Overview
Intermodulation (a.k.a. intermod) is the unintentional mixing of frequencies in a nonlinear device, such as an amplifier or mixer. Intermod products (resultant frequencies) are calculated by adding and subtracting the input frequencies and their harmonics.
Here's a Wikipedia article.
This calculator computes intermod for RF signals. It could be used for audio signals as well, but the expression of frequencies in MHz isn't helpful in that case.
Limitations
The free version of this calculator has the following limitations:
- Unlimited number of transmit and receive frequencies
- Up to three transmitters combined at a time
- Up to fifth order intermod
- User-specified minimum and maximum number of combined transmitters
- User-specified minimum and maximum intermod order
- Ability to calculate only odd or even orders
- Ability to denote half-duplex tx/rx pairs
- API access