 While boxed hi-fi speakers are often described as being acoustic suspension, or ported (bass reflex) depending on the absence or presence of a port tube/vent, it is also true that in typical box speakers with more than two drivers, the drivers between the woofer and tweeter are usually designed as 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.