How Do You Convert Milliseconds to Samples?

Delay some recording equipment to improve sound quality

When recording multiple sources—and especially in live recording situations—you sometimes need to apply a software-based sample delay to align those multiple sources and adjust for the amount of latency. Usually, these types of delays are set in milliseconds in order to make the calculations easy on you—1 millisecond roughly equals 1 foot of distance. But some software packages don't offer a millisecond option.

You'll have to do the math yourself, but this is one cost-free way to improve your recording experience.

Converting to Samples in the Studio

To calculate sample length in milliseconds, you first need to know the sample rate of the recording you're mixing. For example, say that the recording you're mixing is at 44.1 kHz, which is standard CD-quality. If you're mixing at 48 kHz or 96 kHz, use that number.

The formula is simple. It is:

  • Milliseconds times Sample rate = Samples

In the example, if the delay between a pair of room microphones and a soundboard feed in your home studio is 17 milliseconds of delay (based 17 feet of distance), the formula becomes:

  • 17 times 44.1 = 749.7 samples

In this case, you enter a sample delay of 749.70 samples into the software for the closest source to time-align the sources.

It's equally easy to calculate how many milliseconds are in a number of samples. In this case, you use the following formula:

  • Samples divided by Sample rate = Milliseconds

Using the example, you divide 749.70 by 44.1, which brings us back to the original number, 17 milliseconds.

Using these simple formulas, you can easily hand-calculate the relationship between samples and milliseconds, which may come in handy when mixing in your home studio.

Delays in Live Performance

Sometimes at live performances, speakers are arranged at various distances from the stage on the walls of the auditorium. The delay of the sound coming from the stage mixed with the un-delayed sound coming from the speaker on the wall near you can cause sound muffling and degrade your listening experience. This is avoided when the sound technician (or you if it is your band) enters a delay in the speakers based on how far they are positioned from the stage in feet, remembering that 1 foot of distance equals approximately 1 millisecond.