Headphone out on Macbook pro okay?

Robert Johansson

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Hello,

Sorry if this question already been posted.
Is the headphone out on a Macbook pro (late 2015) okay to use for taking measurements with REW?
I mean the frequency response of the 3,5mm output, is it straight from say 10Hz-20kHz or do i need an external sound card if i want correct mesurements??


Best regards,

Robert
 
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You need a proper, calibrated measurement microphone. Almost everyone uses a UMIK USB, costs about $100. You cannot use the built-in microphone for reliable measurements. No need for any output - REW runs on the MacBook. Does that answer your question?

[Edit: see post 6 below for my correct answer to OP]
 
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I'm not clear on what you're trying to do. If you want to use the headphone output of a MBP as a source for measuring the sound of an external system, it might be good enough. If you suspect it's not sufficient for whatever reason, you could try one of those USB dongle DACs (like an AudioQuest Dragonfly, but there's a bunch of them out there now), which should be fine.

This is all for objective measurements. Subjectively, the MBP sounds pretty bad.
 
I'm not clear on what you're trying to do. If you want to use the headphone output of a MBP as a source for measuring the sound of an external system, it might be good enough. If you suspect it's not sufficient for whatever reason, you could try one of those USB dongle DACs (like an AudioQuest Dragonfly, but there's a bunch of them out there now), which should be fine.

This is all for objective measurements. Subjectively, the MBP sounds pretty bad.
Here's a measurement: Audibly very close to transparent - you'd need trained ears and the lowest-possible distortion headphones to pick out any issue v. perfection. https://audiosciencereview.com/foru...dio-output-of-a-macbook-pro.18276/post-596549 Of course, the power and impedance-matching with the headphone would be critical. But as an output to an amp/preamp you'd be just fine.

Here's some other data to consider; Archimago says it's audible and he's a very credible source, IMO: https://archimago.blogspot.com/2015/05/measurements-usb-hubs-and-8khz-phy.html
 
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Hello,

Thanks for your answers, my question was if the output (3,5mm) is good enough for taking measurements in REW. (SWEEPS)
I will use a calibrated mic, the question was not about the mic, it was about the output and the frequency response of the output on the Macbook Pro 2015. I want to know if the headphone out (3,5mm) has a frequency response that is good enough/straight (10Hz-20k)(20Hz-20k??) or if i need a separate sound card to be able to get correct levels through out the whole spectrum when i measure the response of my system with REW.
I will not use the computer when i listen to music, only for taking measurements with REW.
Can i just use a cable (3,5mm to RCA) straight from my Macbook to my amplifier or do i need a separate sound card? I mean what if the output on the Macbook is -10db already at 40Hz? So basically i want to know the frequency response of my computers output.

Best regards,

Robert Johansson
 
Hello,

Thanks for your answers, my question was if the output (3,5mm) is good enough for taking measurements in REW. (SWEEPS)
I will use a calibrated mic, the question was not about the mic, it was about the output and the frequency response of the output on the Macbook Pro 2015. I want to know if the headphone out (3,5mm) has a frequency response that is good enough/straight (10Hz-20k)(20Hz-20k??) or if i need a separate sound card to be able to get correct levels through out the whole spectrum when i measure the response of my system with REW.
I will not use the computer when i listen to music, only for taking measurements with REW.
Can i just use a cable (3,5mm to RCA) straight from my Macbook to my amplifier or do i need a separate sound card? I mean what if the output on the Macbook is -10db already at 40Hz? So basically i want to know the frequency response of my computers output.

Best regards,

Robert Johansson
I understand what you mean now: You want to send the signal generated by REW to your amplifier, right? The answer is: Yes, it's fine. The audio system on the MacBook is perfectly fine and has flat FR. OTOH, It would be best if you output from USB to a good DAC (no need to spend more than $150 for an outstanding DAC. Check out audiosciencereview.com for a list of tested DACs).

There is another alternative: You can save the REW sweep as a file and play that through your regular source. There's a setting in REW that is triggered by that sweep and then REW measures the output from your speakers. Either method will be perfectly fine for measuring your room for EQ purposes.
 
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I understand what you mean now: You want to send the signal generated by REW to your amplifier, right? The answer is: Yes, it's fine. The audio system on the MacBook is perfectly fine and has flat FR. OTOH, It would be best if you output from USB to a good DAC (no need to spend more than $150 for an outstanding DAC (check out audiosciencereivew.com for a list of tested DACs).

There is another alternative: You can save the REW sweep as a file and play that through your regular source. There's a setting in REW that is triggered by that sweep and then REW measures the output from your speakers. Either method will be perfectly fine for measuring your room for EQ purposes.

Thank you :-)
 
There is another alternative: You can save the REW sweep as a file and play that through your regular source. There's a setting in REW that is triggered by that sweep and then REW measures the output from your speakers. Either method will be perfectly fine for measuring your room for EQ purposes.

Thanks for calling this out. The key, I've found is to do one channel at a time and save a timing reference with the channel you're measuring (Left for Left, Right for Right). You could even burn the sweeps to a CD-R and use an old CD player as a source if you wish. I use this approach all of the time. Works great, as long as REW's measurement parameters exactly match those used to generate the sweeps and it's set to use an acoustic timing reference. Great tip.
 
From Apple: "Headphone: You can use this port as a combination headphone and line-out port. Connect headphones (with or without a built-in microphone), self-powered speakers, or other audio equipment using a standard audio cable with a 3.5 mm metal plug.

Some Macs also support optical digital audio output via the headphone audio port. Use a Toslink cable with a Toslink miniplug adapter or a fiber-optic cable with a 3.5 mm plastic or nylon optical plug. To check if optical digital audio is available on your Mac, see the Apple Support article Play high sample rate digital audio on Mac computers."
 
If it helps I’ve been using a mini TOS-link to TOS-link cable with my MacBook Pro 2013 for about 4 years with REW and it produces the same results as my MSI Gaming laptop via HDMI.
 
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