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

Crane Song Avocet with Quantum DAC

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David Hill of Crane Song LTD builds some genius pro audio equipment. His mic pre amps and compressor designs have always held a special place in my sonic memory. I’ve been lucky enough to use his gear in broadcast studios and through my own personal music recordings.

The Crane Song Avocet is a Class A monitor controller with a built-in DAC (Digital-to-Analog Converter). Having undergone 5 iterations, the current  Quantum DAC boasts impressive jitter specs and uses a proprietary reconstruction filter for accurate time domain response. Operating asynchronously with a 32 bit architecture, the reference clock is less than 1pS and all digital inputs are up-sampled to 211Khz.

Upgrade Note: If you are sending in your Avocet for the Quantum DAC upgrade, you will receive an optical input that replaces the original dual wire AES input. Cool, now you have AES, S/PDIF, and Optical.

The design is utilitarian and solid- sporting a modern industrial build with primary colored buttons and center volume knob. This might sound strange, but it always reminded me of Jacque Tati and his modernist take in films like Playtime (go to 23 sec). Monsieur Hulot would surely get lost in the maze of colored square buttons ;). The Avocet proves smart modern design can improve the future for all…err, yeah that is… for Audio Engineers!

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Talking with David Hill at AES last year revealed his excitement about this new Quantum DAC design. In particular, David felt that the combination of filters being analog and some digital help provide a more realistic impact of sound. His words, if I remember correctly were, “a snare hit now sounds more like the real snare.” Now that I had Mr. Hill’s new Quantum DAC in hand, it was time to test it out.

To listen, I brought the upgraded Avocet down to a studio with Lipinski speakers and amps. There, we also had a previous generation Avocet to listen to and compare. A good hour of warm up was given, and a couple more listening to various digital audio sources from the SADiE DAW. Quantum entanglement aside, we began listening to this latest generation DAC design from Crane Song.

Using some familiar music tracks, we fed the Quantum DAC via AES/EBU, then out to the Lipinski speaker system with amps. It certainly sounded good right off the bat, but only after spending a little time did all the new sonic upgrades become clear. Switching to the previous generation Avocet DAC proved that this new design provided a more robust or dimensional envelopment to sounds. David was right about the snare sound. Even more, the guttural impact of kick drum was solid and more 3D. Instruments achieved a more realistic timbre and acoustic space with this Quantum DAC upgrade. While the previous generation DAC is no slouch, this new design allows a more fleshed out roundness to the instruments in the stereo image. remoteThe user-interface offers simple and functional controls that allow you to smartly and intuitively work. With the precise relay based volume control (with offsets for level matching) and brilliant class A output stage, the 5th generation Quantum DAC furthers audio resolution while maintaining full control of your audio sources. The Crane Song Avocet maintains its place as the hidden gem of my audio experiences. My highest recommendation.

-Happy Listening!

The State of Digital Audio Cables

 

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Audioquest USB cables for digital audio, Coffee in focus

After recently writing about solid core audio cable designs, I began listening to various digital audio cables.  To dig in, I started by examining the transmission from computer to DAC (digital-to-analog converter) via the Audioquest USB cable line. For this listening test I employed the Antelope Audio Zodiac Platinum DAC with 10m Clock – simply connected to amp and speakers (Lipinski, and Green Mountain Audio).

The basis for the Audioquest designs start with solid core copper, then they add silver in varying amounts, a noise dissipation system, and finally a DBS or dielectric bias system.

Starting with a generic USB cable I familiarized myself with the sound. To be fair, I listened to several generic type USB cables…not all are created equal, and yes some sound decent too. After establishing the best sounding generic USB cable, I began exploring the Audioquest designs.

The Pearl, a basic LGC (long grain copper) USB cable was implemented from computer to DAC. Compared to the generic USB cable, the Pearl provided a modest but noticeable step up in clarity to the music files. The Forest, with its mere 0.5% silver over copper was easy to distinguish from the sound of the Pearl USB. A distinct and greater clarity came upon first listen, and continued use proved it more detailed indeed. A layer of background vocals was now more apparent. Moving past the Forest, one encounters the Cinnamon USB. At 1.25% silver over copper, this is still in the range of affordable USB cables (ok, for music lovers). The Cinnamon is yet again, more resolute. Not just more resolute, but better controlled and more balanced than the Forest. Next up, the AQ Carbon USB employs a whopping 5% silver over copper. This is also where Audioquest begins adding a 3 layer noise-dissipation system around the USB cable. If the Cinnamon was better balanced, the Carbon adds a more relaxed presentation – possibly due to less noise riding on the conductors. The Carbon also provided a greater sense of depth.

The last two USB cables in the Audioquest line include a 72v DBS (Dielectric Bias System). First up is the 10% silver over copper Coffee USB cable. After noticing the obvious clarity, balance, and extreme quietness (no background hash), another characteristic to the stereo field becomes apparent. Stereo height and depth information becomes easily distinguished. The arc of sound in the stereo field becomes less congested. Low, Middle, and High frequencies have a specific horizontal plain they reside in. Using the Lipinski Speaker system with subs (in addition to my 2way speakers) made this very obvious.

What comes after 10% silver, well 100% PSS (Perfect Surface Silver) of course. The Diamond USB is the most expensive offering from Audioquest. This USB cable spotlights ultra clear transmission while still being hash-free. Like Coffee USB, the Diamond possesses quiet backgrounds, great dimensionality, and rendering distortion free audio signals. Where it differs in sonic presentation is in the stereo height or arc. Compared to Coffee USB, I found the Diamond to create even greater distinctions between low, middle, and high frequencies. Specifically, center vocals were presented physically higher above the speaker than with the Coffee. While some stereo system might benefit from the Diamond, we found the Coffee USB to have the best overall balance in our systems.

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Audioquest Coffee AES/EBU

To test out the Audioquest AES/EBU cables, I used my trusty Yellowtec PUC2. The PUC2 is a USB to AES converter. This allowed me to listen with basic Canare AES/EBU cables and compare them to the Audioquest designs. Note: I used the same AQ USB cable as AES/EBU cable being tested, for the Canare AES/EBU I used a generic USB cable to connect the PUC2 to computer. Canare AES and the AQ Coffee/Diamond were compared using the Crane Song Avocet (with Quantum DAC update).

Starting with the Canare AES cable, I connected the the AES out of the PUC2 to my Crane Song Avocet DAC. From the the Crane Song Avocet, I went into Lipinski Sound speakers with amps. Using the same track (Paul Simon, Proof), I began listening. After familiarizing myself with the sound, I quickly swapped the Canare AES/EBU for the AQ Coffee AES/EBU.

I was stunned by the differences, and so was my colleague (a seasoned mastering engineer). Just as I heard when using the Coffee USB, the AES cable provided a clarity and distinction to the many layered tracks of this Paul Simon mix. Bass was tighter, better defined, more robust. Middle and high frequencies also benefited from greater clarity while still being balanced yet distinct. The stereo arc allowed height information to be easily perceived and not exaggerated. Swapping back the Canare AES cable made it apparent that the sound was now congested, or squeezed sounding.

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Audioquest Diamond AES/EBU

When replacing the Coffee AES/EBU for the 100% Perfect Surface Silver Diamond, the height information became even more distinct. That arc (in the stereo field) I spoke of earlier was even more pronounced than on the Coffee AES/EBU. Extreme clarity and low background noise was obvious, but Paul Simon’s voice appears to be physically higher in the center image. When testing this AES/EBU cable in my home system I noticed the same phenomena.

The Audioquest USB and AES/EBU cables offered a clear improvement that was easily heard. While the Carbon and Coffee were my favorite designs, even the entry level USB cables from AQ provided a clear balanced presentation without any harshness.

-Happy Listening!

 

High Definition Vinyl Technology

 

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HD Vinyl- involves 3d-Based topographical mapping & laser inscription technology

Digital Music News reports that a new technology has been developed to produce higher fidelity sound on vinyl records. Confirmed through a European patent filing, this new technology uses a combination of 3D based topographical mapping and laser inscription technology. Read the full press release here.

Benchmark’s AHB2 Stereo Amplifier

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Achieving the full performance/responsiveness out of my speakers has motivated me to examine various amplifiers designs lately. In this quest to squeeze the last sound molecules from my speaker drivers, I have been comparing class A, Class A/B, Class D, and now this hybrid Class H and AB design from Benchmark and THX.

Delivering clean power with an exceptionally low noise floor are the key ingredients to Benchmark’s new Amplifier. The AHB2 is a 2 channel audio amplifier with 100 watts of power into 8 ohms, and 190 into 4 ohms(bridged mono mode 380 watts/8ohms). This super quiet amplifier topology allows for a signal-to-noise ration of 130dB unweighted. The distortion is also quite low, at 0.00011% THD in stereo mode.

With a clean and tidy footprint, The front panel allows access to 1 power button, and several LEDs that indicate proper operation. Benchmark built into the AHB2- a power supply fault protection to monitor voltage, current, and temperature. If issues arise, the fault circuit mutes both channels to protect the amplifier and speakers. The clip lights will illuminate when occasional clipping is present (something that never happened for me), and the fault protection kicks in when severe overdrive occurs- to protect speakers.

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On the business end of things, connectivity is straight forward. Other than the addition of Speakon connectors, the Balanced XLR inputs and speaker terminals are standard. One dip switch on the right controls mono or stereo operation, while the 3 position switch on the left controls input sensitivity – a welcome feature. Matching the input sensitivity allowed me to optimize the Gain control between the Crane Song Avocet and the AHB2.

Technically speaking, the AHB2’s Vanishingly low noise floor can be compared to the dynamic capabilities of a 22-bit digital system. Most current professional and audiophile DACS can also achieve very low noise floors – a match made in audiophile heaven.

I used the Crane song Avocet and several other DACs to feed Balanced stereo program material to the AHB2. For speakers I used my Green Mountain Eos HX 2-way speakers. All cabling was balanced solid core copper.

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The tidy AHB2 Amp runs cool

I gave the Benchmark amplifier some time to warm-up and have had it in my system for several weeks. My initial reaction was in the form of a grin, as I heard my music amplified in a clear and coherent manner. The extremely low noise floor became revealed as orchestras truly faded to the acoustic space and black was truly black – no residual noise whatsoever from speaker drivers. Even more obvious was a clarity to the amplification. This amplifier runs like a high-performance sports car. I was amazed at the AHB2’s ability to keep up with dense music mixes and never sound congested or lacking. In fact, this tidy beast produced some of the tightest low end I’ve ever heard in my 2 way speakers. The midrange was articulate and clear with an obvious clarity that bested my current class A/B amplifier. Extending to the high frequencies were equally clear and distortion free, no hype here- just honest clean reproduction.

Listening to Beck’s “Morning Phase” (24/96) was ear opening and lovely on the AHB2. The track “Morning” enters with  acoustic guitar strumming and stereo vocals, and leads into lovely strings with reverberant stereo space all around. Even with this wash of sounds, the hit of the Floor tom, or the crisp full fleshed out sound of the snare was colorless and clearly projected.

The Royal Liverpool Philharmonic’s performing Hovhaness’ Mysterious Mountains (Telarc 16/44.1) was sublime. Mount St. Helens Andante, Grazioso unfolds gracefully and with tip top double bass walking the piece along. The bass holds true and rings out even as the full strings come into glide the momentum along. The expansiveness of this orchestral recording is deep and wide with excellent localization. Acoustically, the AHB2 performs so cleanly and quietly that it resolves the hall and space between musicians distinctly- something professional engineers and audiophiles can equally appreciate.

The Benchmark amplifier allowed for dense music mixes to be fully appreciated. Micro-dynamic detail was never lost or distorted, even as complex passages competed. Orchestral and Popular music mixes equally excelled on the AHB2 with authority, control, and balanced sonic presentation. If you are looking for an amplifier that can reveal your source material and DAC without flinching, then the AHB2 is a top choice.

Happy Listening,

HiFiQC

Photography: Vahan Baladouni

 

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Frank reveals the Benchmark Media AHB2 Audio Amplifier:

Read the full review here

For the past couple weeks I’ve been auditioning the Benchmark Media AHB2 amplifier, and will be featuring a full review soon. Inside the tidy footprint and magnetically shielded casework of the AHB2 are a host of unique advances in audio amplifier design….and boy is it quiet!

Stay Tuned -HiFiQC

Crane Song Debuts Avocet IIA with Quantum DAC at AES 139

Crane Song Avocet IIA with Quantum DAC

Crane Song Avocet IIA with Quantum DAC

While I was making my way through the exhibition floor at AES139, I ran into owner/designer, David Hill of Crane Song Electronics. I have been a user and big fan of Mr. Hill’s designs and today I was in for a treat. The Avocet monitor controller had undergone some upgrades and David Hill was excited to tell me about it. I was first treated to a comparison of the upgraded DAC, and then we shot a short video describing the various updates to the Avocet IIA Quantum DAC.

My first video for HiFIQC

Solid Core Copper vs. Stranded Copper Audio Cables

Solid Core Copper Cable by Evidence Audio

Solid Core Copper Cable by Evidence Audio

The way audio cables are constructed can certainly make a difference to their sonic characteristics. Over the past several years I have been comparing the sound transmission characteristics of different copper conductors. In addition to the conductors, different geometries, dielectric material, and shielding can make a cable sound different. While these can influence the sound, I feel the primary sonic impressions I have been hearing have to do with the interaction of conductors carrying an audio signal. Using both stranded copper and solid core copper audio cables in a variety of setups has allowed me to hear the differences.

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Stranded Copper Wire photo from Jimmy’s Junkyard

We use stranded copper wire in pro audio applications for a  couple of reasons. One main reason is that flexibility is important when dressing microphone and instrument cables. A stranded cable will be much more robust when repeatedly coiled up and unwound. The many strands of thin copper can withstand more bending than a single solid core copper wire. It’s the transmission characteristics that differ. With all those strands the signal tends to jump from strand to strand, and with a single solid core conductor this cannot occur. The sound characteristic of stranded copper vs solid core may seem minute, but any well trained ears should hear the difference. This example from Evidence Audio compares stranded monster cable vs. their solid core cable using a bass guitar.

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Gibson SG with Evidence Solid Core Lyric HG

Having heard the difference between stranded copper and solid core copper in my pro audio monitoring chain, I was curious to examine the sonic difference with electric instruments. For this, I employed the help of a 1973 Gibson SG and a Dr. Z MAZ 18 (non-reverb version) tube amplifier. After playing for some 30 minutes with a Mogami stranded copper cable, I switched to the Evidence Lyric HG. My first impression was that a haze had been lifted from my guitar sound. As I continued to dig into this new-found sonic experience I also noticed that my SG had become more responsive to my playing. Rather, a dynamic contrast now clearly existed and I was in control of the shading.

Switching back to the stranded copper cable immediately sounded blurred. The word that comes to mind is distortion, or disruption of the original signal. The guitar sound was now less pure. I want to avoid using words like darker or brighter, because what I was hearing had to do with the signal integrity. Yes, the stranded cable might sound darker, but I feel blur is a better word. On the other hand, the solid core guitar cable was clear and did not adding anything to the original signal.

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Analog Synthesizer with Evidence Audio Solid Core Cable

To further examine the sonic benefits of solid core copper cable, I pulled out an analog synthesizer. The Elektron Analog Four is capable of producing a variety of sounds with its analog oscillators, filters, and beyond. For this test I chose to use a simple sawtooth waveform and  a sub oscillator from this analog synthesizer. After using the stranded Mogami cable for the initial listening, I swapped it out for the Evidence Lyric HG balanced cable. The clarity of the sawtooth wave when transmitted over solid core wire was evident, but when I began adding sub harmonic oscillators, the difference truly stood out. Sonic integrity comes to mind. While adding sub harmonic oscillators to the original sawtooth waveform I was very pleased to experience a more (obvious and clear) layered sound.

These solid core cables from Evidence audio truly allowed me to hear the various harmonic additives I was creating on this synth. Moving back to the stranded copper showed me that the full tonal characteristic of the synth was lessened to a degree. Adding in the sub harmonic oscillator with a stranded cable is easy to hear, but the delineation of harmonic content (clarity) was not as good as with the Evidence Audio cable.

Happy Listening!

The Focal Spirit Professional – Accurate/Natural Sounding Closed Back Headphones

 

The Textured Finish of the Spirit Pro

The Textured Finish of the Spirit Pro

The bottom line for most field recording engineers goes something like this: “what I hear, better be what I get on this recording.” While great microphones are responsible for the actual pick-up of sound, an accurate pair of headphones is the key ingredient to making sound judgements. Whether one intends to record dialogue or stereophonic information, truly hearing the microphone(s) is essential for quality recording. Strapping headphones over your ears is always a compromise when compared to listening over speakers/monitors, but in some environments it is just unavoidable.

Enter the Spirit Professional headphones from Focal:

Over the past several years Focal has introduced several headphones, and their latest offering is aimed at the professional audio market. These cans sport a textured black spackle-paint for durability and memory foam headband/earpads. The speaker drivers are made of a mylar/titanium material which claims to have a balance of rigidity/lightness and high damping properties. All this engineering is to ensure the transducers are capable of delivering dynamic natural sound reproduction.

Fit and Comfort:

The shape of the ear pads are circumaural, that is, they are designed to rest around the ear. After using these headphones for weeks in the field, I have to say they offer excellent passive noise isolation, but the ear pads tend to press on the outer edges of my ear more than say the Sennheiser HD-600 circumaural design. While the foam used is comfortable , I find the pressure coupled with the slightly smaller pads to limit my use to 45 min- before removing them for relief. This is not a complete deal breaker, as I don’t wear headphone all day and often remove them when between recording takes. Still, if maximum long term comfort are your goals in a sealed headphone, you may want to investigate other options.

Listening:

My first test for these headphones involved using direction microphones. Both Schoeps cardiod and shotgun mics were employed to record a variety of male and female voices in various acoustic environments. Schoeps are know for having an even frequency response across the polar patern. Even so, I was impressed with the Focal Spirit Pro’s ability to translate the slightest of off-axis positions to the human voice being picked up. Yes, the Schoeps have a wider sweet spot than most directional condensers, but getting the best position was aided with use of the Focal headphones.

The Spirit Pro’s also held up well when making stereo microphone adjustments. When I found myself without speakers to monitor, the Focal’s presented enough front-to-back depth and imaging to make appropriate balance adjustments. I certainly still prefer to do this type of balancing with speakers, but to my surprise the Focal’s closed-back design permitted me to hear into a recording, rather than just being a completely flat soundstage, or blob of sound. These headphones also have an excellent frequency response. Even though they are strapped close to your ear, I could hear problematic rumble from infrasound and wind more easily than my previous Sony 7509/7510. With Sound effect recording, these cans reproduces all the nuance that I so often find glossed over with professional headphones.

Focal Spirit Professional-circumaural, memory foam, detachable cable

Focal Spirit Professional-circumaural, memory foam, detachable cable

Listening to Music: 

For the audiophile or music lover that insists on headphone listening, the Spirit Pro’s tell the truth. That is, flaws in recordings stick out, and well engineered recordings sound gorgeous. The comfort of these headphones will prevent most users from wearing them for long periods, and the precise nature of the Focal’s means that most details are more upfront than cans like the Sennheiser HD-600( I know the HD-600 is an open back design, but still a reference from my orchestral recording). As an engineer I don’t mind that the Spirit Pro’s aren’t as gentle or sexy as the HD-600’s. Rather, I’ll take sheer resolution over a laid back sound.

Aside from my own recordings, I chose some familiar recordings such as Buena Vista Social Club, Karajan Beethoven. For Modern recordings I used tracks from Beach House and Stereolab. Listening to orchestral recordings made in halls with lovely acoustics sounded fantastic on the Focal Spirit Pro. Where as modern pop recordings could sometimes benefit from the gentler presentation of the HD-600’s.  While engineering decisions could be made with the Sennheisers, I felt the Focals’s allowed me to more readily hear any issues going on with a recording. For pure listening pleasure, I might look elsewhere as the Focals are more a tool than a pure pleasure listening headphone.

Included Cables; coiled, straight w/ smartphone mic, 1/4 screw on adapter

Included Cables; coiled, straight w/ smartphone mic, 1/4 screw on adapter

If you are looking for a headphone that will help you make decisions about mic placement and EQ adjustments, then the Focal Spirit Pro ranks high in my book. In addition to being solid and neutral in sound, they also do a superb job with passive noise isolation. On the other hand if you are more interested in long term comfort I would look at other models. Even though I have been disappointed with headphones for making sonic decisions in the past, I can clearly say the Spirit Pro gives me an assured even response that allow me to work effectively and efficiently.

 

Associated Equipment:

Sound Devices 744t

Great River MP-2NV

Benchmark Media ADC1

Crane Song Avocet

Meridian Explorer

 

 

Sesame Seeds or Desert Sand Windstorm?

Sesame Seeds in Glass Jar

Sesame Seeds in Glass Jar

Here is one method that I can use to evoke the sound of wind, or fine grains of sand being swept around in a storm. By pouring a large jar of sesame seeds into another glass jar, I can create a “desert wind storm” sound effect. This is just a taste of what can be done:

Inspiration for Sound Design: Guadalupe Sand Dunes

Inspiration for Sound Design: Guadalupe Sand Dunes

As always, I can provide higher quality versions, or work with you to customize specific sound effects.