Set direct link to default img in Redux options panel

Building a site using Redux Options Framework and want to set to a default img for a media array.
Should I use 'get_bloginfo('stylesheet_directory')' to link to theme files (as below), or should I use something else?

                        'id'       => 'img-one',
                        'type'     => 'media',
                        'url'      => true,
                        'title'    => __('Media w/ URL', 'exp_theme'),
                        'desc'     => __('Basic media uploader with disabled URL input field.', 'exp_theme'),
                        'subtitle' => __('Upload any media using the WordPress native uploader', 'exp_theme'),
                        'default'  => array(
                            'url'=> get_bloginfo('stylesheet_directory') .'/img/default-img.png'