I've an old pair of Wharfedale model 507 speakers. Between us I'm not getting the high frequencies I need. I'm prepared to dive into the cabinets but cannot find any access route at all. Help!?

 

Remove the screws that hold the bass drivers in place. Carefully pry out the bass driver. Inspect the interior though this hole,and go from there.

 

You can send the old tweeters back to Wharfedale and get them fixed. I didthis aabout 15 years ago, cost was £13.
Frank