FIR Filtering – Firmware releases across the entire 4 Series platform…

Posted by | January 17, 2013 | | 13 Comments

As of this afternoon, all 4 Series firmware versions have been bumped up to 2.20, giving them all newer units FIR filtering capabilities, as well as enhanced remote control capabilities (more on that in the following post).  I have written at some length about how we have implemented FIR filtering (careful here – it’s FIR filtering NOT FIR filters! 🙂 ).

Have a read through these associated posts to find out how it works and what it can do for you and your system –
Part 1 (Background)
Part 2 (Implementation)

Remember these posts were written late last year before  we had fully checked out the possibility of implementing this in all 4 Series units so they refer to the DP448 only, so the serial number references about DSP platform are specific to 448s only.

Also remember that this upgrade will only work in 4 Series which have the newer DSP platform (to date, units less than two years old, roughly speaking).  You can check what platform your unit has in a couple of ways:

If the unit is running the latest firmware (currently V2.20) then the display will show

 += AudioCore DP448 =+
 === Software V2.20 ===

if the compatible DSP platform is fitted or

== AudioCore DP448 ==
== Software V2.20 ===

if the incompatible older DSP platform is fitted.  The “+” at each end of the top line instead of an “=” is the signifier of the newer DSP.

You can also check in the System Status through the System Sub-Menu – one of the scrolling messages will either show

System Status
= DSP TYPE=2 Number=1 =

if the compatible DSP platform is fitted or

System Status
= DSP TYPE=1 Number=2 =

if the incompatible older DSP platform is fitted.

You can still load this firmware into older units, and gain the advantage of the extra simple remote control commands, but the FIR filtering support won’t exist.  As ever, we always recommend you update your units’ firmware inline with a new release of AudioCore to ensure they play together happily 🙂


  • Gabor Bacskay says:

    Is there any chance to have FIR filter on the Martin Audio DX2 (OEM448) processor with an update?

    • admin says:

      Hi there Gabor.
      Good question – the potential is there to implement this, but it’s really something you’d need to ask Martin themselves,
      as it would obviously have to come though them. What application were you considering for the FIR filtering?
      Technical Brand Manager XTA/MC2

    • admin says:

      Hi there – currently as you know the DX2 does not support FIR filtering – we would recommend you experimenting with a DP448 and seeing if you can achieve the results you require and then contact Martin about it – it is theoretically possible to support FIR filtering, but of course we don’t want to stop selling DP4 Series as a result!
      Waring [Hayes]
      Technical Brand Manager

  • Pacera says:

    Hi, why the DP548 wich is more recent, is not compatible with this new Firmware ?

    • admin says:

      Hi there – the short answer is that the extra processing that is available to support the FIR filtering blocks on the 4 Series is used to add the multiband dynamic EQ across each input and the compressors on each output.
      Also, the use of FIR filtering, especially in areas of phase distortion correction, would not really work with dynamically applied input EQ.
      If you want to use standard 4 Series presets with the DP548, the presets can be ported across, but the FIR sections will be bypassed.
      Hope this answers your question.
      Waring [Hayes]
      XTA Technical Brand Manager

  • Tamas Borsodi says:

    Hi Admins!
    I need a little help: In my DX2(oem 448) run firmware V1.0.
    What a correct latest update for me ( maybe 2.3?)?

    Best regards : Tamas Borsodi

  • Anton says:

    I have a martin DX2 oem448 with firmware version 0.01A, where i can get a update ?

    • Waring Hayes says:

      Hi there – sorry for the late reply – we’ve been moving the website to a new server and so some messages have been neglected during this time, but it’s all working again now!
      Martin Audio should be able to provide you with the latest firmware and presets release – please send an email to and Nigel should be able to get this for you.

      Best regards,

      Waring Hayes

  • chordman says:

    How to Change FIR MODE?

    • Waring Hayes says:

      Hello – thanks for contacting us.
      You do not need to select an FIR mode on the 4 Series – presets are designed to incorporate FIR filtering and if you recall one with this enabled, it will be working automatically.

      You can see if the current preset is running an FIR filter on any output by selecting the GAIN screen for that output – if there is an “F” beside the gain value then an FIR filter is active on the at particular channel. Note that only output channels can support FIR filters and it is quite possible that not all channels in any preset will have FIR filters running.

      Please read the two TechBlog posts about FIR Filtering and its implementation on 4 Series here:

      Best regards,


  • Mohamed says:

    I have a question..
    What is the difference between xta and martin processor 8 channel .. Is it the same device?

    • Waring Hayes says:

      Hi Mohamed,

      The Martin Audio DX2 is based on the DP448, but has some features restricted – no input graphic EQs, some output filter types missing (bandpass, notch, elliptical, all pass, phase), and they cannot work with FIR filters. Both the DP448 and the DX2 are supported in AudioCore.

      You cannot change a DX2 into a DP448 with a firmware change.



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