How do I say WHERE (a = 1 OR b =1 ) AND (c = 1 OR d = 1)
For more complicated queries am I supposed to use raw SQL?
Make use of Parameter Grouping (Laravel 4.2). For your example, it'd be something like this:
Model::where(function ($query) {
$query->where('a', '=', 1)
->orWhere('b', '=', 1);
})->where(function ($query) {
$query->where('c', '=', 1)
->orWhere('d', '=', 1);
});