DSPconfig 26.9.0 and Firmware v1.8
DSPconfig 26.9.0 is now available, together with firmware v1.8 for the DSP-8C.
Charting of filters has been overhauled, now offering the ability to display a channel's full signal chain with all DSP applied to it. The other major change is that we have changed our DSPconfig version numbering to calendar-based. Firmware v1.8 for the DSP-8C improves Windows WinUSB driver behaviour and the handling of S/PDIF channel status bits.
The full changelog lists everything in this release, and selected highlights are as follows.
Charting improvements
It's been a longstanding wish to display a given channel's full signal chain with all DSP applied, from input through to output. In this version, we've added an "Options" menu to the charts, with a "Signal chain" setting which toggles that view on and off.
The frequency axis now extends to Nyquist (half of the profile's configured sampling rate) and allows you to zoom and pan. Once zoomed, a "home" icon appears in the chart toolbar which will reset your view.
The magnitude axis now has three pre-configured ranges (-12 to +6dB, -24 to +12dB and -50 to +20dB) so that you can either view a narrower magnitude range in more detail, or a broader overview of the filter(s).
We are continuing to develop the charts and welcome any feedback from users. Our goal is to find the balance between something that is intuitive to use whilst providing the flexibility to handle more complex filter configurations.
A new version numbering scheme
Historically, we've always used 1.x version numbering for both DSPconfig and bundled firmware. However, we found that it was getting confusing to keep track of which version number referred to what, and this will only get more confusing when we release the DSP-4C. As such, we've switched DSPconfig's version numbering scheme to be based on release date - the format is YY.M.N (2-digit year, unpadded month and an incrementing number starting each month from zero to track more than one release within a single month).
Today's release is therefore 26.9.0. This scheme is better suited for applications and gives you an idea straight away for whether or not you are on a recent release. Firmware keeps its 1.x version numbering, and the bundled DSP-8C firmware is v1.8. When the DSP-4C is released, it will start at v1.0.
Windows USB fixes
Up to this point, on Windows, the DSP has used Microsoft OS 1.0 descriptors to ask Windows to install its WinUSB driver, which is what allows Windows to recognise the DSP without requiring any additional driver installation. One user reported that their DSP stopped being recognised by DSPconfig, and it turned out that Windows had installed the driver without one of the settings DSPconfig needs to find the device. Uninstalling the misconfigured driver manually allowed the DSP to be detected again without further issue.
Firmware v1.8 uses the newer Microsoft OS 2.0 descriptors instead, with which the driver installs completely.
There are also a handful of minor fixes that make the USB connection more resilient.
Installing and updating DSPconfig
On Windows, DSPconfig now comes as an installer rather than a standalone executable. It adds a Start Menu entry and an uninstaller, installs for the current user without asking for administrator rights, and installs over a previous version in place. If you have an old DSPconfig.exe sitting in your Downloads folder, you can delete it; your settings will automatically be carried over.
On macOS and Windows, 'Help > Check for Updates...' can now download and install an update itself and restart DSPconfig, rather than just linking to the website.
On Linux, the .deb now adds CoLinear Acoustics' APT repository, so upgrades arrive through apt upgrade or your desktop's update notifier. We also now distribute an .rpm for Fedora and the Red Hat family, which does the same through dnf upgrade.
In all of the above cases, you will still need to manually download and install 26.9.0 in the first instance, and the update pathways described will apply thereafter.
Other changes
When drawing the phase response of an FIR filter, the chart had previously assumed the filter's delay sat in the middle of its taps, which is true of a linear phase filter but not of a minimum phase one, so a minimum phase correction (from rePhase, for example) was drawn with its phase wrapping hundreds of times across the audio band. The delay is now measured directly from the filter's response and all FIR filter phase responses now draw correctly. Only the chart was affected; the filter itself was always applied correctly in the actual DSP pipeline.
EQ filters can now be placed up to 40kHz, up from 22kHz. The old limit was inherited from REW, and it left no way to correct the breakup resonance of a hard dome tweeter, which sits around 25 to 30kHz for aluminium or titanium and nearer 40kHz for beryllium. Most users don't need to worry about correcting frequencies that high up (beyond the upper limit of human hearing), but it doesn't cost us anything to raise the old limit and gives advanced users more flexibility.
Download now available
Firmware v1.8 is delivered as an in-app update, from the 'Device > Firmware...' menu in this version of DSPconfig.
DSPconfig itself is a free download for Windows, macOS and Linux, and offers a demo mode for exploring its features without requiring the purchase of a DSP.
Michael