Pontoon bridge Roman Emperor crossed the Adige in 1157 on a pontoon bridge built in advance by the people of Verona on orders of the German Emperor. The French Royal Army of King Philip II of France constructed a pontoon bridge across the Seine to seize Les Andelys from the English at the Siege of Château Gaillard in 1203. During the Fifth Crusade, the Crusaders built two pontoon bridges across the Nile at the Siege of Damietta (1218-1219), including one supported by 38 boats. On 27 May 1234, Crusader troops crossed the river Ochtum in Germany on a pontoon bridge during the
Acoustic suspension acoustic suspension, with a separate, sealed air-space, even if the woofer itself is not. One notable exception to this was the Sonus Faber Stradivari Homage which uses a ported enclosure for the midrange. The two most common types of speaker enclosure are acoustic suspension (sometimes called pneumatic suspension) and bass reflex, so they are worth comparing. In both cases, the tuning affects the lower end of the driver's response but above a certain frequency, the driver itself becomes the dominant factor and the size of the enclosure and ports (if any) become irrelevant. In general, acoustic suspension systems (driver +