If you don't know how discount codes work on the Exponential Audio webstore, then here's a simple guide:
First, place any articles you need into your cart. Your cart will look something like this:
Look on this window about halfway down on the left. You'll see the phrase "Got a code?"
Click directly on the phrase.
As soon as you click on "Got a code?" you'll see it's been replaced by a box in the same position.
Paste your code into this box. It's really better to paste the code than to type it in.
Once you've pasted in the code, you'll see the phrase "update" just to the right of the code.
Click on the phrase "update"
As soon as you've clicked on "update" you'll see the discount applied and your new total will appear.
Go on to checkout and complete your purchase