ACXO

Acoustic Correction and Crossover   for a digital audio processing system running under Windows
 

 

 

Revision 1.3                                           

Last updated September 4th, 2004

Patrick Cazeles

 

ACXO Download (~4.1MB .zip)

                     

ACXO documentation (~1.1MB .pdf)

 

This project started sometimes in May 2003 with the objective to replace the CD player by a PC and integrate acoustic correction & digital crossover.

 

The current version main features are:

 

 Ø        can run on a second-hand computer (high speed CPU not required)

 Ø        cover as much as possible with the computer (i.e. no electronic crossover)

 Ø        no CD player (audio data copied on hard disk)

 Ø        digital room correction support

 Ø        bi- or tri- amplification support (Asio mode)

 

This version 1.3 main addition is a DRC Graphical User Interface. It is now possible to connect a microphone, push a couple of buttons and listen to the DRC correction after a few minutes.

 

This software version has been used with the following hardware:

1.       Mini ITX EPIA MII 12000,  256MB RAM, Fujitsu 80GB HDD, Windows XP Pro (completely fanless)

2.       250GB external hard disk with firewire interface

3.       Lynx AES16 sound card

4.       Apogee Big Ben master digital clock

5.       4 x Tact digital amps (bass/mid-low/medium/treble)

6.       YL compression drivers with horns (mid-low/medium/treble)

7.       Altec 515 bass drivers with Onken cabinets

 

Note: during playback, there is neither screen nor keyboard connected to the EPIA and the remote control is done by wireless PDA.

  

 

Acknowledgements

This package is the integration of existing free libraries or modules. This approach dramatically reduced the development time and made it possible to add functionalities which would not have been practical otherwise. I want to specially thank the following teams or individuals for making their software freely available:

 

·          Read/write audio file library: LibSndFile V1.0.3 at http://www.zip.com.au/~erikd/libsndfile/

·          Upsampler: autools-1.2.0 rateconv at http://www.tnt.uni-hannover.de/~purnhage/software/autools/

·          Digital crossover: Tony Fisher Mkfilter at http://www-users.cs.york.ac.uk/~fisher/mkfilter/

·          Convolver: Gian-Carlo Pascutto at http://sjeng.org

·          Logsweep: Angelo Farina at http://www.ramset.com/aurora/

·          Audio IO library: PortAudio V18 at http://www.portaudio.com/

·          ASIO drivers SDK: Steinberg at http://www.steinberg.net/en/support/3rdparty/asio_sdk/index.php?sid=0

 

Finally, I want to extend my most grateful thanks to Denis Sbragion for his DRC module at http://freshmeat.net/projects/drc/?topic_id=114. DRC is the most complex and important part of the whole package.

 

This is free unsupported software for private purpose only and it cannot be sold or be part of a commercial product. The software is provided "as is", without warranty of any kind and the author is not liable for any claims or damages and its consequences that might occur from the use of this software.