How can I play the sound from the audio in through my speakers?

Question

I have got a Macbook Pro 15" that has both an audio in and out port. Now I would like to play the sound from an external device through the speakers of my Mac.

How can I do that? I tried to just plug in the 3.5mm cable from my external device into the audio in port but I simply cannot make my Mac play the sound. However, in System Preferences -> Sound -> Input I can see that the Mac is receiving the signals.

What can I do?

score 5 · Answer 1 · answered Nov 28 '13 at 14:22

5

If you don't have Garageband installed you can also use Quicktime.

Open Quicktime
Go to File -> New Audio Recording. You will see the following screen:
Click on the little triangle on the right and choose Built-in Input: Line in as shown in the screenshot.
Slide the volume under the record button up until you have the desired loudness.

answered Nov 28 '13 at 14:22

Saaru Lindestøkke

5,821

9

For me this imposes about 300ms input delay. Is there a way to adjust that delay (perhaps by means of some ´defaults´ setting for QuickTime)? – Henrik Feb 17 '17 at 14:59
Don't think you can configure QuickTime, it sounds like a latency problem What device are you connecting? – Saaru Lindestøkke Feb 17 '17 at 20:50
1

the delay is bad – Chaim Eliyah May 13 '18 at 01:46
I can confirm this adds a significant delay. The on-screen meter responds to sounds almost immediately, but I don't hear them until several hundred ms later. The latency seems to be added by Quicktime. – Josh Aug 17 '20 at 22:52

score 3 · Answer 2 · answered Nov 28 '13 at 14:11

3

You can use GarageBand:

Create a new project and choose for example the voice template
Set Monitor to On
Optionally remove the effects from the Edit tab

answered Nov 28 '13 at 14:11

Lri

105,117

I also found delay using this method :( – Pablo Guerrero Apr 07 '20 at 02:08
Any tips on preventing feedback when used for Karaoke? – Gabriel Fair Feb 14 '24 at 16:40

score 2 · Answer 3 · answered Sep 20 '18 at 14:51

2

You can use the SoundSource app from Rogue Amoeba to set your sound on "Play-Thru". Or you can do it in their free Line-In app, which has been retired but can still be downloaded.

answered Sep 20 '18 at 14:51

Earl Zubkoff

21

2

The free app: LineIn worked for me, up until I upgraded OSX to 10.14 mojave- now it doesn't work. – user313267 Dec 08 '18 at 01:15

Philippe Côté · Answer 4 · 2021-03-12T23:06:34.280

2

A bit late to the party but I’ve stumbled on a solution on another StackOverflow website that led me here: http://jsfiddle.net/jib1/7ejwaxkc

It works wonderfully as an audio passthrough. Took me ages to find... phew!

Enjoy!

EDIT: Found out the solution isn’t perfect: it’s mono. :(

edited Mar 12 '21 at 23:06

answered Mar 12 '21 at 22:05

Philippe Côté

21

1

While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes. – grg Mar 12 '21 at 22:18
@grg Ah yes, good point. Thanks! (I’m a total newb, as you may have found, haha... ) – Philippe Côté Mar 12 '21 at 23:08

How can I play the sound from the audio in through my speakers?

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