The only pool room of note near Pasadena is Embassy, but it caters to the Chinese/Taiwanese crowd, so if you don't speak the language or come in with someone familiar to them, you might be inadvertently thrown in with the bangers in the back on the banger tables. Despite that, it has THE BEST equipment in southern California. It also has 10 or so 6x12 snooker tables, some great players (generally snooker players that dabble in pool, not quite pros, but a few will surprise you), and a great menu if you like Chinese food.
If you don't feel comfortable walking into a room like that or simply want to find actual pros, your best bet is Hardtimes, which shouldn't take more than 30 minutes as long as you don't get stuck in traffic. There, Dave Hemmah is the house pro and quite a few others drop in from time to time.