With the introduction of Motorola's new line of trendy cell phones, the C330 series, in 2002, came a new concept: audio mixers, that allow you to mix various preset rythms and sounds to create your own polyphonic ringtone. Now, we're seeing audio mixers in more new phones, such as the Siemens M56. Your good old polyphonic ringtones are also going to evolve.

One of the first phones to include the capacity to play polyphonic ringtones, the Sanyo SCP-5000, was only able to play 4 notes at the same time, it had a 4-chord ringtone engine. Quickly, new phones were able to play 16 notes at the same time and now, we're seeing 40-chord polyphonic ringtones in the most recent phones. These channels are used to play various notes with some of the hundreds of music instruments included in the MIDI music format. But the goal is not necessarily to actually play 40 notes at the same time.

In fact, ringtone creators will increasingly use these channels to add special effects such as echoe, reverb, or portamento. The most evolved ringtone engines, the SMAF chipset from Yamaha, also let ringtone creators mix real audio clips with MIDI instruments.