Audioquest Mackenzie and Earth interconnects

Audio cables are a curious thing, especially for those that listen closely and hear differences. Materials matter, and more importantly how these materials interact and affect the quality of signal propagation is measurable. I am certainly in the camp of hearing the effects of conductor type, dielectric materials, and various shielding methods. Once the signal leaves your source, preamp, or amp, the cable type can have audible signatures that once heard, are hard to ignore. The more resolving one’s audio system is, the more these differences can stand out.

Audioquest Mackenzie interconnects

Having already listened to solid core digital cables from Audioquest, I was now interested in hearing the analog interconnects also constructed with these similar conductors. The 2 that rose to the top of my listening sessions were the Audioquest  Mackenzie and Earth interconnects. To explore the sound these cables presented to an audio system, I was fortunate to not only use a home stereo setup (Benchmark AHB2, Crane Song Avocet, Clearaudio Concept, Moon LP 5.3), but also a professional mastering rig within an acoustically optimized room in Hollywood.

Starting at the mastering facility, we used Lipinski monitors with two time-aligned JL subs. The source for our listening sessions came from the SADIE digital audio workstation. Clocking for the system was provided by a rubidium oscillator distributed to all digital gear used for playback and recording.

While we had an entire loom of Audioquest Mackenzie to interconnect all the gear in the mastering facility, this was not the case with the Earth cables. With this in mind, we felt a good starting point would be to compare the standard stranded cables often used to interconnect the studio (Mogami) with the Mackenzie.

In a mastering studio we often use analog outboard gear (EQs, compressors, etc) for processing. This requires that the digital audio file is played back via a DAW, converted to analog, processed through the outboard gear, then converted back to digital and captured in the digital audio workstation. This process allowed us to record the same music with both the Mogami cable, and the Audioquest cable in use. After the recording through each set of cables, we were able to playback the two audio files and A/B the results in real-time.

The two stereo audio files (time-aligned) were assigned to their own tracks in the DAW, allowing us to easily switch between them and hear the differences. Starting with the Mogami, the soundstage was smaller, and their was a graininess to the sound. Switching to the audio captured through the Audioquest Mackenzie immediately opened the soundstage width and provided a clarity that was easily heard. Myself and several engineers agreed that the Audioquest cables presented a grain-free clarity that was not available with the stranded copper design (Mogami).

Audioquest Earth interconnects

While we didn’t have enough of the Earth cables to do the same listening experiment in the mastering room, we did have a pair to audition. So, I decided to check these out in my home stereo system. My good friend came over and helped as we switched back and forth between the Mackenzie and the Earth interconnects.

The sound of the  Mackenzie was distortion-free; a stable wide sound-stage, clarity from top to bottom, and excellent stereo depth/height information. Replacing the Mackenzie with the Earth demonstrated further details without being upfront or hard in any way. In fact, the bass was noticeably weighty, carrying the fundamental note with more precision and a deeper impact. Mid-range and high frequency extension proved to be a bit more open and relaxed compared to the Mackenzie.

Digging into the factors of signal transfer will get you started on a path of materials science. Dielectrics (material insulating or surrounding a conductor) can have dramatic affect on the overall sound/energy of an audio signal. I should note that the Earth interconnects are a physically bigger cable. They use FEP air tubes which I think reduces the dielectric absorption of energy in the cable. More specifically, two things are at play here; the air, and the FEP (Fluoro-Polymer). These FEP air tubes provide less contact between the conductor and wall, and the FEP itself provides the lowest energy absorption in an extrudable insulation. These factors may account for some of the sonic differences we heard.

On the other hand, the Mackenzie uses a hard cell foam insulation material to surround the conductors. This foam is then nitrogen injected, a process that creates air between the surrounding material and conductor. The enhanced hard cell foam also allows the conductors to maintain a uniform impedance.

From my experience, outside of conductor type, the most salient sonic inhibitor has been found in dielectric material. But one must be open minded, as a culmination of materials create the sound of Audioquest cables. Further details on their construction can be found at the Audioquest website.

After spending several months with the Audioquest cables I can assuredly contest an enhancement to both professional and audiophile systems. The Mackenzie is my top pick for what audiophiles might consider an affordable top performer. The Earth furthered the sonic traits of the Mackenzie, coaxing out better bass extension and a more dimensional stereo soundstage.

Highly Recommended

Happy Listening!

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.

Crane Song Avocet with Quantum DAC

QuantumDAC

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!

AvocetIIA

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!

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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FrankAHB2

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

139th International AES Convention

Audio Engineering Society's 139th Convention

                                             

Professional audio users from around the world will descend on New York’s Jacob Javits Center next week. The 139th Audio Engineering Society convention will surely be a treat for the ears and eyes. I will be doing the ground work, covering new developments and product releases. Microphones, amplifiers, digital converters, EQ, compression….Keep it tuned to Hi-Fidelity Quality Control for all the latest AES news, from the floor.