From 47855d91d4d3cf05a8926a45a8b2b17f70f48d51 Mon Sep 17 00:00:00 2001 From: Bdale Garbee Date: Mon, 22 Dec 2014 14:44:29 -0700 Subject: [PATCH] meh --- electronics/audio/wholehouse/index.mdwn | 44 ++++++++++++++++++++----- 1 file changed, 36 insertions(+), 8 deletions(-) diff --git a/electronics/audio/wholehouse/index.mdwn b/electronics/audio/wholehouse/index.mdwn index e568014..0350883 100644 --- a/electronics/audio/wholehouse/index.mdwn +++ b/electronics/audio/wholehouse/index.mdwn @@ -1,13 +1,41 @@ # Whole House Audio System We're designing a completely open hardware and open source solution for -whole-house audio distribution. - -The key hardware component is a board containing a USB audio interface -and stereo 50 watt class-D audio amplifier. A set of these boards, one per -"zone", get wired to speakers in the various rooms. A Linux system runs -software that controls audio stream sources, maps them to the various zones, -and volume controls the zones .. all controllable from a web browser or -Android application. +whole-house audio distribution. The intent is sufficient audio quality +to support a pleasing background music experience around the house... not +to be an audiophile-level system. + +## Motivation + +The system proposed by our builder was hideously proprietary, and apparently +violated the GPL. Just couldn't do it... + +## System Design + +Our builder had a sub-contractor install ceiling-mounted speakers in each +of 9 zones in our house. Each zone has a local impedance-balancing volume +control to allow for local / emergency "turn it down" capability. There's +a wire bundle from each zone to the central mechanical room consisting of +4 conductors for the stereo audio, and 4 twisted pairs (ala CAT-6) we don't +intend to use immediately. + +The new hardware component Bdale designed is a board containing a USB audio +interface and stereo class-D audio amplifier. The USB audio DAC part was +designed by Burr-Brown and is now a Texas Instruments part. The class D +amplifier is also a TI part, available in 15, 30, or 50 watts per +channel. While the PCB layout can handle any of these parts, the 50 watt +per channel part needs additional heat-sinking and we just don't need that +much power. So we built the system using the 30 watt per channel parts. The +circuit board is 2.75 x 1.25 inches and less than an inch thick fully +populated. + +A set of these boards, one per +"zone", each attach to the speaker wires, a DC power supply, and a USB hub +that is attached to a Debian system in the mech room. + +The Debian (Linux) +system runs software that controls audio stream sources, maps them to the +various zones, and volume controls the zones .. all controllable from a web +browser or Android application. More details will be posted soon! -- 2.30.2