Why my 16000 speech instance get poor performance?

[JohnHerry]

Thanks for the good job.
We are finding a vocoder for TTS, we tried the SawSingSub, our audio sample rate is 16000, to cooperate with our acounstic model, I had changed the params in preprocess.py, set hop_length=200, win_length=800, n_mel_channels=80, I also changed the , sawsingsub.yaml, accordingly , set block_size = 200, left other settings unchanged.

I have trained the model for nearly 1 million steps, but the quality of generated waveform is far worse then that of HiFi-GAN with the same steps, Is there any parameter adjustments I had missed?

The Blured Spectrogram of SawSingSub generated speech