diff --git a/tests/test_audio.py b/tests/test_audio.py
index 7f884d37..f006e63e 100644
--- a/tests/test_audio.py
+++ b/tests/test_audio.py
@@ -140,3 +140,24 @@ class TestAudio(unittest.TestCase):
         assert x_norm.min() < 0, x_norm.min()
         x_ = self.ap._denormalize(x_norm)
         assert (x - x_).sum() < 1e-3
+
+    def test_scaler(self):
+        scaler_stats_path = os.path.join(get_tests_input_path(), 'scale_stats.npy')
+        conf.audio['stats_path'] = scaler_stats_path
+        conf.audio['preemphasis'] = 0.0
+        conf.audio['do_trim_silence'] = True
+        conf.audio['signal_norm'] = True
+
+        ap = AudioProcessor(**conf.audio)
+        mel_mean, mel_std, linear_mean, linear_std, _ = ap.load_stats(scaler_stats_path)
+        ap.setup_scaler(mel_mean, mel_std, linear_mean, linear_std)
+
+        self.ap.signal_norm = False
+        self.ap.preemphasis = 0.0
+        
+        # test scaler forward and backward transforms
+        wav = self.ap.load_wav(WAV_FILE)
+        mel_reference = self.ap.melspectrogram(wav)
+        mel_norm = ap.melspectrogram(wav)
+        mel_denorm = ap._denormalize(mel_norm)
+        assert abs(mel_reference - mel_denorm).max() < 1e-4
\ No newline at end of file
diff --git a/tests/test_config.json b/tests/test_config.json
index 6d63e6ab..e9cd48cf 100644
--- a/tests/test_config.json
+++ b/tests/test_config.json
@@ -2,10 +2,12 @@
     "audio":{
         "audio_processor": "audio",     // to use dictate different audio processors, if available.
         "num_mels": 80,         // size of the mel spec frame. 
-        "num_freq": 1025,       // number of stft frequency levels. Size of the linear spectogram frame.
+        "num_freq": 513,       // number of stft frequency levels. Size of the linear spectogram frame.
         "sample_rate": 22050,   // wav sample-rate. If different than the original data, it is resampled.
-        "frame_length_ms": 50,  // stft window length in ms.
-        "frame_shift_ms": 12.5, // stft window hop-lengh in ms.
+        "frame_length_ms": null,  // stft window length in ms.
+        "frame_shift_ms": null, // stft window hop-lengh in ms.
+        "hop_length": 256,
+        "win_length": 1024,
         "preemphasis": 0.97,    // pre-emphasis to reduce spec noise and make it more structured. If 0.0, no -pre-emphasis.
         "min_level_db": -100,   // normalization range
         "ref_level_db": 20,     // reference level db, theoretically 20db is the sound of air.
@@ -15,8 +17,8 @@
         "symmetric_norm": true, // move normalization to range [-1, 1]
         "clip_norm": true,       // clip normalized values into the range.
         "max_norm": 4,          // scale normalization to range [-max_norm, max_norm] or [0, max_norm]
-        "mel_fmin": 95,         // minimum freq level for mel-spec. ~50 for male and ~95 for female voices. Tune for dataset!!
-        "mel_fmax": 7600,        // maximum freq level for mel-spec. Tune for dataset!!
+        "mel_fmin": 0,         // minimum freq level for mel-spec. ~50 for male and ~95 for female voices. Tune for dataset!!
+        "mel_fmax": 8000,        // maximum freq level for mel-spec. Tune for dataset!!
         "do_trim_silence": false
     },