Which disadvantage is primarily cited for mechanical modulators compared to electrical modulators?

Mechanical modulators often rely on physical components and structures, such as diaphragms and mechanical linkages, to modulate signals. This approach can lead to location dependency issues for microphones used with these modulators. If the microphone is not optimally placed relative to the mechanical modulator, the performance of the system can be adversely affected, resulting in variable audio quality depending on the positioning.

In contrast, electrical modulators do not depend on the physical placement of components to the same extent, making them more flexible in their applications. They can maintain consistent performance across different setups without the concern of specific spatial arrangements. This inherent limitation in mechanical modulator design is what primarily differentiates it from electrical alternatives.

The other options present considerations that are not as central to the operational characteristics of mechanical modulators in comparison to electrical ones. Higher costs, setup times, and compatibility with digital systems can vary significantly based on specific designs and technologies, but the location dependency of the microphone remains a distinct and defining disadvantage of mechanical modulation methods.