In iTunes 11, users can still allowed to make ringtones with 40-second in length and text tones or alert tones in 2-5 seconds or 5-30 seconds for iPhone 5, iPhone 4S, iPhone 4, iPhone 3GS and iPhone 3G. The article below introduces a step-by-step on how to custom your own ringtones, text tone or alerts within 40 seconds in iTunes 11.

http://www.techisky.com/how-to/create-ringtones-textones-alerts-in-itunes11.html

If you want to make ringtones or alerts longer than 40 seconds, you can free download the awesome iPhone Ringtone Maker from TechiSky.