After several options, I stopped at the next one, put two pieces of synthetic winterizer, one above the factory piece, the other below nothing glued the synthetic winterizer, it clings well to the walls, the size is about 70 * 70 centimeters, the thickness is 3 centimeters opposite the speakers, I also laid a little cotton wool, the Mid-range speaker cap also opened and added a little cotton wool. / Синтепон в акустику и сабвуфер Yamaha