# ART Dual pre - how important to calibrate?



## PTAaron (Feb 16, 2012)

Hey guys - I picked up some new toys last week and was planning to play this weekend, but I forgot to order a "loop back" cable for the ART dual pre USB that I picked up. 
I saw it mentioned that for the Tascam unit you could get away without a loopback and assuming it had a flat response - any chance the same is true for the ART unit? 
I checked Radio Shack already with no luck finding the cable I need (male 1/4" to male XLR) - so I will be ordering one from monoprice anyway... but will I get useful info if I start playing around without it?


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## Digital_Chris (Apr 7, 2011)

The XLR input on the ART also accepts a 1/4" connector so you should be able to use 1/4" to 1/4" TRS cable for the loop back connection


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## PTAaron (Feb 16, 2012)

Digital_Chris said:


> The XLR input on the ART also accepts a 1/4" connector so you should be able to use 1/4" to 1/4" TRS cable for the loop back connection


Oh really?? I didn't notice that! 
I happened to drive by a Guitar Center - they had the other cable, so I'm good to go.


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## Digital_Chris (Apr 7, 2011)




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## PTAaron (Feb 16, 2012)

Just to be sure I "get it" - I can just run the right (or left) channel 1/4" TRS output to the same channel input on the front and the other output (or headphone monitor output) over to my AVR and things should work, right? 
I am over thinking it and it seems like it should be more complex than that.


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## fotto (Jan 17, 2010)

If I'm understanding your question properly, to calibrate your Art. all you need is one loopback connected from R out to R in on the Art (Right channel just used for example). Once you run REW cal routine and get a cal file, you no longer need that loopback. For measurements then just take your Art R out to your AVR.
You can do loopback on the left channel out to in if you want to use loopback as timing ref for ETC measurements or other reasons.


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## PTAaron (Feb 16, 2012)

fotto said:


> If I'm understanding your question properly, to calibrate your Art. all you need is one loopback connected from R out to R in on the Art (Right channel just used for example). Once you run REW cal routine and get a cal file, you no longer need that loopback. For measurements then just take your Art R out to your AVR.
> You can do loopback on the left channel out to in if you want to use loopback as timing ref for ETC measurements or other reasons.


You got it, that is exactly what I was asking. I thought I was over thinking it 
Thank you for the reply!


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## DexPro (May 16, 2012)

Hey all,
I'm new to the forum. I just picked up an Art Mobile pre as well and I'm running REW on os10. I can't get the soundcard to show the art as an option but I can get a signal through it if I change the unit over in system prefs of os 10. When I try to do the loop back I get a low signal and if i try to turn it up it goes straight to clip. Not sure what to do any ideas?

Thanks,

James


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## Wull (Apr 7, 2010)

DexPro said:


> Hey all,
> I'm new to the forum. I just picked up an Art Mobile pre as well and I'm running REW on os10. I can't get the soundcard to show the art as an option but I can get a signal through it if I change the unit over in system prefs of os 10. When I try to do the loop back I get a low signal and if i try to turn it up it goes straight to clip. Not sure what to do any ideas?
> 
> Thanks,
> ...


If using Windows 7, In your PC's 'Recording devices' / Advanced, set to 2 channel, 16bit, 44100 Hz, and try setting the input level down to 2 or 3, then use the Art dual gain knob to adjust the input.

This worked for me...


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## Cali (Feb 24, 2011)

Thank goodness for this thread. The ART manual mentioned 1/4" in but I didnt see it....finally decided to just push and in it went.


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## ahhh (Jul 16, 2012)

Can you share your calibration file?


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## Wull (Apr 7, 2010)

ahhh said:


> Can you share your calibration file?



Not sure how accurate it will be for you using someone else's?

If you PM me your email address I can forward you mine.


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## Barleywater (Dec 11, 2011)

DexPro's situation in post #8 is exactly why it is very important to perform your own loopback measurement. DexPro clearly has a case of input monitoring feedback.

Using a calibration that includes the feedback may look flat, but it means it will be present when using microphone to make room measurements, and the results are incorrect. They will have imbedded upon them artificial comb filtering that looks like this:



The first big hump will be interpreted as lots of bass. The rest of the ripples will tend to be interpreted as comb filtering, leading to incorrect conclusions about room reflections, and if using REW EQ, cause is it to create bad filters.

Most sound cards are good enough to use without calibration, unless trying to get really good results <20Hz, but results will still be bad without a calibration when input monitoring is occurring.

Hardware and software settings must be found to eliminate the problem.

Do the loopback, figure out how your system works, and gain confidence in your results.

Andrew


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