Required Tools
To tune a high tension snare drum, you just need two basic tools. A drum key is used to adjust the tension of the drum while you continually test the sound of it. The second tool is a ruler, which is used to ensure that the drum is evenly adjusted at all of its tension points. If you don't have a drum key, they can be obtained inexpensively at most music retail stores and hobby shops.
Snare Disassembly
The first step of tuning a high tension snare drum is removing the top of the drum, known as its tophead, by unscrewing the tension rods that run along the rim of the drum. You can save yourself some time by just leaving the tension rods in and not removing them and only fully loosening them. You then use the ruler to check for tension equality across the drum by measuring the distance between the edge where the counter-hoop is located and the top of the drum's lug. Use this measurement as the tension length standard and adjust the tension accordingly.
Bottomhead Adjustment
After you adjust the tension on the snare drum's tophead, the tophead is reinstalled and the bottomhead is removed in the same manner. The ruler is used to guide the measurement standard for the bottomhead's tension. Once completed, the pitch of the bottomhead should sound a fourth to fifth higher than the drum's tophead when hit directly with a drum stick. The bottomhead is then reinstalled on the drum before the final tuning is done.
Snare Fine Tuning
After the drum has been reassembled and the tension has been set, you can start to fine tune the high tension snare drum. The snare is continually hit with a drum stick while the drum key is used to adjust the pitch of the drum until the desired sound is achieved. During this final step, it's important not to over-adjust the drum as you tune it. You can get better results and achieve a better high-tension sound by doing minute adjustments.