# Steinberg UR22 REW problem



## FrankySaxy (Jan 8, 2014)

I bought myself a Steinberg UR22 2 in 2 out 24/192 soundcard to use with REW outside my homestudio where I got it working on a MAC with the studio's Focusrite Scarlett 18i20.

I first installed the latest beta release of REW on a Windows 7 laptop. I started using the Steinberg UR22 with Behringer ECM8000 mic and setup the loopback.
when calibrating the UR22 I always get this error message: Excessive variation in measurement.









I searched the forum to find more and saw someone with similar error message who reverted back to original official REW 5.0 release. I did the same and there calibration seems to work, at least I don't get the error message (maybe it's not even generated when there is a problem?!).

I attach a jpg from a measurements' image of only the MIC Cal and Soundcard Cal graph lines.









Can somebody tell me if and what I'm doing wrong? I thought the Soundcard cal would be a more smooth line.

Next can you tell me why I encounter the error when using the latest beta release?

Thanks for your help.


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## JohnM (Apr 11, 2006)

The UR-22 should work without problems, there's one sat on my desk I bought to check 192k operation. To make a loopback measurement on it connect one of the line outputs on the back panel to one of the mic/line inputs using a TR connector, make sure you tell REW which input you are using on the Soundcard preferences input channel selection (assuming you are using Java drivers) or select the correct channel if using ASIO. 

The plot you posted looks like a room measurement rather than a loopback, perhaps you had REW set up to listen to the input the ECM8000 is connected to instead of the input the loopback is connected to. The mic is not used for a loopback measurement.


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## FrankySaxy (Jan 8, 2014)

Thank you, John.

I already saw that you had the UR22 as well. One of the reasons I thought it was a good choice to get a working REW setup. And, a nice little device for other purposes as well.

I did the loopback. I connected the UR22 as follows:
Input 1: mic
Input 2: loopback from output 2
Output 1: with stereo 6.4 to stereo 3.5 adapter to stereo 3.5 to 2x RCA adapter to RCA cable to L/R pre-amp input.

Just as I done this several times before in the studio on Mac with Scarlett.

So, if I understand you correctly the mic should be disconnected while doing the soundcard calibration? I thought REW only measured the designated loopback channel in the settings. Would my mistake (connecting the mic) generate the error message?


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## JohnM (Apr 11, 2006)

Having the mic connected doesn't matter as long as the correct input is selected for REW, the soundcard cal trace you showed looks like a room measurement which suggests the mic input was selected when making it.

I'm a bit puzzled by your mention of a stereo connector on output1, those outputs are mono. I use a simple mono jack to RCA adaptor for them. What connectors are you using for the output 2 to input 2 connection?


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## FrankySaxy (Jan 8, 2014)

Thanks again for your reply, John.

With stereo connector I mean a Tip-Ring-Sleeve 6.4 male to 3.5 female adapter, from there to a TRS 3.5 mm male to dual RCA from which to the pre-amp's L & R. Just what I had laying around to make it work and that does. I get sweep signals from both speakers.

I was still puzzled by the measurements and also thought it was more a room response than a soundcard response.

Here's how I set it up:








This is when it goes wrong. I used Steinberg's ASIO driver. Connected the MIC to input 1, the loopback from output 2 to input 2 and the pre-amp to output 1.
I believe that's how I also did it in the preferences.

I then tried once with reversing input 1 to input 2 and input 2 to input 1 in the preference settings only, leaving the hardware loopback connections untouched and removing the mic from input 1, and then I get this measurement:









That looks like something that could be used, however I'm puzzled by how I got it. It seems wrong to me since in the setting it does state Timing Reference Input and Output. I guess this is meant by the loopback.

For my reference: Does the level at "In" mean the loopback signal and the "Ref in" the mic or the other way around?


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## JohnM (Apr 11, 2006)

"In" is what REW is measuring, so for a room measurement the mic should be selected there, but for a loopback measurement it should be the input the loopback is connected to.


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## FrankySaxy (Jan 8, 2014)

Thanks again, John.

OK, sorry that wasn't really clear. So, when I changed the connections in the settings it was similar to changing the leads on the interface and it turned out OK. I wasn't aware that only IN is used for measurements, I thought both were used when connected and the software took care of all. Seems I didn't read the manual good enough.


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## deepthought (Jun 5, 2013)

Hay, just a question. I've just bought a UR22 myself and did a feedback loop calibration as you have done. I got very close figures across the frequency range to those shown in your graph. I guess my question is, does it concern you that both these units (yours and mine) both have a response that is pretty much identical in their discrepancy from the manufacturer's specifications? The spec's on the unit all read something in the order of -0.5db between 20hz-20khz (from memory) so both our findings are well short of the mark. The other thing is that the unit is touted as having 192khz sampling capabilities. If I use the ASIO drivers and set the sampling rate to 192khz I get exactly the same frequency (limited) response. 
Since the DAC would not be the weak-point, I assume this is an issue with the Preamps.
Perhaps I'm missing something here? I am using a TRS to TRS cable so it is unbalanced in operation. Would that effect the preamp?
Does anyone have any thoughts on this? :huh:


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

deepthought said:


> The spec's on the unit all read something in the order of -0.5db between 20hz-20khz (from memory) so both our findings are well short of the mark.


 The sound card calibration graph in Post #5 shows response is down maybe 1 dB at 20 kHz, if that. Are you really concerned that it’s a .5 db out of spec?? :huh: Regardless, that's what calibration file is for, to correct that.

Regards, 
Wayne


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## deepthought (Jun 5, 2013)

Wayne,

Well it sounds petty when you put it that way and I know that the calibration file sorts this out. I am in no way pointing the finger at REW. I think it's a fantastic piece of software but my concern is this. Even if I specify a very high sampling rate, I am still only going to get the same -1db at 20khz from this piece of hardware. No matter what. In the bigger picture (outside of REW) shouldn't that be a cause or concern in a device that sells itself on its spec's and the quality of its preamps?:scratch:


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## FrankySaxy (Jan 8, 2014)

As the original poster of the graphs, I didn't look at the numbers. I just needed a good cal file for the UR22, which I didn't get because I (mistakenly) assumed that REW would measure both inputs, not only IN. Therefore I didn't get a good calibration at first.
Your question is entirely different since it is about the quality of the soundcard and since you believe (based upon company specs) that the soundcard is off by 0.5/1dB.
I can't really comment on that, because I don't know the specs and to me it looks very flat. If my speaker output in my room looked like that and with an even waterfall of say 200 - 300 msec, I would have the best reference room in the world.
It could be, as you said, have to do with the cabling, input versus output level, or any other external influence. To be sure and repeat a measurement done by manufacturers for their specs, I think you need to know exactly what the circumstances of the test setup were. So you need the same cables, the exact same gain, the same test software and audio signal, etc., etc.
And still, it will probably turn out like companies' specs of cars that always consume more fuel than listed.
Like I said, for me it's not important that it is off by a little, it looks extremely flat to me though. And I didn't try REW on the highest bitrates since that wasn't in the scope of my measurements. I bought this soundcard for the sole purpose of REW to begin with and have a very flat, high res, little soundcard that I can use for other purposes as well.
I did my room measurements and I now know for sure that it isn't the soundcard, the software or the speakers that cause the imperfections in sound. It's the room. A more expensive soundcard with even flatter and accurate cal file will not convince the wife and kid that I need to get rid of all their belongings to get a better listening room........

Sorry for the long post, I couldn't resist.....


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## deepthought (Jun 5, 2013)

Franky,

Well put! I guess I was just expressing my dismay that the unit seems to not comply to whatever spec's the manufacturer gives on it. I have never gotten the claimed fuel economy out of my car either so I suppose I should have come to grips with this phenomenon by now. For the purposes of using REW it will do exactly what is require as you state.


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## deepthought (Jun 5, 2013)

Hello again. Just one more question. I have been trying to do some serious testing with the UR22 / ECM8000 combination but I seem to be hitting a problem. The Steinberg website warns that some UR22 units will create low-freq rumble when supplying phantom power to condenser mics. My unit doesn't fit into the batches that are meant to be affected by the problem BUT, I was trying to do some tweeter measurements and I was getting a really strange response in REW. I repeated the measurements again with the midrange and the issue persisted. I then got the mic and stopped up the end with blu-tack, covered it is acoustic foam and bunged it in an airtight box. I put on RTA with no audio output so that all I should be getting is pretty much silence, minus the noise floor of the UR22 and perhaps cable noise. What I got was a nasty rise in noise that started at 4khz and then increased gradually to a peak at 20hz. This is a 38db rise. Everything above the 4khz point looks great, i.e. flat with some very high frequency artefacts from the DAC. I also disconnected the Mic and with phantom power on the rise was still there. Switch phantom power off and the rise is still present but is now buried very low in dB.
I did this at work so I don't have access to the measurement I did but based on this, would you think that I have a dud unit? I can't make any sort of accurate measurement from this unit from what I can see. Any thoughts?


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## FrankySaxy (Jan 8, 2014)

I couldn't possibly mimic what you did. (very thorough way of investigation!) i didn't experience what you are experiencing, at least I didn't notice. Could you post the graphs of what you're measuring so I can compare that with my findings. However, I must add that I only used the UR22 and ECM8000 for room impulse measurements.
I should also so say that I bought the Steinberg UR22 after reading up on some internet reviews and experience from another REW user. To what I can say I didn't come accross any other remark about this experience. Of course, it could be that yours is the famous monday morning issue. To be on the save side, you could exchange the item for a new one if you recently bought it. I would. Even if it turns out it had nothing to do with the unit it's the safest and easiest point to start from.
On the other hand, if you have another condenser mic at your disposal, you could try that first. You already have your CSI testing setup...

Good luck and keep us posted.


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## deepthought (Jun 5, 2013)

I can post the graph on Monday when I get back into the office. You can replicate this pretty easily yourself by covering the end of your mic' and then perhaps wrapping it in foam or some other sound dampener. Then go into the RTA window and don't create any signal from REW or any other source. You will now be getting just the noise floor of the system. If you are using phantom power to run your mic then what you need to look for is whether you have a very sharp rise in the noise as the frequency gets lower. In my case the response is flat down to 4khz then rises to a peak of +38dB at 20hz. Nasty.


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## deepthought (Jun 5, 2013)

Solved the issue. Returned the unit as faulty and got a Behringer UMC204 instead.


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## FrankySaxy (Jan 8, 2014)

I hope this will solve the problem. The Behringer was on my short list as well, the double sample rate of the UR22 and the good reviews of the device made me go for the Steinberg.


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## fabricetaboga (Sep 15, 2014)

faut t'il travailler avec une fréquence d'échantillonnage particulière ?


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## FrankySaxy (Jan 8, 2014)

Pardon me? Could you repeat that in English, please?!


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## FrankySaxy (Jan 8, 2014)

Too curious and used internet translation:

*is necessary to make it work with a particular sampling frequency?*

As far as I understand, REW can work with any sampling rate. If you select higher sample rates your can expand the frequency range REW measures to much further beyond. 44.1 kHz Sampling Rate, highest REW measured frequency 22 kHz, 48 kHz SR - 24 kHz REW, 96 kHz SR - 48 kHz REW, etc.

For normal listening conditions lowest sample rate of 44.1 kHz should be enough.

Anybody: correct me if I'm wrong.


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## fabricetaboga (Sep 15, 2014)

Sorry for internet traduction but i don't speak english, thank you for your answer, I think 44.1 is sufficient because the human ear can not hear anything above 22 kh


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## deepthought (Jun 5, 2013)

:yes:


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## deepthought (Jun 5, 2013)

Just wanting to close-off my remarks and not wanting to hijack the thread but I got rid of the UR22. It had the dreaded phantom-rumble issue (quite a good movie title). It wasn't in the serials numbers that were supposed to have been affected but I went into the guys I bought it from and I proved it to them - they took it back without question. I got a Behringer UMC204 - no phantom power issues with this baby! It also has RCA outputs which is cool. 
Anyway, just a note, if you get hold of an UR22 and you are getting screwy measurements in the low frequencies, take it back! To test this, just do a 20hz-20khz measurement with a mic attached and phantom power off - do not run it into your amp to generate any signal then do another one with phantom power on. Find a quiet space or better still cover over the end of the mic' or place it in acoustic foam.
I had a rise from 4khz downwards with a peak of +38db at 20hz. It made any measurements I did meaningless.
If you see a rise in the "measured response" peaking at low frequencies in your unit, you've got a dud unit.


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