diff --git a/src/f5_tts/api.py b/src/f5_tts/api.py
index 41fc667..823067d 100644
--- a/src/f5_tts/api.py
+++ b/src/f5_tts/api.py
@@ -15,6 +15,9 @@ from f5_tts.infer.utils_infer import (
     infer_process,
     remove_silence_for_generated_wav,
     save_spectrogram,
+    preprocess_ref_audio_text,
+    target_sample_rate,
+    hop_length,
 )
 
 
@@ -31,10 +34,8 @@ class F5TTS:
     ):
         # Initialize parameters
         self.final_wave = None
-        self.target_sample_rate = 24000
-        self.n_mel_channels = 100
-        self.hop_length = 256
-        self.target_rms = 0.1
+        self.target_sample_rate = target_sample_rate
+        self.hop_length = hop_length
         self.seed = -1
 
         # Set device
@@ -97,6 +98,9 @@ class F5TTS:
             seed = random.randint(0, sys.maxsize)
         seed_everything(seed)
         self.seed = seed
+
+        ref_file, ref_text = preprocess_ref_audio_text(ref_file, ref_text, device=self.device)
+
         wav, sr, spect = infer_process(
             ref_file,
             ref_text,
diff --git a/src/f5_tts/train/finetune_gradio.py b/src/f5_tts/train/finetune_gradio.py
index fe835b2..007dad8 100644
--- a/src/f5_tts/train/finetune_gradio.py
+++ b/src/f5_tts/train/finetune_gradio.py
@@ -1216,7 +1216,7 @@ def infer(project, file_checkpoint, exp_name, ref_text, ref_audio, gen_text, nfe
     else:
         device_test = None
 
-    if last_checkpoint != file_checkpoint or last_device != device_test or last_ema != use_ema:
+    if last_checkpoint != file_checkpoint or last_device != device_test or last_ema != use_ema or tts_api is None:
         if last_checkpoint != file_checkpoint:
             last_checkpoint = file_checkpoint