John Mulcahy
REW Author
Thread Starter
- Joined
- Apr 3, 2017
- Messages
- 7,296
REW V5.20.5 is now available on the REW site. There are a few feature additions and a collection of bug fixes.
Feature additions and changes
Bug fixes:
Feature additions and changes
- The room simulator graph end frequency has been increased from 200 Hz to 300 Hz. To keep the UI responsive to changes for very large rooms the maximum mode order is limited to the 20th in each axis, rooms with dimensions large enough to reach that limit will have a correspondingly lower end frequency for their responses
- A Speaker Positions pane has been added to the room simulator that lists the positions of all the sources
- There is an RTA distortion setting to choose whether to use the AES17-2015 standard notch for the fundamental power. If the Use AES17-2015 standard notch option is selected the fundamental power for THD and THD+N calculations will be the power within a one octave span around the fundamental frequency. If that option is not selected it will be the power in the main lobe of the fundamental. When the fundamental level approaches the noise floor using the standard notch will produce a much higher figure than the fundamental main lobe, in those cases it is better not to use the standard notch
- A button has been added to the signal generator harmonic distortion panel to set the harmonics in opposite phase to the current RTA distortion values, providing a convenient way to produce a pre-distorted signal to cancel the distortions of a measurement system. To use it in that way make an RTA measurement of the system measuring itself, running the generator at the desired frequency and level. Coherent averaging is recommended to minimise the effects of noise on the recovered harmonics. Once stable harmonic levels and phases are seen on the RTA press the Set from RTA button. Note that all the generator distortion harmonics should be off before making the RTA measurement, the new Clear all button can be used to ensure that. Harmonics which are in the measurement noise floor should be deselected. THD improvements of around 20 dB may be achieved, but the settings are only valid at the frequency and signal level at which they were measured and will not remain valid if the measurement system distortion varies (as its temperature changes, for example). Along with that change there are now buttons on the distortion dialog to select or deselect all harmonics and the harmonic distortion levels now have one decimal place.
- There is now an option to include linearity data in distortion data exports from stepped level measurements
- A couple of seconds of dither have been added at the end of sweep files saved from the generator (if timing reference signals are included)
- There is a message to show that manual SPL calibration is not available if the mic cal file has a Sensitivity figure
- Added a "Scale overlays" option on the graph image capture dialog to scale any overlay boxes according to the chosen image graph font size
- Automatically restart the SPL meter, level meters, scope, RTA and signal generator if they were running when a different sample rate was selected
- Show the CH1 and CH2 input names in the Scope title bar
- Show 4 significant digits for impedance values
- Made crest factor minimisation optional for the periodic noise and multitone sequences, since some applications require high crest factor signals. The signal kurtosis is shown alongside the crest factor, it gives a more robust measure than crest factor for random signals whose crest factor typically increases as the duration over which it is measured is increased
- On Linux systems REW now tests for the capability to show the cursor on the surface of waterfalls and disable that feature if the system does not support it, avoiding an exception that would otherwise be generated
Bug fixes:
- Predicted measurements generated from imported data (with no IR) did not include predicted phase results
- When trace offset was adjusted the predicted SPL trace moved twice as much as it should
- Saving to an existing file did not truncate the file to the size required
- Response copy did not set the date for the copy
- If a filter set contained an all pass filter and otherwise had no net gain the all pass was not applied
- If ASIO is being used but the ASIO input has not been selected and a USB mic is connected an exception would be generated
- The room simulator responses could be off the top of the graph for very large rooms
- The RTA noise curve selection could not be changed using the mouse, only using the keyboard
- When the input options for high pass or invert were selected some components continued to use the unmodified data
- Estimate IR delay could give an incorrect result if the left hand window was wider than the right hand window
- The scope full scale lines were drawn in the wrong position when the input full scale was not 1 Vrms
- The distortion export dialog had different settings to the distortion graph and could give incorrectly scaled results for some settings. It has been made consistent with the distortion graph options.
- A division by zero error could occur on the Burst Decay spectrogram for small window settings
- A null pointer exception could occur when adding tails to a smoothed response for minimum phase generation
- Minimum phase tails did not take account of the effect of smoothing on the minimum valid frequency for the response
- The RTA graph did not update for some preference changes until the next startup
- The t=0 offset value field on the SPL & Phase graph control was too narrow on macOS
- Tones saved from the generator as 24-bit PCM had a 2nd harmonic component at approx -158 dBFS due to biased rounding
- Tones output from the generator to an ASIO driver that used a 32-bit integer sample format had a 2nd harmonic component at approx -158 dBFS due to biased conversion from float to Int32
I'll make a change so that the curves are displayed before there is RTA data to show if the mode is one octave.
