The basic way to calculate your maximum heart rate is to subtract your age from 220. For example, if you're 45 years old, subtract 45 from 220 to get a maximum heart rate of 175.
If you have an eighth-inch jack, all you've got to do is plug it into this port and start testing sound. 1  If you have a USB jack on the end of your microphone, most computers will have two or more USB ports on the side, or the back of the computer. 2  Simply plug the USB jack into one of these ports.
Method 1 USB speakers. Locate the USB slot on your PC, Mac, or Linux. Plug the USB connector into the slot. It will not work backwards, so find the right way. Set the speakers to a comfortable volume using the computer's volume system or the dial or wheel on the actual speaker(s).