# Eurorack UB802 v XENYX 502/802



## Blueshirt (Mar 19, 2013)

Hi,

First post. Just got REW and trying to get prepared to take some measurements of my audio room to figure out room treatments needed.

I've been reaading a lot of the threads but I'm confused at this point. 

The REW Cabling and Connection Basics Guide says Xenyx 802 then 502 but shows a picture of Eurorack UB802.

Which one is the recommended on for use with the ECM8000? Price is not much of an issue. just looking for accurate and simply to use/setup.


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## HifiZine (Feb 7, 2013)

Hi, it's simpler to use a combined preamp/USB interface. I've recently used/reviewed the Focusrite Scarlett 2i2 and MOTU Microbook II (more powerful but definitely a "learning curve" unit). Either of those, with a calibrated EMM-6 (or ECM) from Cross-spectrum Labs, will give you something that will work reliably and be fairly "future proof".


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## Blueshirt (Mar 19, 2013)

Thanks but it sure doesn't sound simpler.

Simpler to me would be the Dayton UMM-6 USB microphone. It can plug right into the computer. No?

Am I missing something?


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## HifiZine (Feb 7, 2013)

Uhm... well, a lot of things plug into computers. Sorry for responding, my bad.


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## Blueshirt (Mar 19, 2013)

I apologize if my response came off unappreciative (was typing from phone)

I'm really new to all of this so when I looked at what you suggested there were a lot of buttons!! :yikes:

I'm sure I could figure it out somehow but the fact that there is step by step guides on the other mentioned made me a little comfortable.


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## HifiZine (Feb 7, 2013)

Hi, the setup with a USB interface is shown in the last diagram of the setup guide:


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## fastleo63 (Apr 26, 2006)

Hello,
I just bought a XENYX Q502USB mixer/soundcard. 
Having read the REW guides, I tried to set up a test measurement with my mic (Behringer ECM8000) inserted in Line 1 mic input, and test signal outputted to one channel of the 2-track pin-jack output (tried the jack main out, too).
But when I start to measure, seems that the REW input channel wasn't the microphone, because I obtain a perfectly flat response from 20 Hz to 20 kHz... 
Anyone can help me to have a correct setup of this controller? I bought the Q502USB especially for the full-duplex feature, but seems difficult to me how to use it...
Thanks a lot,
Leo.
EDIT: SOLVED!
Seems that if in REW I use the WDM drivers I cannot choose the correct mic input channel (in my case, the right channel).
For test signals output I choosed the left channel, so all is finally working, now.


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## draki (Dec 14, 2012)

I have XENYX Q502USB (recognized as "USB audio codec") on hand with ECM8000 mic.
Using Java / 48KHz/ output and input are "speakers USB audio codec" and "microphone USB audio codec", level set to -12dB.
Input mic "Z".
The problem is that REW shows too high input level (o dB headroom), also when testing levels even small level PN is shown as "OVER" on the SPL meter. 
Obviously there is too high digital level somewhere.

Can anybody please help solve/explain this behavious with Q502USB/ECM8000? 

There are no problems with UMIK-1. But a friend is setting up with the a/m Behringer so trying to help.

Thanks in advance,
Draki


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## JohnM (Apr 11, 2006)

Check that the gain setting for the mic input isn't too high and that there isn't some monitoring active.


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## draki (Dec 14, 2012)

Thanks for responding, John.

The gain is very low (actually this is happening with gain set to min).

As far as I can see (or can't see) there is nothing on the device about monitoring.
The mic is in the mic input, USB to the laptop/REW, main out from the Q502 to the amp (tried both L and R).

Can't figure it out...? It's supposed to be simple.

Is Focusrite Scarlet 2i2 "REW-approved" in practice? There is a chance for exchanging the Q502 for the 2i2, but only if the outcome is proved to work...


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## JohnM (Apr 11, 2006)

There are a fair number of threads featuring 2i2 in the main REW forum, so best search there and see what people had to say. No reason it shouldn't work, but the same is true of the Q502 and from posts above looks like it has worked for others. You may want to try a simple loopback connection on the 502 using the line input and see if that can be made to work correctly.


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## draki (Dec 14, 2012)

Xenyx Q502 returned. In _my_ case it didn't work, the recording levels were always peaking (in HolmImpulse also). IMO the "monitor" signal is always present and that creates the problem. _Again, IMO_. 

New device Scarlett 2i2/ ECM8000 (uncalibrated): it works, kind of... The thing is that the level raeadings via the SPL meter are not realistic. At subjective level of 75 dB, it would read 110 dB!! If "calaibrate" is set to 75 dB, then the measurements are indeed abt 40 dB down. Also if SPL reading is made to show e.g. 75 dB after calibration, the SPL level won't change with incerasing/decreasing acoustic level. Something is not quite OK (again, in this particular case, I know of no other reported problems?). I even reloaded the REW 5.1 version, no difference. 


Also, since this was first use of the ECM8000 mic (non-calibrated), we noticed a huge peak at 50Hz, about 35 dB, narrow Q. Compared to the same-spot/same-speaker measurement with UMIK, where it is non-existent. The rest of the curve,well, almost overlapping with ECM's curve dropping down early after 1KHz and ending about 6-8 dB lower than UMIK's. In other users' experience, is this typical ECM8000 behaviour?

For a check, used the "standard" setup: UMIK-1 and laptop's line (headphone) output. Works OK. Go figure...

Either we are doing something wrong, or something else is at play, don't know. Anybody wiser and more experienced, please shoot.


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## JohnM (Apr 11, 2006)

The SPL meter cannot read correctly until it is calibrated, you need to tell REW how the signal level from the mic corresponds to an SPL figure, hence the step to calibrate the SPL reading. Before doing that check that the input level actually changes when the sound level in the room changes, of course, to make sure that input selection is correct.

The 50 Hz peak is almost certainly mains hum pickup, if you switch to the RTA you can see what is affecting that (for example, does it reduce if you use a shorter or different cable from the mic).


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## draki (Dec 14, 2012)

I did a loopback connection on the Scarlett 2i2.
At least this works. The REW level bar reacts to the gain changes, and the measured curve is pretty straight.

But no success with the mic (ECM8000). Still doesn't react to a room sound volume level changes while testing levels. Also with genrator' pink noise the SPL doesn't react. Even after "telling" it that a level is, say, 75 dB, it just stays there..?


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## JohnM (Apr 11, 2006)

Are you sure the phantom power was on when using the ECM?


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## draki (Dec 14, 2012)

Phantom power ON, yes.


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

Don’t think you’ve given us any info on your computer or your connection scheme? If you’re using a Mac there can be issues. Connections should be like the picture below. Make sure you have the 2i2’s monitor turned off.










Regards, 
Wayne


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## draki (Dec 14, 2012)

Thanks Wayne.

The connection is OK as per diagram.Monitor to OFF.
But, I have found the same 50 Hz peak also on Holimpulse.
Also have audible hum when made a simple voice recording on Audacity (just for checking).
The mic is OK (checked), so are the cables. There seems to be a hum generating from the Scarlett 2i2. It is not audible without signal, but is clearly visible on the measurement graphs (REW and Holmimpulse) and is clearly audible on the replay of the recording in Audacity.
Will have to check the Scarlett. It was bought brand new, first user... 
Did anybody else encounter similar problem with 2i2? It is not mains powered, but via USB.


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## draki (Dec 14, 2012)

Hi All.

Update on the reported ECM8000/Focusrite 2i2 hum problem (50 Hz peak), and subsequent non-responsivness to the SPL level changes:

Long story short, *it was a faulty microphone cable!!! * Even though the cable was bought brand-new, factory sealed etc. My testings with a MM showed all pins correctly, and no shorts. Even so, the big hum problem was easily repeated in the store, and they exchanged the cable. 

Now the combination (ECM8000/2i2) does work indeed as expected.

Thank you all for participating in the problem-solving.

Rgds, Draki


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

Wow, that's a pretty rare problem with a mic cable, the last thing I would have expected. Glad you were able to figure it out! :T

Regards,
Wayne


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## draki (Dec 14, 2012)

Yes, it was strange since the cable did measure OK with the MM test. Still puzzled.:scratch:
Now, I am wondering if the Q502USB, which I had for one day and had exchanged for 2i2 on the premise that it was always peaking and (I thought) there was something wrong with the "monitor" function, would have worked OK after all...


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