What type of waves are characterized as having a pH lower than alkaline waves but higher than true acid waves?

The answer is acid balanced waves. Acid balanced waves are specifically formulated to have a pH that is lower than alkaline waves but higher than true acid waves, situating them in a middle ground. This specific pH level allows for a controlled chemical reaction and provides a balance that is more compatible with various hair types.

These waves use a combination of heat and chemically adjusted pH to create curls or waves, allowing for a more gentle approach to permanent waving while still being effective. The pH balance helps in minimizing damage to the hair cuticle, making them suitable for a wider range of hair conditions compared to other types of waves.

In contrast, neutral waves, low-pH waves, and cold waves do not fit within this specific pH framework, making acid balanced waves the appropriate choice in this context.