Mulitple Authors – different sidebars

Creating a blog that has four different authors. I want to show a different sidebar for:
-author 1 archive & author 1 post(same sidebar)
-author 2 archive & author 2 post(same sidebar)
-author 3 archive & author 3 post(same sidebar)
-author 4 archive & author 4 post(same sidebar)
-home, category and tag (same sidebar)

I’ve tried:

<?php $post = $wp_query->post;?>

<?php if ( $post->post_author == '1') { ?>
    hello author 1

<?php } elseif ( $post->post_author == '2') { ?>
    hello author 2

<?php } elseif ( $post->post_author == '3') { ?>
    hello author 3

<?php } elseif ( $post->post_author == '4') { ?>
    hello author 4

<?php } else { ?>
    default sidebar

<?php } ?>

But doesn’t work. Only shows sidebar for author post, not author archive or any other pages.

Any help would be greatly appreciated.

Thanks
Steve