Can Headphone Ouput (MacBook Pro) hookup to audio monitors?

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Can Headphone Ouput (MacBook Pro) hookup to audio monitors?

Hi,
I have a MacBook Pro (not sure of the model, but it's not the latest model, rather the second last model released, purchased in Aug 2008). I would like to hook up a set of Mackie MR5 audio monitors to it, for video editing purposes. Can I simply run a cable from the headphone jack out from the MacBook Pro and into the audio monitors? I don't know much about this stuff, and was wondering if it was necessary to have a "Line Out" for proper hook-up of audio monitors. What I'm wondering is this: Will the 'powered' headphone audio out jack be too much for the 'line in' connectors on the MR5 speakers? Will it damage the speakers?
Thanks very much for your expertise!
Vic

MacBook Pro, Final Cut Express

Posted on Jun 24, 2010 6:24 PM

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Answer 1

Jun 24, 2010 7:39 PM in response to Vixter101

The Mackie MR5 input impedance requirements are 10 kilo-ohms for unbalanced signals and 20 kilo-ohms for balanced signals. Headphone outputs are unbalanced, but I don't know what the impedance is for a MacBook headphone output. If the impedance doesn't match, you'll need to use a mixer or something like the Griffin iMic to get the impedance level right for input to the speakers.

-DH

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Answer 2

Vixter101 Author

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Jun 24, 2010 9:09 PM in response to David Harbsmeier

Thank you, David. So much for a simple, black & white answer. I wish I knew more about tech specs, and impedances, and digital and analog, and all the other stuff. It's all such that it's more about technical and less about art these days. One definitely needs to team up with a technical guru. Oh well! Do you know if the M-Audio bx5 monitors work better with the headphone output from a laptop?
Thanks again, David.

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Answer 3

Jun 25, 2010 4:58 AM in response to Vixter101

Clearly David knows his stuff, but I will add that I have done similar things with other devices, carefully tweaking the volume on the computer and the gain.

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Answer 4

MartinR

Level 7

24,378 points

Jun 25, 2010 6:55 AM in response to Vixter101

I regularly use the MBP headphone out to connect to headphones as well as line-in inputs. Works fine both ways. The Mac audio out circuitry appears to be self-adjusting for impedance, and I have never encountered any issues connecting to either type of input. (If the impedence is mismatched you would notice it in the audio as muffling of the higher frequencies or overall deadness in the sound.)

You may need to adjust the gain, that's all. I'd suggest using the RCA/unbalanced inputs on your MR5's.

Ditto for all the Macs I have ever owned or managed.

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Answer 5

Vixter101 Author

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Jun 30, 2010 3:05 AM in response to MartinR

I've hooked up the MR5s two different ways and am getting the same problem: static noise. It's not the "constant hum" that is common with a lot of cheap computer speakers. It's more like the sporadic static sound you'd hear if you were hooking up speakers... touching the wires to the contacts on the speaker. And, it's not consistently steady, either; it's intermittent (sometimes soft, then gets louder for a second or two, then soft again, then another crackle). And this happens when there should be NO sound at all coming out of the speakers (i.e. with nothing playing on the computer, and even the volume turned all the way down). Like a "dirty electronics" noise. But, the wires are new (and I even tried a couple of different wires/cables. I even hear interference from my computer mouse (as I scroll).
I know nothing about audio, and I'm very disappointed. I just purchased the monitors so my video work would sound better. And, from what I've heard, these are supposed to be good, clean speakers. Shouldn't there be virtual silence when no sound is being fed into the system? Anyone know what I could try? Could there be a problem with the output from the Mac? (though, when listening with the headphones, I don't hear the static noise. Any advice would be immensely appreciated.
Thanks,
Vic

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Answer 6

MartinR

Level 7

24,378 points

Jun 30, 2010 9:43 AM in response to Vixter101

Often happens when the audio plug is not fully seated or has some corrosion (which often looks like dull metal, it doesn't have to be greenish to be corroded). Try pulling & reinserting the plugs (of course with the audio muted and/or your Mac and MR5's shut down). It happens to me sometimes too and reseating the plugs always clears it.

Then, too, it's possible the cable you are using is bad or there is some problem with the MR5's even if they're new. The fact that there's no static when you use your headphones is a good clue that the problem is not in your Mac.

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