MarcV

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Actually marcV itself is still in an alpha-stage only (too many ideas that have to be collected and coded) and thus not ready for publishing. In the meantime you will find here some DSP utilities that may be useful for you.


maXO Multi-amp Crossover Generator

maXO (multi-amp crossover) may help you to create some crossovers for your system. You can define up to 5-way systems (=4 crossovers). You have to select the crossover frequencies and the desired filter order. maXO will create filters with 65536 taps (either single or double precision). The filter type now is fixed to Butterworth filters. Linkwitz-Riley or Neville-Thiele filter are possible on demand.

Remarks:

  • maXO is a Windows program, however it is fully functional under WINE.
  • Please be a little patient, it is not a really quick program but IMO this is not necessary.
  • The result can directly be used by BruteFIR on a USB memory stick

Download: maXO.zip

marcPM marc Phase Mixer

marcPM lets you easily create a linear phase filter, a minimum phase filter, a maximum phase filter or even mixed phase filters. All you need is a given filter file with 512 - 131072 taps in pcm- or dbl-format. A simple slider (and/or edit field) allows you to control the position of the maximum peak. The input file remains unchanged.

Example for a useful application: you have minimum phase filters for a multi-way system. Thus typically you can adjust the peak of the tweeter filter to the peak of the bass driver by delaying the quicker tweeter. With marcPM you can do the adjustment by a mixed phase filter. The tweeter can start earlier but it will run time aligned with the bass driver.

This idea I found first documented in the dissertation of Swen Müller about 'DSP for Loudspeakers' (only in German, http://sylvester.bth.rwth-aachen.de/dissertationen/1999/2/99_2.pdf). His proposal is based on an algorithm using the group delay. marcPM uses the algorithm published in an AES paper of 1995: 'Interpolation between minimum-phase and linear-phase frequency responses' (http://www.essex.ac.uk/ese/research/audio_lab/malcolmspubdocs/C68%20Phase%20interpolation.pdf)

Warning: Typically linear-phase correction filters created with DRC are not true linear-phase. So marcPM will destroy the phase information of the 'linear-phase' DRC filter. marcPM is for advanced users in such a case. If you use minimum-phase DRC filters, marcPM may be worthful.

Remarks:

  • marcPM is a Windows program.
  • The download package is a quite big (~3.5 MB) RAR-archive (unpacked >10 MB). The reason is that I switched to a IMO very good vector/matrix library (mtxVec). This software library itself uses the INTEL DSP lapack library embedded in mtxVec. So the archive contains two dll-files. You can leave it in the same program directory or copy it to \Windows\system32. All programs that will be added here in the future are based on the same library. You need it to download only once.
  • The deployment of the library is only free in combination with the application program, here marcPM
  • The result can directly be used by BruteFIR on a USB memory stick


Download: Application marcPM.rar --- Vector library MtxVecDLL.rar

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