FORT WORTH - The beat from a custom-built speaker rattles your ribs, and Toby Guynn just smiles.

No one appreciates a pounding subwoofer more than Toby.

In his laboratory of switches, dials and diaphragms, he looks and acts a little like the professor from the film “Back to the Future.”

And according to critics, he builds some of the best subwoofers in the world in his little Fort Worth shop. They’re about the size of rolling suitcases.

Most of his customers buy one or two to put in their cars.

Guynn holds a piece of paper over the speaker opening. Sound waves shred the paper.

It’s fun in the lab, but out on the streets, where people are walking or trying to hear their own car radios, Fort Worth police lieutenant Paul Henderson says it’s against the law. "That is considered a breach of the peace. Disorderly conduct. Noise," he said.

Thursday night Fort Worth police actually pulled over and ticketed a driver for blaring his radio. Guynn isn’t surprised. "I remember one customer who was actually bragging because he said he got a ticket for his stereo, which he said was $250."

Expect more noise tickets as complaints rise, mainly from residents moving downtown into an entertainment district that's naturally louder than the suburbs.

A city committee is studying the problem. As a result, police are issuing more tickets for loud music, for flagrantly revving motorcycle engines, and for subwoofers, whose ultra-low waves penetrate walls.

Lieutenant Henderson says, "It's difficult to enforce because it's subjective."

To make it more objective, Fort Worth police are testing noise meters that specifically measure sound levels from subwoofers.

Even Toby Guynn concedes, "I guess there are limits to it.”

E-mail jdouglas@wfaa.com.