Yes you can, I got a warning from an officer for playing my stock radio and speakers to loud with the top down. Best thing to do is when you see a police officer rolling behind you or towards you to turn it down (I'm assuming you had it cranked up and he heard you). The cop that warned me happened to roll up from behind me at night and I had the top down and he had his windows down and I guess he didn't care much for my choice of music.
2008 Lincoln MKZ
1995 Mustang GT Convertible
2002 F-150 SuperCrew
It depends on the city your in and their noise ordiances. Like Kaufman has a 50ft noise ordinace, if it can be heard by a cop at 50ft from the road while your driving by, they can give you a ticket if they want.