# Creating loopback for internal laptop soundcard



## murphy11 (Mar 1, 2008)

Hi all,

Dumb question but I can't figure out how to create a loopback connection on a Dell or Lenovo laptop with internal soundcards. Is some wiring connection needed? 

I recently bought a UMM-6 USB mike and downloaded latest beta REW which I think is compatible with USB mikes. Really looking forward to getting a true measurement to see what is going on in my room.

Mark


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## Phillips (Aug 12, 2011)

Hi good news do not do a laptop internal soundcard calibration, just import the mic calibration file and for calibration wise that's all that is needed. 

Where did you get the UMM-6?

Does it have on top / first line of the mics calibration file something like SENS Factor, if so that is for SPL calibration.


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## murphy11 (Mar 1, 2008)

Thanks! I was really struggling and have gotten a variety of feedback which has me confused (which is easy to do  ) 

I bought the UMM-6 USB from Parts Express and I've downloaded the calibration file from their site which corresponds to the serial number label on my mike. 

Part of my problem might have been that I was using REW 5.0 and not the latest beta version which is compatible with the UMM-6 USB. I did get REW 5.0 base version (2011) to recognize the mike once but it was very random. Good news is that REW 5.0 beta did automatically recognize the mike and asked for the calibration file which I selected. It seems like the beta version is more promising.

One problem I had been having is the sound levels produce an error saying measurement volume was too low (or something like that from memory) I thought maybe the soundcard was not calibrated properly but I will try again tomorrow the whole process using REW beta and see if I continue to have the same problem.

Thanks again!


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## murphy11 (Mar 1, 2008)

I had 2 problems that are resolved but now that I can measure I have a new one (that I may create a new thread for seeking advice)

The two problems that are now fixed are:

1) I was running REW 5.0 with UMM6 USB mike and have downloaded beta REW v17 which autorecognizes the mike and calibration file. I feel more confident that REW are mike are playing nice together now.

2) My system had muted the mike\recording device whch caused the low volume error\warning. Unmuting the mike solved the problem - imagine that


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## murphy11 (Mar 1, 2008)

I use ONIX Strata mini speakers connected to Lenovo laptop/ONIX A60 integrated amp. During measurement of both left and right speakers, both show huge rolloff after 4K.

I troubleshoot software for a living and haven't totally tried everything I can think of, but if anyone has ideas on how to root cause the problem I would appreciate the help!


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## murphy11 (Mar 1, 2008)

I might have blown tweeters according to the designer of the speaker. Working through the issue on another forum so no help needed until I figure out whether the speakers are the problem.


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## Phillips (Aug 12, 2011)

Maybe try one at a time to see if both of them are blown, turn down volume when measuring.


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## davesspeed (Aug 8, 2013)

The calibration file takes care of the calibration of the usb mike, but you still need to loop back the sound cards output back into its input and use the REW calibration wizard to check the accuracy of the signal you are sending out to your amp. After switching over to a toslink cable to send the signal sweep to my amp. I did a loopback and it checked out perfect. When I reran a sweep on my system, it is now different then the sweeps I was getting using my headphone jack output, which I did not have the cables to do a calibration on. The top end is about 10 db flatter, and the 45 Hz peak I have in my room is much smaller. I am now using less compensation for it, and different phase settings as well. Now that I am sending out an accurate signal for the usb mic to record. My adjustments to compensate, sounds much better. I was kind of chasing my tail for a while.

Do the highs really sound as bad as the readings suggest? You might be seeing something that is a software setup glitch that is not really there.


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