The Measurements Panel shows the measurements which have been made or
loaded and information about them. The tabs on the panel are used to select
individual measurements, they include a thumbnail of the frequency response
(this can be hidden by unchecking the box in the View
settings).
The measurement info can be hidden to provide more screen area for the
graph, click the chevrons in the top left of the panel to hide or show the
panel contents
The text box at the top of the measurement panel is used to change the
name of the measurement. The length of the name is limited to the width of
the box. If a blank name is entered, "No Description" is used.
The buttons next to the name box are used to set the trace colour, save the measurement and delete the measurement (deleting a measurement removes it from REW, saved measurement files are not affected). Trace colors can be reset to their defaults in the View settings.
Notes relating to each measurement can be entered in the notes area, they
are saved with the measurement
Right-clicking on the tab for a measurement brings up a menu to save,
export or delete
The Details panel shows additional information about the measurement.
The date and time of the measurement are shown in the Details panel header,
if the mouse pointer is hovered over the header a tooltip appears with further
information
If the measurement has been made using the left channel as a reference (see Soundcard Settings REW calculates the delay through the system being measured and shows it in the Details panel as "System Delay" in milliseconds. If the mouse pointer is hovered over the delay value a tooltip appears showing the equivalent distance in feet and metres.
The Trace Adjustments panel has controls to smooth the frequency responses
and to shift frequency response trace positions vertically on the graphs.
Trace Offset allows the position of the frequency
response trace to be shifted. This only affects the position of the trace
on the graphs, not the actual data values. To change the data values by the
offset amount (which is in dB), use the Add Offset To Data action.
The frequency response traces may be smoothed by fractional octave
averaging. This is mainly used for full range measurements, as reflections
can cause severe comb filtering which makes it difficult to see the underlying
trend of the response. It would very rarely be used for low frequency measurements
as it would obscure the true shape of the response and so not allow
accurate correction filters to be determined.
The Target Settings panel is used to define the shape of the idealised
response for a measurement, which typically corresponds to the shape of
the bass management curve for the speaker being measured. The level at
which the Target Response is drawn on the graph can be adjusted manually
or estimated by REW using the Set Target Level action.
The Speaker Type for the measurement can be set to "Full Range" (often referred to as "Large"), "Bass Limited" (often referred to as "Small"), "Subwoofer" and "None". This selects the corresponding bass management filter shape (high pass, low pass or no filter as appropriate).
The Crossover setting specifies the slope of the bass management filter in dB/octave. Typically this would be 24dB/octave for a subwoofer and 12dB/octave for a bass limited speaker, however the 12dB/octave figure for a speaker is used because the speaker itself is expected to have around a 12dB/octave acoustic roll-off, hence the overall effect is around 24dB/octave - the 24dB setting may be a better match to the measured response in those cases.
The Cutoff specifies the bass management filter cutoff frequency in Hz, typically 80Hz in Home Theatre systems.
The default speaker type, crossover slope and cutoff to use for new measurements are specified in the Analysis settings.
Set Target Level is used to measure the SPL the channel being measured produces when fed with a pink noise calibration signal at the measurement Sweep Level. The resulting SPL then becomes the target level for the measurement for subsequent filter adjustments.
The Filter Tasks panel contains controls for finding peaks in the frequency
response, assigning filters to correct them and optimising the shapes of
those filters. The steps are described in detail in the
Filter Adjustment help.