Show custom posts with a specific “custom TAXONOMY slug” on startpage

For taxonomy superevent and term true:

add_action('pre_get_posts','wpse57309_alter_front_page_query');
function wpse57309_alter_front_page_query( $query ){
     if( $query->is_main_query() && is_front_page() ){
         if( !$query->get('post_type') ){
            //post type is not set, the default will be an array of them:
            $query->set( 'post_type', array( 'news', 'events', 'tv' ) );
            $query->set( 'superevent', 'true' );
         }
     }
}