The phrase "large magnet" refers to a strong and powerful magnet that is bigger in size than regular magnets. It can attract or pull objects made of magnetic materials towards it because of its strong magnetic field. Full definition
However, such instruments are very expensive because they rely on large magnets to provide strong signals. (york.ac.uk)
The sound bar houses a digital amp and two 2-1/8 - inch cone speakers with large magnets that delivers great sound quality. (cultofmac.com)
The measurements showed that the electrons interacted magnetically just as two large magnets do: Their north poles repelled one another, rotating on their axes until their unlike poles drew near. (sciencedaily.com)