Keeps the front-end admin bar hidden for subscriber accounts while leaving it available for editors and administrators.
add_filter( 'show_admin_bar', 'wpfolks_hide_admin_bar_for_subscribers' );
function wpfolks_hide_admin_bar_for_subscribers( $show ) {
if ( current_user_can( 'subscriber' ) && ! current_user_can( 'edit_posts' ) ) {
return false;
}
return $show;
}