Which of the following is true about conventional dimmers?

Conventional dimmers are indeed typically simpler and less flexible compared to more advanced dimming technologies such as digital dimmers or intelligent control systems. These dimmers work by directly altering the voltage supplied to the lighting fixture, which can limit their functionality and versatility. They often involve straightforward design and operation, making them easier to install and use but less adaptable to complex lighting setups or demands for precise control.

For instance, while conventional dimmers can control incandescent and some other types of light sources effectively, they don't provide the same level of programmable features or remote control capabilities that more advanced dimming systems offer. This simplicity can be advantageous in straightforward applications but also means that users might find limitations with customizing or enhancing lighting effects for more elaborate productions or environments.

The other options presented don't accurately describe conventional dimmers. They do produce heat due to the energy loss in the form of heat during the dimming process. They generally do not require specialized wiring, as they can be installed in standard electrical circuits. Lastly, conventional dimmers are often less energy-efficient compared to newer technologies, as traditional types waste energy in heat rather than converting it to usable light.