What's new in Digital Room Correction (DRC) 3.2.0
Dec 12, 2011
- A new computation of the RMS value based on a logarithmic frequency weighting of the magnitude response has been introduced. This new method allow for a better handling of the filter magnitude response peak limiting. A bug in the estimation of the band limited RMS value has been also corrected. Some other procedures have been refined in order to provide an improved accuracy. The glsweep and lsconv tools have been reworked to provide correct reference levels thus allowing for SPL calibrated measurements.
New in Digital Room Correction (DRC) 3.1.1 (Aug 19, 2011)
- The licensing of some file has been corrected. Minor corrections and accuracy improvements.
New in Digital Room Correction (DRC) 3.1.0 (Aug 19, 2011)
- The Octave scripts have been reworked to make them compatible with the latest version of Octave and improved to provide some autoscaling features and exports to different image formats. The microphone compensation stage has been moved to the beginning of the correction procedure so that any following stage works using the compensated impulse response as a reference. A new parameter adding a configurable delay to the minimum phase version of the correction filter has been introduced. Many other minor bugs have been fixed.
New in Digital Room Correction (DRC) 3.0.1 (Aug 19, 2011)
- The Octave scripts have been reworked to make them compatible with version 3 of Octave. A new renormalization procedure, providing a reasonable extimation of clipping levels, has been added. Many minor bugs have been fixed.
New in Digital Room Correction (DRC) 3.0.0 (Aug 19, 2011)
- A new method for the computation of an optimized psychoacoustic target response, based on the spectral envelope of the corrected impulse response, has been introduced.
New in Digital Room Correction (DRC) 2.7.0 (Aug 19, 2011)
- A new method for the computation of the excess phase component inverse, based on a simple time reversal, has been introduced. The sample configuration files have been rewritten to take advantage of the new inversion procedure. Sample configuration files for 48 KHz, 88.2 KHz, 96 KHz sample rates have been added. The homomorphic deconvolution procedure has been improved to avoid any numerical instability. A new Piecewise Cubic Hermite Interpolating Polynomial (PCHIP) interpolation method, providing monotonic behaviour, has been introduced in the target response computation. All the interpolation and approximation procedures have been rewritten from scratch to provide better performances and accuracy.
New in Digital Room Correction (DRC) 2.6.2 (Aug 19, 2011)
- A new command line parameters replacement functionality has been introduced. The dip and peak limiting procedures have been improved in order to avoid numerical instabilities. A new wavelet based analysis graph has been added to the sample results. Many performance improvements have been introduced. A new optional parameter used to define the base directory for all files has been added.
New in Digital Room Correction (DRC) 2.6.1 (Aug 19, 2011)
- Minor corrections and improvements have been applied to the documentation and to the pre-echo truncation inversion procedure. A new target transfer function definition procedure based on Uniform B Splines has been introduced. The development environment has been moved to Code::Blocks and GCC/MinGW.
New in Digital Room Correction (DRC) 2.6.0 (Aug 19, 2011)
- A new prefiltering curve based on the bilinear transformation has been introduced. An improved windowing of the minimum phase filters used to apply the target frequency response and the microphone compensation has been implemented. A missing normalization of the minimum phase correction filter has been added. A new logarithmic interpolation has been added to the target transfer function computation. The new interpolation method simplifies the definition of the target transfer functions. Small improvements to the documentation and to the Octave scripts used to generate the graphs have been applied. A new improved version of the measurejack script has been included in the package. Some new sample configuration files, including one approximating the ERB psychoacoustic scale, have been added.
New in Digital Room Correction (DRC) 2.5.1 (Aug 19, 2011)
- Small improvements to the documentation and to the Octave scripts used to generate the graphs. The sliding lowpass prefiltering procedure has been rewritten to make it a bit more accurate and to make the code more readable. Few other minor bugs have been fixed.
New in Digital Room Correction (DRC) 2.5.0 (Aug 19, 2011)
- With version 2.5.0 a general overhauling of the filter generation procedure has been performed. Some steps (peak limiting for example) have been moved to a different stage of the procedure, and new stages have been added.
- A new ringing truncation stage has been added to remove excessive ringing caused sometimes by the pre-echo truncation procedure. Now the filter impulse response is enclosed in a sort of psychoacoustic jail that prevent, or at least reduces a lot, any artifact that could arise as a side effect of the filter generation procedure. With this changes DRC becomes somewhat “self tuning” and now it is able to adapt itself to the input impulse response, at least to some extent, providing as much correction as possible without generating excessive artifacts.
- The postfiltering stage, where the target transfer function is defined, has been split to provide a separate stage for microphone compensation. This allows for a greater flexibility defining both the target transfer function and the microphone compensation, and provides as a side effect correct test convolutions even when microphone compensation is in place. With the previous versions the test convolution was improperly altered by the microphone compensation, because both the target transfer function and the microphone compensation were generated and applied using the same filter.
- Many other procedures have been refined. For example the peak and dip limiting procedures now ensure continuity up to the first derivative of the magnitude response on the points where the magnitude limiting starts its effect. This further reduces the ringing caused by abrupt changes in the magnitude response.
- Finally many other minor bugs have been corrected and the documentation has been improved, switching to LATEX for document generation and formatting.
New in Digital Room Correction (DRC) 2.4.2 (Aug 19, 2011)
- Version 2.4.2 added a better handling of underflow problems during homomorphic deconvolution. Some little speed improvements have been also achieved. Added search and output of peak value and peak position into lsconv.