How to play an audio file after another finishes

You need only one AudioSource. Add this script and assign AudioClips.

     using UnityEngine;
     using System.Collections;
 
     [RequireComponent(typeof(AudioSource))]
     public class ExampleClass : MonoBehaviour
     {
         public AudioClip engineStartClip;
         public AudioClip engineLoopClip;
         void Start()
         {
             GetComponent<AudioSource> ().loop = true;
             StartCoroutine(playEngineSound());
         }
 
         IEnumerator playEngineSound()
         {
             audio.clip = engineStartClip;
             audio.Play();
             yield return new WaitForSeconds(audio.clip.length);
             audio.clip = engineLoopClip;
             audio.Play();
         }
     }
 
 
 
 
 

@HonoraryBob I tried what you guys told but it still have a pause/delay. But this post helped me to find a solution!

This worked perfectly for me:

 musicIntro.Play ();
 musicLoop.PlayDelayed(musicIntro.clip.length);

Hope it helps someone in 2018+ :D

 using UnityEngine;
 using System.Collections;
 [RequireComponent(typeof(AudioSource))]
 public class LoopBGM : MonoBehaviour
 {
     public AudioClip StartClip;
     public AudioClip LoopClip;
 
     void Start()
     {
         StartCoroutine(playSound());
     }
 
     IEnumerator playSound()
     {
         GetComponent<AudioSource>().clip = StartClip;
         GetComponent<AudioSource>().Play();
         yield return new WaitForSeconds(StartClip.length);
         GetComponent<AudioSource>().clip = LoopClip;
         GetComponent<AudioSource>().Play();
         GetComponent<AudioSource>().loop = true;
     }
 }

The problem is that switching the audioclip adds a small delay to the processing. It is also a good idea to give unity some time to preload everything.

add 2 audiosources. Wait for the first one to finish and play the second one.

 using UnityEngine;
 using System.Collections;
 
 [RequireComponent(typeof(AudioSource))]
 public class QueueAudioClip: MonoBehaviour
 {
     public AudioSource audioSourceIntro;
     public AudioSource audioSourceLoop;
     private bool startedLoop;
 
     void FixedUpdate()
     {
         if (!audioSourceIntro.isPlaying && !startedLoop)
         {
             audioSourceLoop.Play();
             Debug.Log("Done playing");
             startedLoop = true;
         }
     }
 }
 

you should do something like this

 AudioClip otherClip; 
 bool playNow = false;
 
 yield WaitForSeconds (audio.clip.length); 
 playNow = true;
 
 void Update () {
 
 if(playNow) { 
 // Assign the other clip  
 audio.clip = otherClip; 
 audio.Play(); 
 playNow = false; 
 }