Enter the world of High Resolution Audio
High-Resolution Audio is More than the Latest Digital Format
1982 brought us the CD and "Perfect Sound Forever". On a top-quality playback system, the CD can sound stunning. Nevertheless, we have come to understand that the 16-bit, 44.1 kHz, CD format is somewhat less than perfect. For this reason, the recording industry is migrating to a variety of high-resolution audio formats. Recordings are now available in 24-bit PCM at sample rates of 96 kHz and 192 kHz. These recordings promise performance that extends well beyond the limitations of the CD, but formats alone are not enough to gain entry to the world of high-resolution audio.
The Myth of High-Resolution Audio
High-Resolution Audio is a myth unless the entire playback system extends beyond the limitations of the CD format. The truth is that the CD format often pushes the limits of very good playback systems. Very few audio systems are capable of rendering the full capabilities of the CD format. Fewer yet are capable of rendering true high-resolution audio performance.
An Audio System is Never Better than its Weakest Link
If a D/A converter, power amplifier, or loudspeaker is limited to CD performance, the entire system will be limited to CD performance. In such a system, the new high-resolution audio formats will fail to deliver any audible improvements.
High-Resolution Audio Components
Benchmark is focused on building some of the highest-quality audio components available. Audio professionals and home audiophiles have come to appreciate the outstanding performance of our products. Benchmark's products will allow you to experience the full capabilities of the new high-resolution recordings while discovering previously overlooked details in your favorite CDs.
Step Beyond the CD and Enter the World of High-Resolution Audio
High-Resolution Playback Begins with the D/A Converter
We live in an analog world. The D/A converter, or "DAC", is the essential bridge between digital storage and analog playback. Today, virtually every audio device has a built-in DAC. CD players, DVD players, computers, HDTVs, cable boxes, and even smartphones, have built-in D/A converters. But there is a problem - these internal D/A converters are rarely capable of delivering high-resolution audio.
Upgrade to an External D/A Converter
The entire audio system in a consumer audio device is normally built for a budget of about $5. These internal converters may boast that they support 24-bits and 192 kHz, but in most cases, they cannot even do justice to the CD format. Internal converters typically provide the equivalent of 14-bit performance. The remaining 10 bits serve marketing purposes.
In contrast, the Benchmark DAC3 external D/A converter delivers the full performance of today's best 24-bit high-resolution recordings.
Digital Connections
Most audio products now have digital outputs. These outputs bypass the internal D/A converters and deliver raw uncorrupted digital data, losslessly preserving all of the details captured in the recording. These raw digital outputs can be connected to an external D/A converter. The resulting performance improvement is often huge.
Volume Control
Any practical audio system will need a volume control. These days, most audio devices use digital volume controls. These controls place significant demands on the quality of a D/A converter. An internal D/A converter that starts with the equivalent of 14-bit performance, may only deliver 12-bit performance at typical volume-control settings. In contrast, the Benchmark DAC3 D/A converter delivers true high-resolution audio performance over a wide range of volume settings. The DAC3 includes the input selection and output buffering functions of a traditional HiFi "preamplifier" and is designed to directly drive power amplifiers.
Amplification
The DAC3 D/A converter can only be fully appreciated when the entire audio chain is capable of similar performance. Audio amplifiers are a weak link in most audio systems. The amplifier often adds significant noise and distortion. It is difficult to cleanly deliver the power and current required by loudspeakers. For this reason, D/A converters have outpaced the development of power amplifiers. Benchmark set out to solve this problem and create an amplifier that matches the performance of the DAC3.
The AHB2 - A New and Different Power Amplifier
The AHB2 uses THX-patented AAA™ technology to virtually eliminate all forms of distortion. We also focused on frequency response, output noise, drive current, damping factor, and reliability. The result is an amplifier that stands head and shoulders above the competition. No amplifier has lower noise or lower distortion than the AHB2. Experience delicate musical details that are usually lost in a veil of noise and distortion.
The SMS1 Loudspeakers - The Final Link in the Chain
Benchmark developed the SMS1 monitors with a focus on achieving low distortion, accurate matching, and a wide frequency range. The quality components and unique crossover design, contribute to the outstanding vocal clarity, natural sound, and excellent musicality of the SMS1 loudspeakers.
A Transparent Audio Path
Benchmark is focused on building products that provide a transparent audio path. We lead the industry with our wide-bandwidth, low-noise, low-distortion designs. Independent measurements show that our products continue to define performance "benchmarks" for the professional audio industry. Many Hi-Fi enthusiasts have joined our loyal base of professional customers. Benchmark products are key components in many of the finest recording studios, but they are also found in many high-end home systems.
Engineered and Manufactured in the USA, Shipped Worldwide!
All Benchmark products are designed and manufactured in the USA. Every product is individually assembled and tested in our state-of-the-art facility in Syracuse, NY. Every unit must meet rigid standards before leaving our plant. Benchmark products are now shipped to virtually every country in the world.
It all Began in 1983
Benchmark began in 1983 as the "Benchmark Sound Company", a small operation working out of a garage in Garland, Texas. Our founder, Allen H. Burdick, began by building very high-performance audio equipment to meet the specialized needs of television broadcast facilities. The company quickly grew, and was incorporated as Benchmark Media Systems, March 5, 1985. Benchmark expanded into additional audio markets, and relocated to Allen's hometown, Syracuse, NY. To this day, all Benchmark products are designed, assembled and tested in our Syracuse facility.
Benchmark - The Measure of Excellence®
We are confident that you will appreciate the audio performance and build-quality of our products. Our goal is to build top-quality products that you will enjoy for years to come. All Benchmark products are robustly engineered to last a lifetime, and are backed by our Extended 5-Year Warranty (USA sales - registration required for warranty extension).
Support - Before and After the Sale
Our Technical Support and Engineering teams will work with you to attain the highest level of performance from whichever Benchmark product you decide to purchase. Feel free to call us at any time with your questions. We are here to provide expert advice. Also, feel free to contact us with suggestions and comments. Feedback from our customers is always appreciated!
Audio Application Notes
Calculating the Performance of an Amplifier/Speaker Combination
Calculating the Performance of an Amplifier/Speaker Combination
In this application note we calculate the maximum output level and noise level produced by an amplifier/loudspeaker combination. Use this example for calculating the performance of your system.
Our Test System - AHB2 Driving PMC IB2S Studio Monitors
At the 141st AES conference we demonstrated two Benchmark AHB2 monoblock power amplifiers driving a pair of 4-Ohm PMC IB2S studio monitors. These monitor are also available the PMC IB2SE hi-fi version.
In bridged mono, the AHB2 can deliver over 518 watts into each of these 4-Ohm speakers. This is a perfect match to PMC's 500 watt recommendation. The AHB2 easily provides the power, the output current, and the damping required by these low-impedance speakers.
"I am very impressed with the clarity and accuracy of these outstanding professional monitors. The Benchmark AHB2 and PMC IB2S are an absolutely killer combination!" - John Siau, VP, Benchmark Media Systems, Inc.
Speaker Sensitivity and Amplifier Power
Speaker Sensitivity
Speaker sensitivity is a measure of how loud a speaker will play at a given input power or at a given input voltage. Sensitivity is normally measured with a 1 watt power input or a 2.83 Vrms voltage input.
There have been many different speaker designs over the years and there are vast differences in speaker sensitivity. The speakers below have sensitivities ranging from about 85 dB to 109 dB.
- What are the power requirements?
- What are the implications for system noise?
- How loud will each play?
- Do they require different amplifiers?
Audio Myths - The Ultimate "Myth Buster" Video - Monty Montgomery, Xiph.Org
Audio Myths - The Ultimate "Myth Buster" Video
Digital Show & Tell, Monty Montgomery, Xiph.org
Monty Montgomery takes us into the lab and uses a series of simple demonstrations to bust some very common myths about digital audio. Test your knowledge of digital audio. This video is fun to watch and easy to understand! Monty takes some difficult concepts and demonstrates them in a clear and simple manner.
Have doubts about Nyquist? Have a fear of stairsteps? Are you worried about ringing? Ever wonder what digital audio does to the timing of transients? This video is for you!
Myth - "Digital audio has stairsteps."
Myth - "Increased bit depths reduce the stairsteps."
Myth - "Analog tape has more resolution than digital audio."
Myth - "Dither masks quantization noise."
Myth - "Signals lower than one LSB cannot be reproduced."
Myth - "Digital filters make square waves and impulses ring."
Myth - "Digital systems cannot resolve timing between samples."
Intersample Overs in CD Recordings
Intersample Overs are a Common Occurrence in CD Recordings
We have frequently used Steely Dan's Gaslighting Abbie from Two Against Nature in our listening tests. This is a spectacular CD recording with lots of dynamics and a low noise floor. Nevertheless, in a little over 5 minutes, this track has 559 intersample overs on the left track and 570 on the right track for a total of 1129. This means that there are about 3.7 intersample overs per second. The highest intersample over measures +0.8 dBFS. The track itself is not clipped, the 44.1 kHz sampling has simply captured peaks that exceed 0 dBFS. The following image shows the track with the intersample overs highlighted in red:
This track can be played cleanly by the Benchmark DAC2 and DAC3 converters. These converters accurately render the intersample peaks that were captured in the recording process. In contrast, conventional converters will clip the peaks. In this track the peaks coincide with hits to the snare drum. Converters that clip these peaks add a false brightness to the snare drum and alter its sound.
