From DRC

The DRC - Digital Room Correction - Wiki

DRC is the principle of measuring the response of your hifi/home theatre equipment in situ. Then using powerful DSP techniques to generate digital filters which correct for distortions introduced as a result of the room, speaker positioning, speaker imperfections, etc.

Or put simply: use a "computer" to correct the problems caused by placing your speakers in a large echoing box (ie your room), and also to correct the frequency response of your speakers.

The result is greatly increased stereo separation, a much smoother and richer sound and much fuller clearer bass.

What is this site

This site is a "Wiki". This means that anyone can create an account and log in and help add to the site.

The goal is to document all kinds of room correction systems and also provide some "how did it work for me" success stories.

News

• 2008-06-16 DRC 3.0.0 released.
• 2008-05-28 DRC 2.7.0 released.
• 2006-08-05 Room correction for SlimServer/Squeezebox http://inguzaudio.com/ (and User:Hpyle's notes)
• 2006-04-12 How to do room correction with DRC (in Spanish) http://www.che.es/directorio/albums/userpics/10010/DRC.pdf
• 2006-03-20 The foo_dsp_xover multiamplification Foobar2000 plugin now has its dedicated web page at http://xover.sourceforge.net/
• 2005-12-30 Simple Automated IR Measuring Tool "Official" version updated to RtAudio 3.0.3. Should fix most ASIO problems now?
• 2005-12-20 Simple Automated IR Measuring Tool Corrections to rec_imp_jrp for loopback
• 2005-12-15 DRC 2.6.2 released.
• 2005-11-04 DRC 2.6.1 released.
• 2005-08-24 marcV is still developing. For advanced users now another utility beside maXO (crossover generator) has been added: marcPM. You can generate mixed phase filters (including linear and minimum phase filters). marcPM displays the linphase, minphase and mixphase result
• 2005-07-15 An interesting page about Digital Room Correction is now avaliable on the Wikipedia at http://en.wikipedia.org/wiki/Digital_room_correction and has been added also to the DRC links section.
• 2005-06-03 DRC 2.6.0 released.
• 2005-05-14 Simple Automated IR Measuring Tool - Measure the room Impulse Response in one step!
• 2005-05-12 BrutEQ released. A PHP web system to remotely control your Brutefir convolver!
• 2005-05-06 3-way system with digital xovers and DRC, including Octave script for xover generation by Chris Birkinshaw
• 2005-04-29 We have a new webserver which is a lot faster, and I might have some time to write some stuff. Check out our user experiences section below
• 2005-04-12 DRC 2.5.1 is released! Huge improvement in audio in difficult rooms. Can now correct quite close to the theoretical limits of digital correction. Fascinating documentation comes with it!
• 2005-01-25 BruteFIR on a USB memory stick by Uli Brüggemann

All things DRC

• Getting Started
  • What is "Digital Room Correction"
    • Room Correction vs Parametric EQ - How do they differ
    • "Room Correction is Impossible!"
    • Uli Brueggemann on room correction
  • Active systems - or: how to put the crossovers in-front of the amplifiers
  • Passive room treatments - Alternative or complement to DRC?

• How to do it
  1. Setup the System
     • Digital Crossovers
  2. Measuring the impulse response
     • Simple Automated IR Measuring Tool
     • Hardware required to do the measurements
     • Common mistakes
  3. Analysing the impulse response
  4. Compute correction filters
  5. Apply correction filters to the audio
     • Brutefir (Linux)
     • foobar2000 (Windows, stereo)
     • DirectShow/DirectX Convolver filter / Windows Media Player plug-in (Windows, stereo, multichannel)

See also Room EQ Wizard

• Software systems
  • DRC by Denis Sbragion See also: (DRC User Guide), (Building DRC on Linux)
    • ACXO by Patrick Cazeles
  • Audiolense by Bernt Rønningsbakk, brief introduction here.
    • Sound correction and cross over
    • Integrated measurement module
    • User friendly graphical interface
  • Acourate DSP utility collection by Uli Brüggemann
    • delivers both state-of-the-art digital room-correction
    • speaker driver-time-alignment
    • linearization
    • crossover execution in an upgradeable, customizable pc-based solution.
    • (((acourate)))® runs on PCs with Windows or XP and Intel Macs with XP.

• Hardware systems
  • Trinnov Optimizer
  • TacT RCS
  • Lyngdorf TDA2200
  • DEQX
  • Behringer DCX 2496
  • Behringer DEQ 2496
  • SigTech TimeField Acoustic Correction processor
  • Audyssey MultEQ XT

• Success Stories
  • Ed Wildgoose
  • Denis Sbragion
  • Chris Birkinshaw
  • Patrick Cazeles
  • John Elliott
  • Anthony Thompson
  • Neil Mackie
  • Mark Wilcock
  • Arthur Cheng
  • Patrik Johansson
  • GTS
  • Olaf Marzocchi
  • Ronald Verlaan

• Further Info
  • DRC links Selection of links to DSP resources and DRC products