Someone

$media_count is a numbered list generated from theme_settings and themename.info using: 

  $grid = aether_grid_info();
  if (theme_get_setting('responsive_enable')) {
  $media = array();
  $media_queries = theme_get_setting('media_queries');
    if ($media_queries && is_numeric($media_queries)) {
      for ($i = 1; $i <= $media_queries; $i++) {
        $media[] = 'medium' . $i;
      }
    }
  }
  else {
    $media = array(t('Default'));
    $media_queries = 1;
  }

  for ($media_count = 1; $media_count <= $media_queries; $media_count++) {
    $medium = $media[$media_count-1];


function aether_preprocess_page(&$variables, $hook) {

    $base_grid_prefix = $grid["prefix{$media_count}"];
    $grid_width = $grid["width{$media_count}"];
    $variables['grid_width'] = $base_grid_prefix . "$grid_width ";

}

page.tpl.php

<div class="header-inner <?php print $variables['grid_width']; ?>">