How to set the default avatar of buddypress avatar

Question

I need a way to set the default avatar for buddypress's bp_core_fetch_avatar. Using the regular get_avatar you can just set the $default path but I can't find anyway to do it with buddypress's function. For instance, I use this function to get the full size avatar for a post author but adding default => "mysite.com/default.png" doesn't pass.

function fod_post_author_avatar() {
global $post;

if ( function_exists('bp_core_fetch_avatar') ) {
    echo apply_filters( 'bp_post_author_avatar', bp_core_fetch_avatar( array( 'item_id' => $post->post_author, 'type' => 'full', 'width' => "130px", 'height' => "130px", default => "http://mysite.com/wp-content/themes/123/images/default-avatar.png" ) ) ); 
} else if ( function_exists('get_avatar') ) {
    get_avatar();
}
}

Answer 1

I need a way to set the default avatar for buddypress's bp_core_fetch_avatar.

Why?

adding default => "mysite.com/default.png" doesn't pass

There is no 'default' option in that BP function http://phpxref.ftwr.co.uk/buddypress/nav.html?bp-core/bp-core-avatars.php.source.html#l78

You can define the default avatar site-wide by using BP_AVATAR_DEFAULT