# Is soundcard Calibration required with UMIK-1 ?



## Nitrofreakman (Feb 18, 2013)

Hi,

Apologies if this has been covered before, I've been looking for a solid answer for the last 2 days/night so that I can use REW to improve the sound of my home theatre. I'm very new to REW/room measurement, but eager to learn, it's all just a little overwhelming at this point. I also thank you in advance for your patience.

I just received my Umik-1 a couple of days ago and I'm a little puzzled about setup. I have a 2007 iMac, running Lion OS. I'm using the latest beta version of REW, which runs a little more stable on my machine ( when REW 5 was installed, it would constantly quit unexpectedly, the current beta version still does this, but less frequently ) My plan is to use the 'optical out' that's built into the headphone jack, and connect it to my Yamaha AVR to run the tests, through my HT speakers. I don't have an external EQ/DSP unit ( yet ), so all adjustments will be made manually through my AVR's PEQ once I have the results from REW. I would like to build bass traps and diffusers once I figure out.

Do I need to calibrate the sound card in my iMac when using the Umik-1? I did try to calibrate it, but I don't think I did it properly. I connected the headphone jack to the mic. Here is the results, calibrated at 44.1k:









Afterwards, a fellow forum member told me that it isn't necessary to calibrate the soundcard with the Umik-1. If that is the case, then I will clear the cal file. 

Another question, for my input selection under the REW soundcard tab, I am able to use either Umik-1 ( with 48k option only) or Soundflower (2ch) which I can set to 44.1k or 48k, both option enable the use of the Umik mic, but what is the proper option/settings ? I thank-you so much in advance. Keep up the excellent work on REW.

I have to go to work soon, but will keep an eye on this thread with my iPhone lol, I plan on doing some more late night tinkering when I get home late tonight:bigsmile:


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## fusseli (May 1, 2007)

I can't think of a situation where you wouldn't want to calibrate your soundcard, but using the optical connection will make that a little trickier. The soundcard sweep you posted looks ordinary to me. If you could loop back an analog output from your AVR you could use that to make the loop to create a soundcard .cal. I don't think using either card at 44.1k or 48k will make a difference in your measurements. I'd say use whichever you believe is the "nicer" card.


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## ceh383 (Jan 26, 2013)

The UMIK-1 is a USB device, it does not require the use of a sound card. As no sound card is needed, no sound card cal file is needed as well. A mic cal file is recommended, and can be downloaded from MINIDSP. I use the HDMI output on a Windows PC for REW measurements, so, I can't offer any help with optical output on a MAC...


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## Nitrofreakman (Feb 18, 2013)

fusseli said:


> I can't think of a situation where you wouldn't want to calibrate your soundcard, but using the optical connection will make that a little trickier. The soundcard sweep you posted looks ordinary to me. If you could loop back an analog output from your AVR you could use that to make the loop to create a soundcard .cal. I don't think using either card at 44.1k or 48k will make a difference in your measurements. I'd say use whichever you believe is the "nicer" card.


 Thank-you for replying. I'm unsure about the accuracy of soundcard sweep I made because I didn't have the option of choosing a left or right input/output because I used the headphone and mic jack on the iMac, and looped them together with a double ended 1/8" male connector. As far as looping my AVR, it may be possible to use the toslink out connector on my Mac, and use the front panel toslink input on my AVR to loop in, and then I could use the AVR headphone jack to loop out and back into Mac mic input jack..if that makes any sense ( I'm so new to this that I could be out in left field ) Would REW allow me to make the .cal file if I tried that route? Thanks again for your feedback.



ceh383 said:


> The UMIK-1 is a USB device, it does not require the use of a sound card. As no sound card is needed, no sound card cal file is needed as well. A mic cal file is recommended, and can be downloaded from MINIDSP. I use the HDMI output on a Windows PC for REW measurements, so, I can't offer any help with optical output on a MAC...


 Thank-you also for replying. I think your answer is a great help to my situation..I bought the Umik for the simple reason that it was USB( plug and play so no messing around with things beyond my knowledge aside from loading the Umik cal file, easy enough ), also, MiniDSP being a forum sponsor, I felt it was a safe choice, since I'm new to the technical side of the HT world( all I cared about back in the 90's was how good it sounded, now that I'm back into this great hobby, and from scouring various forums and reading about room treatment, I started to question if I ever really knew what good sound was:dumbcrazy:, since I'd never thought about room treatment, and room EQ software/hardware wasn't very affordable )

You are the second forum member that tells me I don't need a souncard cal file, and plug-and-play by tradition is what it is, so I'm thinking that must be the case with the Umik, that's what makes sense to me, but I'm less than novice at this. As for connectors, I should be able to get an audio signal to my AVR via toslink. I have a video out jack ( mini DVI ), and an HDMI adaptor for it to run video out..I don't think it'll send an audio signal through that HDMI setup because it is a video out on the Mac. Thanks again for your input, I'm happy listen(read) and learn from experienced members.


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## ceh383 (Jan 26, 2013)

I'm glad to help, at least hopefully help. I wouldn't call myself experienced in this hobby, I've been out of audio for many years. The last time I was even remotely serious about audio, graphic eq's were the best you could do, and room treatments for the home were unheard of. In this world of DSP's, PEQ's, etc, I'm as new as they come...


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## Nitrofreakman (Feb 18, 2013)

We're in this together brother! lol 

I was just googling ASIO drivers for Mac, out of curiosity since I'm clueless what they are, and found out that Macs are built with CoreAudio, which is apparently very good..one tidbit of relief for me. The Soundflower option has up to 16 channels, don't ask me what to do with them though lol.


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## AudiocRaver (Jun 6, 2012)

A little extra detail, if it helps... With the USB mic input, there is no way to calibrate only the OUTPUT of the sound card without a calibrated AC voltmeter good to 20KHz, which very few of us have other than engineers and repair techs. Any loopback cal you do will reflect a conglomerate of output and input response curve effects. Ideal with a USB mic input is to use HDMI for audio out, then the sound card is no concern - and any part of the system affecting frequency response outside your analysis computer/sound card will be in the chain anyway in normal use so you WANT to see its effect in your measurements. With a USB mic and analog output, a best guess would be that using _no sound card cal file_ will introduce less inaccuracy than using _a sound card cal file including both output and input effects,_ and those are your only choices, so go without the sound card cal file.:bigsmile:

Edit: Make sure you have the latest calibration file for your UMIK-1 mic. MiniDSP had some trouble compiling test data into the calibration files awhile back, and users had to download corrected files. That should all be straightened out now. Check out this thread for details.


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## Nitrofreakman (Feb 18, 2013)

AudiocRaver said:


> A little extra detail, if it helps... With the USB mic input, there is no way to calibrate only the OUTPUT of the sound card without a calibrated AC voltmeter good to 20KHz, which very few of us have other than engineers and repair techs. Any loopback cal you do will reflect a conglomerate of output and input response curve effects. Ideal with a USB mic input is to use HDMI for audio out, then the sound card is no concern - and any part of the system affecting frequency response outside your analysis computer/sound card will be in the chain anyway in normal use so you WANT to see its effect in your measurements. With a USB mic and analog output, a best guess would be that using _no sound card cal file_ will introduce less inaccuracy than using _a sound card cal file including both output and input effects,_ and those are your only choices, so go without the sound card cal file.:bigsmile:
> 
> Edit: Make sure you have the latest calibration file for your UMIK-1 mic. MiniDSP had some trouble compiling test data into the calibration files awhile back, and users had to download corrected files. That should all be straightened out now. Check out this thread for details.


Thank-you so much. I will clear the sound card cal file, and try REW without it. I would love to use HDMI for audio, but in my case, I don't think it will work because I'm using a mini DVI ( the video out jack on my Mac ) to HDMI adaptor, so I'll be surprised if audio gets routed through it. The headphone jack doubles as a mini toslink optical out, so this is my only current option. I'm not sure if the results would be similar to using HDMI for audio? Thanks for the information, it helps a great deal


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## JohnM (Apr 11, 2006)

Use soundflower as the input source on the mac, per John Reekie's instructions linked from the sticky thread. Your soundcard cal trace was fine, but soundcard cal is not used with USB mics.


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## Nitrofreakman (Feb 18, 2013)

Thank-you for confirming that John, and for your help. I set it up as John Reekie outlined, the mic appears to work, aside from one thing, my noise floor will not go lower than 52dB, no matter what I do to it:










I got home quite late from work last night and decided that I just had to try the mic/software ( I couldn't stop thinking about it at work:huh. I hauled my iMac over to my AVR and connected it. I ran pink noise from the Generator into my AVR via toslink, and set the volume to 75dB using the REW SPL meter, and hit 'Measure'. I kept getting low input volume messages, even though the volume was set loud on the AVR. Now more puzzling is that when I check my dB level with the REW dB meter, all appears to be well when a pink noise signal is fed through the AVR, it's only when I want to 'measure', or 'check levels', that the mic barely picks up anything, even if I tap on it. It was getting too late (3am), and I was pretty tired, and had to clean up my mess to keep my wife happyaddle:, decided to call it a night before my head exploded:scratch:. I started to think maybe the mic is the problem..maybe not..I'm too new to this side of HT to make a judgement call.

I decided that I would try to work on this some more today, but didn't haul my Mac over to my AVR this time, instead I used the Altec speakers connected to my Mac for testing. It was basically a repeat of last night..dB levels seem fine until I try to actually 'measure', or 'check levels', then all of a sudden, my input levels drop drastically. I took some screenshots of my configuration.

UMIK-1 set to 0dB as suggested:










Levels reading with Soundflower set to 0dB :










Levels with Soundflower set to MAXdB :










My current config..I don't have a 'soundcard' option other than what's in the pop up menu of line-in, but what is shown is one config that worked( kind of ? ) with REW:










These are the LineIn input/output options I have ( the headphone jack doubles as a mini Toslink out and appears when connected, but there are no available adjustments for it in the Audio MIDI Setup App ):



















I'm kind of lost about what my next step should be. I will try my son's Windows7 laptop ( I was trying to avoid using Windows ) to try and figure out if it's a mic issue ( it doesn't appear to be the mic, maybe the cal file '7000352' ?? I don't know:coocoo: ), or if it's software related..REW 5.0 crashed on me quite often, but the beta was more stable. Any suggestions would be great right now. I was hoping that with a USB mic being plug-and-play, the process would have been more straight forward..I got 'plug', but I got no 'play' :rubeyes:


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## Nitrofreakman (Feb 18, 2013)

Oh ya! Sorry for all the pictures..I'm just trying to include as much info as I can that may help. Thanks.


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## JohnM (Apr 11, 2006)

It is probably OK, the mic is capable of measuring very high SPL so shows low levels under more normal conditions. Just ignore the warning and see how the measurement looks.

The 52 dB reflects the noise floor of the mic.


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## Nitrofreakman (Feb 18, 2013)

OK, good enough John, I feel much better about my mic now..it's quite a relief to have you confirm some of these things..THANK-YOU.

I decided to try my son's Win7 laptop, via HDMI through my AVR. When I did a level check, I got the same message, but at a different dB value..so I ignored it and ran the test tone in 7 channel party mode ( my only other option appears to be L+R+Sub ), with the front L/C/R speakers set to 'large', and the remaining 4 rears set to small. Here are the screenshots, now I have to learn to make sense of the data:rubeyes:

SPL/Phase










Waterfall










Spectrogram










All SPL










Distortion










Decay










RT60










GD











Like I said, I have to figure out what it all means, I understand some of the things, but I have plenty of learning ahead..my hope is that the graphs look reasonable, and that the mic/software are doing their thing, and that anything that's way out is what I have to focus on fixing/adjusting in my HT room/system. I will haul my iMac over again and try to run the sweeps again, now that I have a general idea what to expect from the testing. 

Any pointers I should consider, or things I may have done wrong ( read: probably did wrong :R ), please let me know


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## Nitrofreakman (Feb 18, 2013)

Here's the SPL with 1/3 smoothing:


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

See that little camera just above the graph to the left that says “Capture?” Click on it and you can save the graph as a .jpg. No need to do screen shots. :T

Regards, 
Wayne


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## Nitrofreakman (Feb 18, 2013)

Wayne A. Pflughaupt said:


> See that little camera just above the graph to the left that says “Capture?” Click on it and you can save the graph as a .jpg. No need to do screen shots. :T
> 
> Regards,
> Wayne


Thanks for the tip Wayne..any tidbit of knowledge I can absorb is a plus for me..I feel a little lost at the moment, I'm not really sure how to interpret most of the data from the graphs, or where to start. I will likely run several tests before I start thinking about room treatment..but to do that, I need to know what all the data means :scratch: My biggest problem ( and I'm guessing it's common to most ) is lack of time, and the free time I do have is usually after midnight, not the most ideal time for high-volume testing lol. 

Any links to help me ( or other members who may be interested ) in learning how to decipher the data from testing with REW would be great. I have the day off today, so will likely be in the mancave tinkering ( in between my daughter's nap-times :bigsmile: ) 

Thanks again for your input.


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## sKiZo (Feb 9, 2013)

Yet another soundcard calibration issue ... kick me and tell me to start my own thread if you so desire. <G>

Using a laptop with a Behringer UCA202 and a Dayton mike ...










Doesn't look much like what I see in the book. So, like ... huh?

- I did go thru the setup instructions and matched the volume within a db on *I* and yes, *O* using the windOHs volume control ... all volume settings in REW are grayed out, and the system is set to default device and default input/output. Input sweep level is set to -9.0 as that seems to get closest when setting the levels.

- Did a double loopback (both channels), then left only, then right only ... with the same results.

- Have tried it with _Use Loopback as Timing Reference_ checked and unchecked on the Analysis tab. Doesn't seem to make a difference.

So far, haven't done any SPL calibration, but from what I see, the soundcard is the first step. Ignoring the macro curve, I see this one is within a db high to low thru the usable frequency range, so, at risk of repeating myself ... huh? Hoping there's an easy fix, or maybe just an "ignore it" in my future.

PS ... I thought maybe the laptop's onboard sound might have been playing games with me, so I disabled that completely from the control panel.

PPS ... apparently I can't delete posts either, so ... mods please? The next two can like ... go away ... if you'd be so kind. Thankyewverymuch ...


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## AudiocRaver (Jun 6, 2012)

The amplitude scale is very "zoomed in." Your reading is down only 3 db at 20 Hz, which is fine. The high frequencies roll off a lot faster, down 3 db at 3 KHz, which does not sound right for a sound card set for full bandwidth.

1. Check/recheck for any onboard effects or EQ settings, disable all.
2. Show us another plot "zoomed out" so we can see a 20 to 40 db range of readings.

Edit - Just noticed you have 1 dB of gain. Ideally a cal file should show 0 gain at mid frequencies. You might recheck your calibration process for how the gain is occurring, it should not be there.


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## Nitrofreakman (Feb 18, 2013)

sKiZo said:


> Yet another soundcard calibration issue ... kick me and tell me to start my own thread if you so desire. <G>


..I wouldn't even think of it, we're here for the same reason my friend..post away! ( ..you never know, I just may learn something too.. ) :bigsmile:


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## sKiZo (Feb 9, 2013)

I did figure out my little problem ... on the Behringer UCA202, you need to set the monitor switch to OFF.



















It's the little things that can drive you CRAZY BATS IN THE ATTIC I AM CRAZY BARS ON THE WINDOWS ...

(phew ... sorry bout that - won't let it happen again till the next time)


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## AudiocRaver (Jun 6, 2012)

There you go. Excellent results.

So much trouble from such a little switch, who would figure it? Actually, I should've thought to mention that as a possibility, as it came up as an issue in another thread a month or so ago. Beg pardon for my not remembering, but it all turns into a blur after a few days.


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## sKiZo (Feb 9, 2013)

Is there a sticky for REW hardware issues? I'd think most any hardware we use to get the in/out thing going would have their own little quirks.

Speaking of hardware ... anybody else got one of these old gems laying about? Had this since I was just a young sprout, back in the stone ages.










I'd give some more info in it, but it apparently pre-dates the use of model numbers and I can't find anything on it on the web. Seems to have done an admirable job over the years - mostly just trying to find out how loud it was when my ears started bleeding ... if anybody happens to have a calibration file for it ... nudge nudge ...


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