Stereophonic Sound with ORTF

slow shutter photo of  D.C. metro subway train
slow shutter photo of D.C. metro subway train

Location sound can present a variety of challenging obstacles to capturing hi-fidelity sound. The infrasound that a fast moving train creates can become a problem for directional mics positioned nearby. Using the techniques described in my previous microphone isolation post allowed me to maximize the available headroom in my recording. Below, listen to a stereo recording I made of the Washington D.C. Metro train. You will hear the subway train arriving from a far left tunnel, after it stops the doors open in the center, then the train rumbles as it fades away into the far right tunnel. The distinct panning or movement of sound in this stereo recording was captured using the ORTF stereo mic technique. Try a pair of headphones or stereo speakers for a fully immersed experience.

Higher quality versions of this recording are available, as well as custom sound designs/effects.

DeVore Orangutan Reference Loudspeaker System

Common Wave Hi-Fi in Los Angeles Debuted the Devore Orangutan Speaker System

This past Saturday evening Common Wave Hifi hosted the North American Debut of the Devore Fidelity O/Reference Speaker System. These high sensitivity speakers feature a 2 box design. From the Devore Website:

O/Reference A

10” paper-cone woofer with a cast Bronze chassis and an all new woofer motor, fully optimized with a pure AlNiCo magnet, copper Faraday rings above and below the gap, a titanium former, and a machined bronze phase plug resulting in better magnetic and inductive linearity, increased sensitivity, and an order of magnitude lower distortion throughout most of the frequency range.

1” silk dome tweeter loaded by a cast & machined Bronze horn with an all new tweeter motor utilizing a large rare-earth magnet and an underhung voice-coil for increased linearity at lower treble frequencies and higher sensitivity.

.75” silk dome super-tweeter with a cast & machined bronze horn and rare-earth magnet.

Solid machined Bronze port tubes and machined brass input-plate are de-coupled from the cabinet to reduce vibration.

Solid machined Bronze port tubes

O/Reference B

11-inch reinforced aluminum woofer and all-new motor system capable of a massive 2 1/4 inch excursion.

11-inch reinforced aluminum passive radiator naturally tuned below 20Hz in-cabinet with no equalization.

Rigid two-inch thick birch plywood front baffle and solid machined brass input-plate to reduce vibration.

Dedicated 700 watt amplifier and all analog signal path including fully adjustable low-pass crossover, variable phase, subsonic filter, and equalization at 20Hz and 35Hz to tailor response to different room installations.

If you were able to hear this speaker system, please share your thoughts. As mentioned in the comments, the setup was far from ideal and the sound was equally so.

Periodic Audio In-Ear Monitors

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Periodic Audio’s In-Ear Monitors, Mg & Be

Founder and speaker designer Dan Wiggins started Periodic Audio with a focus on portable audio. With a list of credentials that includes transducer design at Sonos and Starke Sound, I was very curious to hear his personally designed single driver IEM (in-ear monitors).

While balanced armature driver IEMs are all the rage (I’ve had a pair for years), Periodic Audio created a simpler design employing a single full-frequency driver without a crossover point. With balanced armature IEMs, you are tuning between multiple drivers for a specific frequency range (think hearing aids), while a dynamic single drivers IEM allow for a more full-frequency response with excellent time-coherence.

These single speaker driver IEMs are available in 3 versions; Mg (magnesium), Ti (titanium), or Be (beryllium). The properties of the speaker drivers, like mass stiffness, and electrical conductivity differ for each metal chosen. In fact a full frequency response chart and specifications for each model can be found on their website. For the sake of this review, I auditioned the magnesium and beryllium driver versions directly connected to an iPhone 6.

Unboxing these IEMs revealed a variety of silicone and memory foam ear-tip size options, adapters for both 1/4 in stereo jacks and an airplane adapter (man those airplanes need updating). I was even told you can experiment with the ear-tips and once you settle on the type/size you like they’ll send you some extra ones- cool customer service. These IEMs are made of polycarbonate with the single driver, port, and hard-wired cable. While I was initially concerned about the build quality with these IEMs, after using them for over 6 months (3 days a week at gym), I am happy to report they are quite sturdy little buds.

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All models include ear tips, 1/4 stereo adapter, & airplane adapter

Mg (magnesium): The entry model ($99) is constructed of 96% magnesium drivers with a N48H neodymium magnet. Everything from the drivers to the volume of the front and rear housing were designed and tooled in-house.

Using the magnesium drivers for some time revealed a favor for mid to higher frequencies, and does so in a way that tips the listener to a revealing top end. The drivers produced an even bass response, but some of the authority and fullness of the deepest bass was bested by the Beryllium drivers. While the mid to higher frequencies are pronounced, I would not call them overtly bright or harsh. Soundstage is decent, but not amazing (yes, I know they are IEM). Articulation of musical attack was good but tighter with the Be driver.

Be (beryllium) ($299): The custom top model from Periodic Audio employs a 100% pure beryllium foil diaphragm with a bonded PEEK surround and N48H neodymium magnets.

Moving onto the beryllium drivers was a major step-up, in every way. Bass became extended and powerful, middle and treble frequencies were better balanced and defined. The control of these drivers allowed for a more intimate sonic view of the mix. The soundstage also had a major benefit from the beryllium driver material- nuanced synth sounds from Herbie Hancock now popped out of hard left and right with piston-like precision.

While headphone amps and DACs will certainly improve these IEM’s sound, I was happy to find they were easily driven by my iPhone 6 heaphone jack/amp.

If I had to knock points to either IEM, it would be the quality and presentation of packaging. While they are supplied with a screw on circular case(cord tangle issues), maybe a zippered pouch would be preferred. A small red dot differentiates right from left ear buds, but man is that dot tiny- can we make it a wee bigger? While it may be obvious I preferred the beryllium driver, let me be clear that the $99 Mg in-ear in no slouch. I recommend taking a listen to each model at the next audio show for your personal preference.

Periodic Audio has managed to bring some thoughtful and musical designs to the in-ear monitor market. This materials based approach offers the consumer options and an education. Real science, real engineers, real transparent.

Anatomy of a Periodic Audio In-Ear Monitor

-happy listening

Toslink Digital Audio & The Lifatec Silflex Optical Cable

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Lifatec Silflex glass optical cable

The transmission of digital audio signals has evolved and improved over the years, resulting in several standard formats for both consumers and professionals. When Sony and Phillips were creating the Red Book CD standard they also included an option for digital audio to be transported between components. While the S/PDIF (Sony Philips Digital Interface) standard was created using coaxial cables (electrical voltages over copper) with RCA connectors, Toshiba proposed a novel solution. Optical light emitted from a red LED was used to create  binary pulses that distinguished digital 1’s and 0’s.

Toslink, or more accurately EIAJ optical, is the standard for using collimated light in the transmission of digital audio. Optical fibers are used as circular dielectric wave-guides that transport optical energy and information.

Early forms of this technology suffered from jitter (phase noise from inaccurate clocking) and data errors or drop outs from bandwidth-limited optical cables. Using digital audio chips with improved clocking and digital inputs aimed at reducing jitter is a good start, but to ensure those binary pulses of light reach your downstream component (i.e. DAC) without error requires a cable capable of delivering the full bandwidth spec of the Toslink standard.

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                                       Lifatec custom machined Toslink connectors

While I use AES digital connections in much of my professional audio work, Toslink optical interfaces are often the only available digital input/output for many consumer devices. Apple TV, Playstation, Roku, and most flat screen TV’s only provide optical outputs. With mixed results from Toslink cables made of plastic, I began researching Toslink cables made from glass fiber strands.

After some digging, I stumbled upon LiFaTeC® GmbH, and their North American partner Lifatec USA. The American firm specializes in using optical borosilicate fibers in lighting and sensing products for the medical market, and since 2000 Lifatec USA has been manufacturing glass Toslink cables in Elbridge New York – named the Silflex glass cables.

To achieve a bandwidth beyond the Toslink spec, Lifatec uses 470 glass fiber optic strands in the Silflex glass cables. These glass fibers are custom built specifically for audio data applications. Keeping these strands in place is a smooth outer jacket that encases the fine fibers called Optisilk. Before terminating the glass strands, the ends are bonded together and polished to a 1 micron optical finish (including the connector ferrule). Then, a custom machined Toslink connector that is both robust and lightweight ensures a tight connection without light leakage.

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Lifatec glass optical cable with mini Toslink connectors on one end (Apple Laptops)

For my testing, a 10 ft Lifatec Silflex cable was used to link digital audio sources with digital to analog converters. I used my Playstation and a Blu-Ray player’s optical output to send digital audio data to several DACs for testing. All of my DACs quickly locked to the incoming signals without a hiccup. Sonically, the sound of the Silflex glass cable was clear and transparent, imparting no sound of it’s own. The most important difference I found, when compared to other optical cables, was the tight fitting connector in the Lifatec cables. I used one optical cable where the manufacturer thought it was a good idea to machine a Toslink connector with an unnecessary amount of bulk, which added weight. This inferior connector (from a popular audiophile manufacturer) would easily fall out of the female Toslink socket, not so with the Lifatec cable.

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The custom machined Lifatec Toslink connector is both lightweight and tight fitting

After spending some time with these cables in my system, it became clear that the Lifatec cable was a well engineered product for optical audio transmission. Fine borosilicate fibers and smooth outer sleeving allow the cable to flex and fit around components with ease. The finely polished ends ensure a strong optical signal, and the robust/lightweight connectors prevent any light leakage. It is rare to find such a well thought out cable with quality in every part of the build. It’s even less common to find these high-end custom designs at real world prices. Without hesitation, it is my pleasure to recommend the Lifatec Silflex cable for all your optical audio connections.

Happy Listening!

Nanotech Systems Japan

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What happens when you disperse nano sized (1-100 nanometers) particles of conductive copper, silver, and gold in deep-sea shark oil? Well, you get a unique product that aims to fill in any uneven gaps with electrical contact points. Think spades, RCA, XLR pins, and Power plugs.

Nanotech Systems Japan has been developing products to improve audio, video, and even automotive experiences for some years now. Beyond the contact points, This company has also designed speaker and power cables with nano particles in a colloidal liquid, More on that in a minute, but first let’s see how this nanotech can be applied.

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Silver nano, half silver half gold mix, and copper nano particles suspended in shark oil

Well, it can be used for just about any electrical contact point. I started off using the silver nano liquid on my speaker cable spades. I was told this would effectively fill in any gaps between the spade and speaker terminal. I also found a use for the copper nano liquid when building power cables and power distribution centers. These nanoparticles (used sparingly) of precious metal ensure that full power transfer is occurring at contact terminals.

I encourage experimentation of application to various contact points in your system. It should be noted that these are enhancers, not cleaners. So beginning with a clean contact is a good start. One experiment I did was with a very worn and noisy guitar cable plug. The solder points were all intact, but for some reason the plug made a noisy connection. I applied the gold contact liquid to the plug and the intermittent noise ceased. Excellent, now to try it in my audio/video system.

As for sonic improvements, these products may indeed help in that area. I recommend that you apply and test for yourself.

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After speaking with Nanotech Systems Japan, I was able to test out fully terminated power cable (Golden Strada) that had been treated with nano particles. Gold and silver nano particles are dispersed in a colloidal liquid, then applied to the full length of conductors in this power cable. In addition, an electromagnetic wave absorption material is also applied to this power cable for reduced interference. This nano liquid, when applied to the full length of conductors may prevent signal jumping -which I suspect is one cause of distortion. See my article on solid core copper vs stranded copper cables.

For my application (audiophile systems), I used this cable to provide power to my power distribution bar (Oyaide MT-UB). I also tested it directly connected to my power amplifier.

With the Golden Strada providing power to my entire distribution bar (which I built with nano copper enhancers) I found a sense of ease and flow to the music which seemed to emerge from a blacker (quieter) background. Initial impressions; Taught extended bass with imaging control. When connected directly to my power amp the Golden Strada truly excelled at bass control/extension and quiet backgrounds.

I especially liked the Golden Strada power cable for picture quality in film. When used for powering a Blu-ray player in my system directly, the contrast and depth of picture was easily improved.

While using other power cables to provide power to my Oyaide MT UB, I found the unique abilities of the Power Strada to shine through when directly connected to my system components. Experimentation is encouraged, and using more than one in an audiophile system will provide varied results – build your own or buy terminated.

Nanotech Systems Japan has created a whole line of DIY products, enhancers, and completed products to improve audio/visual systems. These products are also not excessively overpriced.  If you are ever in the Akihabara neighborhood of Tokyo, I recommend finding some shops that carry these unique science-based audiophile products.

Happy Listening!

Channel Islands E•200S Stereo Amplifier

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Channel Islands Audio E-200S Front Panel

The last time I tried out some of Dusty Vawter’s amps I was toting two hefty monoblock amplifiers down the Pacific Coast Hwy. On this journey, my payload was significantly lighter. The E-200S stereo amplifier box fit snugly into the back of my Subaru, and once home, this small unassuming amplifier took center stage powering my 2 way speakers- Green Mountain Audio Eos HX.

Getting it out of the box, was a snap (14.0”W x 2.75”H x 10.0”D). The size and weight of this amplifier made setup and handling a breeze. While the front panel grants access to an on/off button with blue LED surround, the host of usual connections can be found on the amp’s business end. Whether you choose RCA or XLR inputs, the custom differential input stage is used. Then an updated UcD Class D stage drives the output. Speaker binding posts are insulated and accept spades or bananas, and a trigger input is also made available. Power cable plugged in, and we are off.

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200 watts per channel @ 8 ohms/ 400 watts per channel @ 4 ohms

For music, I used a Macbook Pro running iTunes/Pure Music 3. The DAC was my Crane Song Avocet, and the Antelope Audio Zodiac Platinum. With everything connected via balanced cables and several hours of warm up (this amp had already been burned-in) I was ready to start listening to some of my favorite tracks.

I cued up some acoustic music by Kings of ConvenienceThis Norwegian duo offers a great starting point to evaluate the naturalness of the male voice. Listening to “Rule My World” from “Declaration of Dependence” gave me some lovely acoustic guitars with harmonizing male vocals.

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View from above, notice the small footprint

The two part acoustic picking of “Declaration of Dependence” maintained all the midrange richness while allowing the male vocals to almost float above the gentle picking style. The clarity of guitars and male voices were presented in an un-hyped and natural way.

Moving onto more complex works, I began listening to Herbie Hancock’s “Steppin’ in It.” This groove laden funk from Mr. Hancock’s “Man-Child” album features rich synth leads, a tight bass lines from Paul Jackson, and a stellar harmonica solo by Stevie Wonder. Allowing all that musical articulation to shine through requires some control over loudspeaker movement. The E200-S gripped My Eos HX and allowed each and every bass note to come through with precision and depth. While everyone in the band holds down the groove, Herbie takes the Rhodes for a stroll… and before you know it Stevie Wonder is syncopating a harmonica unlike I’ve ever heard. With each breath, a new note even funkier than the last is pumped out. All these counter rhythms and complex instruments can be demanding on an audio amplifier, and the CI Audio E-200S never slowed down. In fact, the intricate stereo soundstage was expansive. To top it off, the tonality of instruments (even the squeaky high harmonica) never sounded dull or harsh.

To verify the neutrality, I relied on several orchestral and vocal ensemble recordings I made for NPR, all at the same performance hall. While less capable amplifiers have shown some distortions or break-up, I’m happy to report that the CI Audio amp had none of those shortcomings. Localizing mic placement, hall width/depth, and reverb decay were all amplified without coloration. This provided a sonic portal to the original recorded events, an immersive experience indeed.

Spending time with the E-200S was revealing in so many ways. From black quiet backgrounds to fully erupting orchestral performances, this little beast was in control. Most of all, this CI Audio amplifier proves that green design and audiophile sound need not be mutually exclusive.

Happy Listening