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    by Published on 10-15-2014 11:13 AM
    1. Categories:
    2. Network Audio
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    Over the last couple months I've talked to several manufacturers who expressed great frustration over end user network problems. In no way was this a blame game placing blame on the end user, rather just an expression of frustration that each manufacturer was incorrectly blamed for a dysfunctional product. In addition, some frustration was also expressed toward audio dealers who refuse to learn computer networking basics or enough about networking to support the products being sold. Given the level of frustration by manufacturers and end users I think it's a good idea to publish a little refresher on networking for computer audio and provide the CA Community a glimpse into my network as an example of a network that is rock solid and (almost) guarantees flawless performance. I've never had an issue with computer audio that was traced back to a problem with my network. I don't say that to boast, rather to help readers understand that my network and the following examples should suit them well for audio playback.
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    by Published on 12-02-2013 04:31 PM
    1. Categories:
    2. Room Correction
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    In this article, I walk through the steps using Acourate to create a 3-way digital crossover (XO) for tri-amping my speakers. Additionally, using the audio toolbox functions of Acourate, I walk through the steps of time aligning the drivers, linearizing each driver, and performing a final room correction.

    With respect to room correction, I recommend reading, “Acourate Digital Room and Loudspeaker Correction Software Walkthrough” for an introduction to Acourate. The article details the steps of acquiring a calibrated microphone, measuring the system, and designing a baseline room correction to provide the listener with a perceptually flat frequency response at the listening position.

    My goal is to make this guide repeatable so anyone following the same steps should be able to achieve similar results. Using digital XO, time aligning and linearizing the drivers, and correcting the room’s frequency and excess phase response, increases my systems imaging resolution so my speakers *disappear*. ...
    by Published on 08-13-2013 01:01 PM
    1. Categories:
    2. Network Audio
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    Theoretically wireless networks should have been capable of streaming high resolution audio since consumers started adopting 802.11g 54 Mbit/s WiFi back in 2003. Streaming 8 channels (7.1) at 24 bit / 192 kHz requires roughly 37 Mbit/s of bandwidth. Thus, high resolution two channel audio should have been a breeze to sling around one's house ten years ago. Unfortunately real life stood in the way. The actual throughput of wireless network devices has never been close to the theoretical maximum. Issues such as latency, dramatic signal losses due to distance and home construction variables, and the lack of technology to harness the power of wireless signals has made wired Ethernet the only game in town. Some computer audiophiles are fortunate to have wired ethernet networks connecting their music servers to their Network Attached Storage devices (NAS) anywhere in their houses. Others are stuck placing components in less than stellar locations because they can't stretch an unsightly Ethernet cable across the living room. With the release of 802.11ac wireless routers, access points, and adapters many audiophiles previously constrained by the lack of wiring may finally have a solution for smooth streaming. ...
    by Published on 07-17-2013 12:21 PM
    1. Categories:
    2. Software,
    3. Hardware
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    Warning the following article contains some geeky stuff. What follows is a step by step guide to building a tiny 2.4" x 0.82" x 3.54" Linux music server. It's not rocket science and the instructions make the process fairly easy, but the article isn't for everybody. Thanks to CA readers K-man and Richard Dale for additional information and tweaks for setting up the BeagleBone Black so it runs great. Please note there are many ways to setup and configure the BBB. This is just one way using either Mac OS X or Windows. Readers are encouraged to leave comments with additional tips, tricks, and tweaks. I will update this article accordingly. ...
    by Published on 06-20-2013 08:43 AM
    1. Categories:
    2. Room Correction

    In this article, I walk through the steps using Acourate to produce a default or baseline correction that is repeatable. By following the same steps, one should be able to achieve a similar baseline correction. This baseline correction is designed to provide the listener with a perceptually flat frequency response from 20 Hz to 20 kHz. Making the measurement and correction process predictable and repeatable is important to achieving a successful sonic result that one would be happy with.

    Dr. Uli Brueggemann’s Acourate ( approx. $400 USD) is a high end audio toolbox with many functions. The Acourate web site provides a good description of the software solution:

    The sound arriving at the listening position is measured and analyzed. The quality of the direct sound is analyzed preferentially within an adjustable time window. In combination with a target function (adjustable by the user according to listening habits and preferences) a correction filter is calculated. The music signal will be corrected by the filter during playback. Thus an optimized sound will arrive at the listening position.

    Low frequencies cause standing waves in any room, also described as room modes. Some frequencies will be boosted, others will be attenuated. The room correction avoids too loud playback levels by attenuating the corresponding frequency range. Weak levels will be boosted carefully to a higher level.

    Acourate applies a psychoacoustic analysis to ensure correction filters fitting to the human ears.
    Furthermore Acourate corrects timing errors of the room and the speakers by a phase correction. The target is to get as close as possible to an ideal step response, the best possible coherence, and similarity of response between the loudspeakers.
    ...
    by Published on 05-10-2013 02:01 PM
    1. Categories:
    2. Network Audio
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    Intro
    The following guide was designed for audiophiles. The guide describes UPnP based home audio reproduction, provides use pro and cons of UPnP, examples, and recommendations for successful UPnP audio implementations.

    Overview

    Network based audio can be delivered using several different protocols and technologies such as UPnP, DAAP (Apple), and Ravenna among others. UPnP is the most common network audio protocol in use today. It's used in both two channel single room systems and whole house network audio distribution. Ironically UPnP is extremely simple for end users and a bear for product producers. The more one digs into the UPnP protocols the more divergent information with common frustration one finds. This guide will not turn a novice into an expert. I hope it will provide all the information computer audiophiles need to understand and enjoy UPnP based audio playback. ...

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