Thanks theaudiotweak… But my result obtained only with water are enough for the day and extraordinary... I am very pleased already, the helmhotz resonator are not snake oil,pricing sometimes is, ideas are often implemented with very low cost and sufficient good result... I will not purchase audiophile resonators, I am proud of my cheap ones and astounded... Perhaps I will try olive oil some day to comes thanks Tom for the idea... Thanks also to Geoff for his impulse and astute observations...