From eedd6d83b4a2b65f4fbb269631ab5188a6670243 Mon Sep 17 00:00:00 2001
From: Casper <c.jansen@ascee.nl>
Date: Thu, 5 Jan 2023 17:06:32 +0100
Subject: [PATCH] Improved handling of EQ when fs=44.1k a bit, including
 suggestion to use 48k

---
 src/lasp/filter/filterbank_design.py | 52 ++++++++++++++--------------
 1 file changed, 26 insertions(+), 26 deletions(-)

diff --git a/src/lasp/filter/filterbank_design.py b/src/lasp/filter/filterbank_design.py
index 777b720..5370725 100644
--- a/src/lasp/filter/filterbank_design.py
+++ b/src/lasp/filter/filterbank_design.py
@@ -85,8 +85,8 @@ class FilterBankDesigner:
             if self.nominal_txt(x) == nom_txt:
                 return x
         raise ValueError(
-            f'Could not find a nominal frequency corresponding to {nom_txt}. Hint: use \'5k\' instead of \'5000\'.'
-        )
+            f'Could not find a nominal frequency corresponding to {nom_txt}. '
+            'Hint: use \'5k\' instead of \'5000\'.')
 
     def sanitize_input(self, input_):
         if isinstance(input_, int):
@@ -254,8 +254,8 @@ class FilterBankDesigner:
             for i, x in enumerate(range(xl, xu + 1)):
                 fl = self.fl(x)
                 fu = self.fu(x)
-                # Find the indices in the frequency array which correspond to the
-                # frequency band x
+                # Find the indices in the frequency array which correspond to
+                # the frequency band x
                 if x != xu:
                     indices_cur = np.where((freq >= fl) & (freq < fu))
                 else:
@@ -337,13 +337,13 @@ class OctaveBankDesigner(FilterBankDesigner):
 
         Args:
             x: Filter offset power from the reference frequency of 1000 Hz.
-            filter_class: Either 0 or 1, defines the tolerances on the frequency
-            response
+            filter_class: Either 0 or 1, defines the tolerances on the
+            frequency response
 
         Returns:
-            freq, llim, ulim: Tuple of Numpy arrays containing the frequencies of
-            the corner points of the filter frequency response limits, lower limits
-            in *deciBell*, upper limits in *deciBell*, respectively.
+            freq, llim, ulim: Tuple of Numpy arrays containing the frequencies
+            of the corner points of the filter frequency response limits, lower
+            limits in *deciBell*, upper limits in *deciBell*, respectively.
         """
         b = 1
 
@@ -450,8 +450,8 @@ class OctaveBankDesigner(FilterBankDesigner):
         if int(self.fs) in [44100, 48000, 96000]:
             return 1.0
         else:
-            raise ValueError('Unimplemented sampling frequency for SOS'
-                             'filter design')
+            raise ValueError('Unimplemented sampling frequency \'{} Hz\' for '
+                             'SOS filter design. Try 48 kHz.'.format(self.fs))
 
     def sosFac_u(self, x):
         """Right side percentage of change in cut-on frequency for designing
@@ -463,8 +463,8 @@ class OctaveBankDesigner(FilterBankDesigner):
         if int(self.fs) in [44100, 48000, 96000]:
             return 1.0
         else:
-            raise ValueError('Unimplemented sampling frequency for SOS'
-                             'filter design')
+            raise ValueError('Unimplemented sampling frequency \'{} Hz\' for '
+                             'SOS filter design. Try 48 kHz.'.format(self.fs))
 
 
 class ThirdOctaveBankDesigner(FilterBankDesigner):
@@ -511,13 +511,13 @@ class ThirdOctaveBankDesigner(FilterBankDesigner):
 
         Args:
             x: Filter offset power from the reference frequency of 1000 Hz.
-            filter_class: Either 0 or 1, defines the tolerances on the frequency
-            response
+            filter_class: Either 0 or 1, defines the tolerances on the
+            frequency response
 
         Returns:
-            freq, llim, ulim: Tuple of Numpy arrays containing the frequencies of
-            the corner points of the filter frequency response limits, lower limits
-            in *deciBell*, upper limits in *deciBell*, respectively.
+            freq, llim, ulim: Tuple of Numpy arrays containing the frequencies
+            of the corner points of the filter frequency response limits, lower
+            limits in *deciBell*, upper limits in *deciBell*, respectively.
         """
 
         fm = self.G**(x / self.b) * self.fr
@@ -605,16 +605,16 @@ class ThirdOctaveBankDesigner(FilterBankDesigner):
         # Idea: correct for frequency warping:
         if np.isclose(self.fs, 48000):
             return 1.00
-        elif np.isclose(self.fs, 41000):
-            warnings.warn(
-                f'Frequency {self.fs} might not result in correct filters')
-
+        elif np.isclose(self.fs, 44100):
+            warnings.warn(f'Sampling frequency {self.fs} Hz might result in '
+                          'incorrect filters')
             return 1.00
         elif np.isclose(self.fs, 32768):
             return 1.00
         else:
-            raise ValueError('Unimplemented sampling frequency for SOS'
-                             'filter design')
+            raise ValueError('Unimplemented sampling frequency \'{} Hz\' for '
+                             'SOS filter design. Try 48 kHz.'.format(self.fs))
+
     def sosFac_u(self, x):
         """Right side percentage of change in cut-on frequency for designing
         the filter."""
@@ -623,5 +623,5 @@ class ThirdOctaveBankDesigner(FilterBankDesigner):
         elif np.isclose(self.fs, 32768):
             return 1.00
         else:
-            raise ValueError('Unimplemented sampling frequency for SOS'
-                             'filter design')
+            raise ValueError('Unimplemented sampling frequency \'{} Hz\' for '
+                             'SOS filter design. Try 48 kHz.'.format(self.fs))