Yes, a 6.5 speaker can produce deep bass but, the capacity of a 6.5-inch speaker to produce deep bass depends upon various factors. The factors that influence the capacity of the speaker to produce deep bass encompasses the speaker's design, materials employed, and enclosure in which it is fitted. To produce deep bass, the speaker must be capable of moving a great volume of air. Hence, the speaker's diameter plays a pivotal role in deep bass production. The greater the diameter, the better the bass. Additionally, the materials used in a 6.5 speaker's construction also determine the bass. Constructing the speaker with high-quality materials such as reinforced cones, larger voice coils, and stronger magnets can enhance the speaker's ability to move a larger volume of air, enabling it to produce deeper bass.