From a cop's perspective, I suspect they are not going to be sympathetic to you, Alex. If you call them to enforce the ordinance, they will probably look at the first one, find out if the activity is within the time and day limitations, and depart. They are NOT going to get a decibel meter or do a lot of research on this.
Now, if they refuse to act on the city ordinance, you can always insist upon signing a citizen's arrest for disturbing the peace per PC 415. Now, THAT would go over well with the neighbor as that would either result in a citation to appear in court (and you would have to go as well), or he would be booked into jail (and both of you would still eventually have to go to court). Is it worth that kind of problem?
And as for those bashing California, remember that most of this state is agricultural and rural. While most the people live along the liberal coast in urban clusters, most of the state is rural. I live in such a community where a neighbor is likely to step outside to help his neighbor. The only calls I have gotten about such noise complaints is when the activity is going on after dark or begins in the wee hours of the morning. It is NOT a problem here that my town does not even HAVE such a noise ordinance ... it has never been an issue!
