I have a good voice. I'm a tenor and I guess I have a good range. The highest note I've hit was in Vision of Love so I have some moderate access to my whistle register. For as long as I can remember, I've always had a really nasal voice. As I get older and pick up more tips by listening to different vocals, I'm starting to realize that my tone needs work. I have some tension in my voice which restricts me from leaning on my falsetto at some points or straying off key when I'm crooning. I need my tone to be... different. Sometimes it's strong and confident, other times it's soft. I'm 19, btw. I need to learn how to not be so nasal and have a more, I don't know, boyish tone. Cuz this one aint working!
Sounds like a resonance and diaphragm support problem in which your sound resonates solely in the sinuses around the nose. A lot of tenors tend to have the same problem. The sinuses should be used to adjust tone but not create it. However, keep in mind that some people have a nasal tone regardless of how they sing.
First, while you sing, make sure there are no vibrations over your eyes or around your nose. If there are, that's bad.
Second, when you sing, practice using open vowels or, in other words, drop your jaw. When you sing an 'Ah' or 'Aw' vowel, your jaw should be fully dropped and relaxed though you may feel weird doing so. The way to be sure that your jaw is fully open is to drop the jaw and find the gap between your jaw bone and skull which is somewhere around the ears (this is hard to explain without a visual); You should be able to fit your index finger in the gap.
Third, sing scales at least twice a day using a lip trill (where you blow air through your lips so that they vibrate). The lip trill is the approximate amount of air that you should be using while singing. You can also try taking a good supported breath into the diaphragm (belly button area) and exhaling on a lip trill for as long as possible. A lot of times this will make your nose tickle or itch, but that's normal.
Fourth, and perhaps most beneficial, is to practice breathing excersizes. Here is a simple one that is commonly used for those beginning vocal training: Lie down and place one hand on the small of your back and another hand on your belly button. Breathe in for 10 seconds into your hand on your belly button, be sure that the air is going right into that hand and nowhere else first. Then, without pausing to hold your breath, exhale for exactly 10 seconds so that your lungs are now empty. Do this at least 10-15 times a day. A lot of people do it as they're trying to fall asleep as it's very relaxing.
Of course, none of this is as good as working with a private tutor who can really see what your problem is and help you fix it.
