# First REW laptop setup...why CANT I use the mic input?



## jlird808 (Nov 2, 2010)

Is there a reason? Is the quality just too bad? 

From the cabling/setup sticky:
*LAPTOP Note:
If your laptop is limited to a mic-in port with no line-in, then you'll require an external USB soundcard.*

I wanted to plug in my RS SPL meter/mic and do mobile measurements. I didnt really feel like getting an interface though as I can measure at my desktop perfectly fine...this was just a side project.

Thanks!


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## Wayne A. Pflughaupt (Apr 13, 2006)

A lot of laptops these days have a mic input that can be switched to line input. If yours can do that, then you can use the Radio Shack meter for measurement. Not sure how you’re going to accomplish a soundcard calibration though – hopefully it will work to loop the headphone output back to the input.

Regards,
Wayne


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## jlird808 (Nov 2, 2010)

Wayne A. Pflughaupt said:


> A lot of laptops these days have a mic input that can be switched to line input. If yours can do that, then you can use the Radio Shack meter for measurement. Not sure how you’re going to accomplish a soundcard calibration though – hopefully it will work to loop the headphone output back to the input.
> 
> Regards,
> Wayne


Hmmm....my laptop does have some controls via some Realtek HD (I think thats what its called...not in front of it right now) interface. I can adjust the mic volume, add effects (which I wouldn't), etc. Not sure if it would switch to a line input but it does get loud. In fact, REW detects the RS meter mic as TOO LOUD during level checks so I have to crank the mic volume on the Realtek controls WAY down.

Regarding the soundcard calibration, I would say it came out fine actually. I ran a short stereo mini-jack cable from the headphone out to the mic in. I cant post a pic here at work but it looked like a standard soundcard cal file with dips at both ends and pretty much flat in the middle.

I ran the RTA and was definitely getting a signal. I used the generic RS cal file and clicked "C weighted meter". While it didn't look pretty, it was definitely responding to audio. There was a pretty wide and subtle dip across the entire mid-range. I hear the RS shack meter is only good for analyzing up to 3khz anyways right?

Thanks for the help...again this is just a side project but I'd like to see this work!! :nerd::bigsmile:


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## jlird808 (Nov 2, 2010)

Any other input? If i can get enuff gain from the laptop mic input, is that ok?


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## Wayne A. Pflughaupt (Apr 13, 2006)

Just fine for a “side project,” I’m sure. Be interested to see what your calibration file looks like, though. I expect that the mic input will have rather poor frequency response.

Regards,
Wayne


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## pc_light (Feb 22, 2012)

Can't say for sure what may be happening with your laptop but I can share what I've found with mine to date , I'm actually in the process of acquiring an audio interface/external sound card now because I wasn't able to get my setup with laptop working.

Ironically the gain on my HP6910p appears to be too high, I had to turn all mic boosts off, mic enhancements off, and I had to gain down to about 8% before I could even try to calibrate the sound card with loop cord. That should have been my first clue that it wouldn't work.

My attemptbroke down when I connected the RS SPL, it would peg the needle because the signal was too strong. I suspect it's electronic noise or feedback between the laptop and the SPL. 

I can share other things I tried to no avail - 
- turning off laptop wireless, 
- turning off all applications, 
- running on either battery and AC
- running when fan was running and when it wasn't

I have confirmed that the SPL and cables used are all fine because they all calibrate and work with my desktop in the other room. But like yourself, I'm trying to calibrate the subwoofer and speakers in the family room using laptop.

Just thougt I'd share.


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## jlird808 (Nov 2, 2010)

Hey I'm back on this project lol...

Would these work to power my EMM6 via my laptop?

http://elitecoremusic.com/usb-microphone-adapter-w-phantom-power/

http://www.bhphotovideo.com/c/produc...Mic_Mate_.html

I dont see anyone using em here. But this way I could use my omni instead of the RS meter.

Thanks!


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## Wayne A. Pflughaupt (Apr 13, 2006)

Hey jlird,

Sorry, but those won’t work. You need a mic pre-amp that has phantom power.

REW Cabling and Connection Basics

Regards,
Wayne


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## pc_light (Feb 22, 2012)

Wayne A. Pflughaupt said:


> Hey jlird,
> 
> Sorry, but those won’t work. You need a mic pre-amp that has phantom power.
> 
> ...


After looking at the image jlird referenced, I was wondering where the power input would be since there was a button indicating "48v Phantom Power".

Now it makes sense, it's probably a toggle for when the device is fed into a pre-amp on the way to the computer.


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## jlird808 (Nov 2, 2010)

Lol this one says it has a preamp inside:

http://www.bhphotovideo.com/c/product/522285-REG/MXL_MIC_MATE_USB_Mic_Mate_.html

Wouldnt it allow an omni condenser to connect to USB, something similar to this?:

http://www.bhphotovideo.com/c/product/522285-REG/MXL_MIC_MATE_USB_Mic_Mate_.html

...except this sE is not omni. As long as my driver detects the input as a mic it should be ok right?

Regardless, I kinda ruled these out anyways bcz, in another thread here, ppl were saying I want a dual channel interface so as to help with the "loopback hardware propagation delay compensation" lol. Those were SAC's words so I should probably just shut up and listen LOL.


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## pc_light (Feb 22, 2012)

jlird808,

Sharing another thought with you.

I'm staying low budget because I'm really just using REWS to help setup subw and perhaps learn a little more about the FR of my system/room. Like you laptop, my Realtek HD chip seems to imply it has the capability to take line-in input somewhere, just not at the mic input port.

SO - I decided to pickup a used docking station for my notebook which turns out to have a audio line-in! So instead of $30 for a budget external USB card, I only have to spend $12 on a used docking station.

I'll let 'ya know how it turns out.


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## jlird808 (Nov 2, 2010)

HMmm....can I ask what kinda docking station ur talking about? Like an iPod docking station?


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## pc_light (Feb 22, 2012)

Some laptops have docking stations as an option. The laptop drops into it for charging and other purposes. It's loaded with extra DVI video ports, USB ports, mouse/keyboard, etc. and in this case, an audio line-in port!

I'm hoping that once the laptop is connected to the docking station the Realtek chip can be configured to recognize the line-in.

Try Googling for your laptop model and the term "docking station". New the option would have cost ~$100 but since my laptop older now, used ones are on sale for $12-20 on eBay (here's an example in my case).


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## jlird808 (Nov 2, 2010)

Here's my calibration files for my laptop Realtek HD and RS mic/meter.

I just plugged a short 1/8" minijack cable from the headphone output to the mic input. Like PC Light was saying, I had to go into the Realtek software interface and REALLY turn down the mic's gain.









To be honest I DID have to adjust the soundcard in/out preferences a few times to get it to work finally. I was getting pretty freaky looking cal files at first LOL. I don't wanna make any more adjustments... this is how I have the prefs setup though.









I'll start moving forward tomorrow...does this look pretty normal though with these settings though?

THANKS!

**EDIT: I wont be doing sweeps from this laptop. I'd have to plug the laptop into a receiver and recalibrate I think. Basically this is just to run an RTA at my friends place and in my car....at both places I'll be playing a looping pink PN.


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