Review changes:

- Fix `if (!external)` styling
- Remove unecessary ConnectAsync overload

src/Discord.Net.Core/Entities/Channels/IAudioChannel.cs

@@ -7,9 +7,6 @@ namespace Discord
     public interface IAudioChannel : IChannel
     {
         /// <summary> Connects to this audio channel. </summary>
-        Task<IAudioClient> ConnectAsync(Action<IAudioClient> configAction = null);
-
-        /// <summary> Connects to this audio channel but can specify if client is handled externally. </summary>
         Task<IAudioClient> ConnectAsync(Action<IAudioClient> configAction = null, bool external = false);
 
         /// <summary> Disconnects from this audio channel. </summary>

src/Discord.Net.Rest/Entities/Channels/RestGroupChannel.cs

@@ -143,7 +143,6 @@ namespace Discord.Rest
             => EnterTypingState(options);
 
         //IAudioChannel
-        Task<IAudioClient> IAudioChannel.ConnectAsync(Action<IAudioClient> configAction) { throw new NotSupportedException(); }
         Task<IAudioClient> IAudioChannel.ConnectAsync(Action<IAudioClient> configAction, bool external) { throw new NotSupportedException(); }
         Task IAudioChannel.DisconnectAsync() { throw new NotSupportedException(); }
 

src/Discord.Net.Rest/Entities/Channels/RestVoiceChannel.cs

@@ -41,7 +41,6 @@ namespace Discord.Rest
         private string DebuggerDisplay => $"{Name} ({Id}, Voice)";
 
         //IAudioChannel
-        Task<IAudioClient> IAudioChannel.ConnectAsync(Action<IAudioClient> configAction) { throw new NotSupportedException(); }
         Task<IAudioClient> IAudioChannel.ConnectAsync(Action<IAudioClient> configAction, bool external) { throw new NotSupportedException(); }
         Task IAudioChannel.DisconnectAsync() { throw new NotSupportedException(); }
 

src/Discord.Net.WebSocket/Entities/Channels/SocketGroupChannel.cs

@@ -206,7 +206,6 @@ namespace Discord.WebSocket
             => EnterTypingState(options);
 
         //IAudioChannel
-        Task<IAudioClient> IAudioChannel.ConnectAsync(Action<IAudioClient> configAction) { throw new NotSupportedException(); }
         Task<IAudioClient> IAudioChannel.ConnectAsync(Action<IAudioClient> configAction, bool external) { throw new NotSupportedException(); }
         Task IAudioChannel.DisconnectAsync() { throw new NotSupportedException(); }
 

src/Discord.Net.WebSocket/Entities/Guilds/SocketGuild.cs

@@ -518,37 +518,38 @@ namespace Discord.WebSocket
                 promise = new TaskCompletionSource<AudioClient>();
                 _audioConnectPromise = promise;
 
-                if (!external)
+                if (external)
                 {
-                    if (_audioClient == null)
+                    var _ = promise.TrySetResultAsync(null);
+                    await Discord.ApiClient.SendVoiceStateUpdateAsync(Id, channelId, selfDeaf, selfMute).ConfigureAwait(false);
+                    return null;
+                }
+
+                if (_audioClient == null)
+                {
+                    var audioClient = new AudioClient(this, Discord.GetAudioId(), channelId);
+                    audioClient.Disconnected += async ex =>
                     {
-                        var audioClient = new AudioClient(this, Discord.GetAudioId(), channelId);
-                        audioClient.Disconnected += async ex =>
-                        {
-                            if (!promise.Task.IsCompleted)
-                            {
-                                try
-                                { audioClient.Dispose(); }
-                                catch { }
-                                _audioClient = null;
-                                if (ex != null)
-                                    await promise.TrySetExceptionAsync(ex);
-                                else
-                                    await promise.TrySetCanceledAsync();
-                                return;
-                            }
-                        };
-                        audioClient.Connected += () =>
+                        if (!promise.Task.IsCompleted)
                         {
-                            var _ = promise.TrySetResultAsync(_audioClient);
-                            return Task.Delay(0);
-                        };
-                        configAction?.Invoke(audioClient);
-                        _audioClient = audioClient;
-                    }
-                } else
-                {
-                    var _ = promise.TrySetResultAsync(null);
+                            try
+                            { audioClient.Dispose(); }
+                            catch { }
+                            _audioClient = null;
+                            if (ex != null)
+                                await promise.TrySetExceptionAsync(ex);
+                            else
+                                await promise.TrySetCanceledAsync();
+                            return;
+                        }
+                    };
+                    audioClient.Connected += () =>
+                    {
+                        var _ = promise.TrySetResultAsync(_audioClient);
+                        return Task.Delay(0);
+                    };
+                    configAction?.Invoke(audioClient);
+                    _audioClient = audioClient;
                 }
 
                 await Discord.ApiClient.SendVoiceStateUpdateAsync(Id, channelId, selfDeaf, selfMute).ConfigureAwait(false);