iMovie is a wonderful free video editing software that comes as standard with an Apple Mac OS computer. This pre-installed video editing software is really powerful, and so much good quality video editing can be done with it.
Many people will show you how to use iMovie for free online, but very few seem to talk about audio handling within iMovie, and more specifically, the right way to set your background music levels.
So what is the best volume level for background music?
Although there is no exact number to set background music audio levels in iMovie, most sound experts agree that background music should be between -18dBs and -20dBs lower than the main speech, dialogue or narration.
However, iMovie does not include a VU meter, which is a standard meter for reading decibel levels (dBs) for audio.
Therefore, how do you know what -20dBs is in iMovie?
The standard volume meter in iMovie seems to work with percentages (%) and not decibels (dB).
As someone who works professionally with audio, turning down audio by a percentage is not a standard way to work.
In the pro audio mixing world, we have general volume guides which are nearly all set to decibels (dB), or some equivalent volume level.
For example, I know that if I make my background music about -20dB lower than my main speech or dialogue in a project, I will be in a good starting place. From there I can adjust my audio levels depending on the overall audio mix of the video.
But it appears that iMovie does not have a dB meter, so how can you use these dB guides?
What to do if you have iMovie, and want to work with standard volume units such as decibels (dB)?
Let’s imagine that you are producing a video for YouTube and you want to get your audio levels and background music volume level sounding good.
Below is a table of guideline volume levels from my article, “How Loud Should Background Music Be?”, which dives into audio levels in greater depth.
|DESCRIPTION||AUDIO LEVEL RANGE||COMMENTS|
|Overall Audio Mix Level||-10dB to -20dB||This is your total audio mix level. |
Note: Never let your total audio mix level exceed 0dB.
|Main Narrator or Dialogue Levels||-6dB to -12dB||This is a good audio level range for your speech or dialogue audio. For Youtube, most YouTubers stay at -12dB max.|
|Background Music||-18dB to -20dB||This will vary but using the guide of 20dB lower than your speech audio is a good starting point|
|Sound Effects||-12dB to -18dB||Sound effects will vary greatly depending on the sound effect but ensure they do not impede or interfere with your main speech and dialogue.|
The above levels are a general guideline to help you get started, but since you cannot read dBs in iMovie, this good information is of no use for iMovie users.
For me personally, the solution is to install an external volume meter in iMovie.
I am not a big fan of having to do this, especially when my iMac cost me a couple of thousand pounds. However, below is a great video from Michael Kinney who shows you how to add pro audio meters to iMovie
With a good audiometer, you will know what level your audio is truly at and the audio level guides I mentioned previously will be useful for setting your audio levels.
Why does iMovie not have audio meters?
I have yet to understand why iMovie does not have standard audio meters but instead uses a “percentage” scale to adjust volume levels.
I have trawled through the manuals and apple support sites to see if the percentage scale somehow corresponds to a decibel (dB) volume scale but without any luck.
I even contacted apple support and I am still waiting for an answer.
My best guess is that to novice video makers, a volume meter could look a little intimidating, so a percentage scale seems more accessible and easier to read.
For example, “Jim turn down the volume by 15%” is probably easier to quantify for a general user as opposed to “Jim turn down the volume by 25dB”
In 2021, when novice video makers are using iMovie to build successful businesses on YouTube, I think it is fundamental that a good audiometer is made available in iMovie. It is a very standard and universal thing. The excellent software team at Apple could probably design one in an afternoon!
If you know why iMovie does not have a standard volume meter, please let me know in the comments as I am eager to find this out.
How to avoid audio distortion in iMovie?
The one thing you must always avoid when working with audio, be it in iMovie or any project, is audio distortion.
Audio distortion happens most commonly when audio is too loud or more specifically, exceeds 0dB. We call this clipping in the audio industry.
As mentioned, we do not have audio meters in iMovie, so how can you tell if your audio has exceeded 0dB or is clipping?
According to the apple support guide for iMovie, you will need to look at the audio waveforms to see if your audio is clipping or is distorted.
According to the iMovie support manual:
Make sure that the peak sections of the waveform don’t appear yellow, which indicates distortion, or red, which indicates clipping (severe distortion). If you see either red or yellow in your audio waveform, lower the volume until the entire waveform is green. If only part of the waveform is red or yellow and the rest is green, you can adjust the volume of that part of the waveform.
If waveforms don’t appear in the timeline, click the Settings button in the upper-right corner of the timeline and select the Show Waveforms checkbox.
Where can I download free background music for iMovie?
While you are here, if you are looking for free background music for iMovie, be sure to check out my free music library.
Below is a link to my free royalty free music collection where you can download free background music for iMovie. If you have any questions about how you can use this free music, please just get in touch.
To learn more about this free music for your iMovie projects, here is a detailed article about free music in iMovie