Another trick to make a weak boombox sound like it is a lot more powerful is to add an external soundbox. This can be achieved at zero cost by placing the boombox into any receptacle just larger than its size, a bit taller, and like 20-50 cm deeper than the boombox itself, keeping the player inside still near the opening. Wood furniture works really well for this, and floor level is preferable since it would help further bass frequencies.
That's true, this would allow you to build a compromise antenna that works reasonably well over a range of frequencies without being tuned. On a Yagi you could probably achieve that by purposefully varying the distance between the resonators a bit from ideal, correct?
