Is soundcard Calibration required with UMIK-1 ?

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.

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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...

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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.

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 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:

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

Here's the SPL with 1/3 smoothing:

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 ...

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)