics have come out since Shure introduced the SM81, but this 35-year old design is pretty hard to beat for those applications.

—Dr. Frederick Bashour

  Dr. Fred Bashour has been a classical recording engineer for the past 45 years, with recordings released on over twenty labels, including Musical Heritage Society, Naxos and Dorian. His studio, Dufay Digital Music, is located in Western Massachusetts. He holds a Yale Ph.D. in Music Theory and is also an gigging keyboardist. He can be reached via the Everything Audio Network, everything.audio@verizon.net

©Articles on this site are the copyright of the Everything Audio Network. Any unauthorized use, via print or Internet, without written permission is prohibited.