# I cant even get the sound card calibration. Help Help please.



## wcjchan (Jul 4, 2011)

Hi,

I tried for couple days now and still have no luck with the first step. Calibration sound card. 
I am using a Motu 2408mkll and have default output fed into default input. But whenever I did the calibration
the results said wrong. Any idea what went wrong with my setup?

Hope there's so eons using the same audio interface and can give me some help...

Thanks 
Johnson


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## SAC (Dec 3, 2009)

Have you checked to see the other devices listed other than 'default'?


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## wcjchan (Jul 4, 2011)

I can see input device PCI 424 but output is default only. Not sure why


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## SAC (Dec 3, 2009)

Without seeing all of the variables and being intimate with the configuration of your computer, its impossible to guess any specifics. But the larger point is that 'default' does not mean that it chooses the correct device, it simply means whatever has been defined as the default device - of which I have no idea. So you do not simply assume that default will select the proper devices!

If you have not chosen the proper routing - meaning having told the machine what devices to use - then you may not get the desired results.

If you have no additional output devices defined - speakers, headsets, etc., then the default most likely refers to the output of the sound card - which will be determined by the input device selected - and that both L& R channels will be the same..


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## jinjuku (Mar 23, 2007)

Simply try:

1. Playing something out of the output to your stereo

2. Try recording something on your input and play it back


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## SAC (Dec 3, 2009)

Even simpler, plug a headset into the output of the sound card.


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## EarlK (Jan 1, 2010)

> Hi,
> 
> I tried for couple days now and still have no luck with the first step. Calibration sound card.
> I am using a Motu 2408mkll and have default output fed into default input. But whenever I did the calibration
> ...



If your computers' OS is Mac / then you'll never get it ( REW ) to work with that soundcard . 

> REW when run on a Mac , ( & at this point in time ) can not "digitally see" the inputs of any soundcard ( of any architecture, be it USB, PCI or FireWire ) that has more than 2 inputs .

> If you want a Mac setup that is guaranteed to work, then copy to the "nth detail", JohnM(s)' Mac setup ( REWs author) which he uses to beta test REW for Macs . 

> Second best is to use the forums' search function to compile a list of hardware combinations that have worked for other Mac users . 
> I've successfully run REW on a Mac Mini ( 2010 vintage ) running OS-10.6.4 , interfaced to the MBox Mini ( AVIDs' 3rd generation USB soundcard ) . 


<> EarlK

PS ; If you're not on a Mac, then my 1st guess is that you're doing something wrong with your "virtual routing", as found in your CueMix DSP™
 "softpatch" software .


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## wcjchan (Jul 4, 2011)

Yes I am with my Intel Mac. Does this mean I get the calibration done? Oh no. 
Can you suggest something or is there anyone have a Mac and able to use REW.?

My whole setting. Mac Intel. Motu sound card. EMC mic. Mic pre..

Thanks again for all inputs. 
Johnson.


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## EarlK (Jan 1, 2010)

> My whole setting. Mac Intel. Motu sound card. EMC mic. Mic pre..


- REW will run properly on just about any Intel Mac ( after OS 10.3 ) .

- Forget about using the MOTU / you don't need it / plus it only offers line level inputs, so it's not worth the effort to include it in the signal chain .

- You can use the Macs built in soundcard for both input & output . Plug your Mic Pre directly into the Mac .

> You'll simply need to obtain ( or build ) the proper adapters allowing you to plug the output of your Mic Pre directly into a single channel of your Macs stereo input .

> Outputs are handled the same .

> Buy a set of cables ( something like the following ). ;
























These will adapt your Macs two 3.5mm plugs into RCA type ends . 

<. EarlK


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## wcjchan (Jul 4, 2011)

Hi EarlK. 


Sorry for my beginner question. Basically does it mean if I play pink noise from my speaker and when the 
ECM 8000 pick up should be equal level. Whatever is higher and lower on the EQ curve is the problem in the 
room? Just try to understand before my build in sound card set up..

Thanks again for all your help. 
Johnson


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## EarlK (Jan 1, 2010)

> Sorry for my beginner question. Basically does it mean if I play pink noise from my speaker and when the
> ECM 8000 pick up should be equal level. Whatever is higher and lower on the EQ curve is the problem in the
> room? Just try to understand before my build in sound card set up..



IMO ( very roughly put );
- One wants to achieve a house curve ( response line ) that is somewhat within a range of plus or minus 2 to 3 db . 

- This is very hard to accomplish because ;

(i) A lot of speakers aren't this flat even within a dead ( anechoic ) environment .

(ii) The acoustics of most listening environments skew the speakers response so dramatically that many wish they had never opened this pandora's box and gazed their eyes on the roller-coaster display ( of their own listening environment ) . :devil: :spend:


<> cheers


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## wcjchan (Jul 4, 2011)

Hi EarlK. 

I tried ur suggestion using the build in sound card and still got no result. I am really hopeless with this program I use the adopter you mentioned from the input and output "earphone out"
The red line had the output fed into input. The white input has the mic pre level in. The white output goes to
my mixer and speakers. 
Unfortunately I still can get the first stage" calibration" done. 
Hope Yiu don't mind to give me some more suggestion where I did wrong. 
Thanks again for all your valuable time. 
Regards
Johnson.


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## EarlK (Jan 1, 2010)

wcjchan said:


> Hi EarlK.
> 
> I tried ur suggestion using the build in sound card and still got no result. I am really hopeless with this program


> Actually, I think your biggest challenge is not really with the REW program, it’s that you are weak in conceptualizing and comprehending the rules governing the nature of "signal flow" within a computer ( ie; where the audio signal goes once it's left the physical wire of the soundcard & enters the computer ) . 

> Also complicating matters, you may not be aware that Apple in their infinite wisdom ( not !!! :rofl: ) split the control of audio signals into 2 places . 
> A lot of people running Macs just aren’t aware of this perplexing fact . 

- The 2nd audio control area ( that Mac-Noobs don't seem to know about ) is called the "Audio Midi Setup" ( application/utility ) .
- It works "hand-in-glove" with Apples' regular Audio Control panel . 
- Here's where Apple hid it ( first pic ) ; Once opened, it looks like this ( second pic ) ;

















> Find it & open it up . Make sure the ""Default" input & output selection is a generic description of your Macs soundcard ( ie'; not your "Motu" soundcard ) .

> Open the regular Mac audio control panel & set all inputs & outputs to "Default" or the name of the generic soundcard in your computer ( it'll look something like the following pic ).
> If presented with the choice of "Line Iput" ( such as you see in the pic ) choose it ( instead of mic, because "mic" would simply be the Macs" builtin Mic ).










> If things have gone well ( to this point & with this control panel still open ) when you talk into your test mic ( still plugged into your preamp ) you should see meter movement on that horizontal LED meter ( in the audio control panel ) . 
> Make sure you're not seeing meter movement caused by wrongly choosing the Macs' builtin mic.

> If you can't get input metering at this point then go back to the beginning and figure out where you went wrong ( or were my instruction were off-track ,,, I can be wrong quite easily since I don't have a Mac here ) .

> Assuming you see good meter movement ( from the correct microphone ) go to the next step ;

> Open REW and set its’ inputs & output device choices ( in the “Preferences” window ) to the “default” choices . The windows ( right under ) can be set to Line In ( & Line Out ) if they show as choices . 
> If they don't show as choices, ( but "default" does ) then choose "default" . 
> If you are uncertain about the choice to make within the REWs' preferences window, then open that window, open the pull-down boxes, make a screen-capture showing the available choices & post a pic here of the area causing confusion .
> If you figure you have the inputs & outputs set correctly ( in REW ) then try running a loopback calibration of the soundcard .



> I use the adopter you mentioned from the input and output "earphone out"
> The red line had the output fed into input. The white input has the mic pre level in. The white output goes to
> my mixer and speakers.
> Unfortunately I still can get the first stage" calibration" done.


> A hand-drawn diagram ( or a couple of good pictures ) of this wiring arrangement would greatly help me confirm what you just said .

> Anyways ; your description of it sounds "correct" . 
> You may not of been getting any sound based on what I just said above ( about the Audio Midi Setup ) .

*Some things to note ;*
(A) The white wire belongs to the "left" input to the computer > therefore to use your mic pre-amp on the white wire with REW you need to change REWs input selection to "left" ( from the default selection of "right" ) . (If you want to change input channels from Right to Left ) make the change only after you have made a proper “loopback” measurement .


(B) The wiring of red to red ( output to input ) is correct when making a loop-back measurement ( it is correct to exclude the pre-amp at this stage ) . Once you successfully make a line level loopback calbration you can move on to doing the same thing but including the input of the pre-amp into the loop-back .

> Now the fact that you can't successfully accomplish a loop-back measurement ( with the above arrangement ) would suggest a couple of things .


 (i) You haven't selected “default” as your soundcard choice within REWs preferences window .
(ii) You may have changed REWs default input from Right to Left . Did you ?
(iii) Your present "default" ( in the Audio Midi Panel ) is still set to your MOTU soundcard .





> Hope Yiu don't mind to give me some more suggestion where I did wrong.
> Thanks again for all your valuable time.


Well, I don't mind ( once in a blue-moon ) tackling a seemingly hopeless situation . :yikes: 

At the end of this road , if you can't pull it all together & the conclusion is one of "Epic Fail", then I'll be recommending that you download & buy    .
> It does seem that most who buy it don't go through this much trouble simply trying to get signal into the program .
> Also, I believe it works with your MOTU sound card ( which is a bonus ) .
> You can download it ( & test it ) for free ( before deciding if you want or need to buy it ) .

From now on, when you run into problems, try to take some pictures ( when relevant ) & post them . 
- I like pictures , forget about writing text & descriptions if a picture can show the problem being talked about . 
- If you don't yet know how to post pictures, then read the Sticky called 
 *Please Read: Posting A Graph by brucek *




Good Luck ( the clock is ticking !! ) <> EarlK


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## pitchtwit (Apr 11, 2011)

wcjchan said:


> I can see input device PCI 424 but output is default only. Not sure why


I was having exactly that problem today when I tried to use REW on his Mac. We couldn't get it working properly in the end. :scratch:


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## pitchtwit (Apr 11, 2011)

wcjchan said:


> Hi EarlK.
> 
> I tried ur suggestion using the build in sound card and still got no result. I am really hopeless with this program I use the adopter you mentioned from the input and output "earphone out"
> The red line had the output fed into input. The white input has the mic pre level in. The white output goes to
> ...


I've been having problems with various soundcards and REW, so just to decrease the number of variables at play here, I'd recommend unplugging whatever you have plugged in to your outputs and inputs on your computer. Disconnect any external soundcards, then do a restart, turn the computer volume up almost to full and then try again. (I'm assuming your computer has it's own built in speakers and it's own built in microphone).

You won't get any good results this way, but at least you'll be able to see if the sweep makes it to the end. You'll also get a graph which will be in no way accurate, but it'll still give you a result/graph instead of nothing. Then you can have a play with some of the different functions - get used to setting the graph limits to sensibly view the energy transfer function (SPL), generate a waterfall or spectogram, check out the impulse response, try out the different smoothings (use 'Graph').

I hope that works. :blink:


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## pitchtwit (Apr 11, 2011)

EarlK said:


> - REW will run properly on just about any Intel Mac ( after OS 10.3 ) .
> 
> - Forget about using the MOTU / you don't need it / plus it only offers line level inputs, so it's not worth the effort to include it in the signal chain .
> 
> ...


Just a question for EarlK:

There's something I've not found a definitive answer to yet, and that is whether there is a difference between using a basic set up similar to the one you mention here, and using a set up with a good quality audio interface (RME maybe - with pretty much a flat frequency response) and a top of the range sound level meter (B&K maybe - using an output from the unit to go to the input of the audio interface).

Has anyone compared the results from each method? I know in theory the software should account for uneven frequency responses in microphone, speaker and audio interface, but it'd just be good to know for sure that is indeed the case.

Tom
:scratch:


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## EarlK (Jan 1, 2010)

pitchtwit said:


> Has anyone compared the results from each method? I know in theory the software should account for uneven frequency responses in microphone, speaker and audio interface, but it'd just be good to know for sure that is indeed the case.


This is currently the only comparison ( between 2 radically different data aquisition systems ) that I have made ( since I don't have a B&K SPL meter to test ) .










One can see that the Radio Shack meter compares very well .

<> EarlK


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## wcjchan (Jul 4, 2011)

Hi Earlk. 


From your test graph. What can we see from graph of the frequencies response if your room.
What is the problem frequency ?
Where can you find the 86 dB as reference blue line? 

Thanks again

Johnson.


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## EarlK (Jan 1, 2010)

Here's that same woofer , with the test microphone only millimeteres from the cone . It now shows a truer response of the woofer ( without the negative effects of room acoustics ) .













> From your test graph. What can we see from graph of the frequencies response if your room.
> What is the problem frequency ?


- One can see some of the negative effects introduced by the room acoustics at the measuring postion ( in the pic from post #17 ) .

- REW confirms ( what I have always heard in the center of this room ) that the area around 140 hz is very problematic .

- Do I EQ 140hz ( downwards ) ? No because where I usually sit ( for music listening ) 140hz isn't that exaggerated .

- Have you had any success yet in getting signal into REW ?


<> EarlK


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## pitchtwit (Apr 11, 2011)

EarlK said:


> This is currently the only comparison ( between 2 radically different data aquisition systems ) that I have made ( since I don't have a B&K SPL meter to test ) .
> 
> 
> 
> ...


Thanks for that. Was the C-weighting ticked in both the experiments? And also, was everything else in the experiment kept the same except for the microphone and pre-amp? They do compare very well.

What about a very standard microphone that gets used to record a musical instrument? Or even a built in microphone on a MacBook Pro? Do you think the shape would still be the same?

:scratch:


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## wcjchan (Jul 4, 2011)

Will be away for the weekend. Definitely will try next week and let u know. 

Thanks.


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## EarlK (Jan 1, 2010)

pitchtwit said:


> Thanks for that. Was the C-weighting ticked in both the experiments? And also, was everything else in the experiment kept the same except for the microphone and pre-amp? They do compare very well.


> One would not want to apply C-Weighting ( EQ ) onto a test mic that is already ( more or less ) flat . ( The resulting "curve" would be highly inaccurate ) .
> Mic Position was the same , as well as playback level . 
> I may have merged any "off-set" ( level difference / I don't remember ) , the reason for my test was to compare the Frequency Response of the two systems .

> BTW; The Radio Shack meter is less than a 1/10th of the investment cost when compared to my Audix test mic & Fast Track Ultra .



> What about a very standard microphone that gets used to record a musical instrument? Or even a built in microphone on a MacBook Pro? Do you think the shape would still be the same?


Calibrated mics ( these days ) are cheap mainly because of the efforts of people like Anechoic .
Buy one from him and run the comparison for yourself .

<> cheers :sn:

BTW; here's the typical response curve for a Shure SM57 microphone ; 










To be of any ( even limited ) use as a measurement mic , one would need to create/write a custom calibration file for it . 

The fact that this is a directional mic would limit it's usefullness ( since it would tend to reject a lot of the room sound ) .


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## pitchtwit (Apr 11, 2011)

EarlK said:


> > One would not want to apply C-Weighting ( EQ ) onto a test mic that is already ( more or less ) flat . ( The resulting "curve" would be highly inaccurate ) .
> > Mic Position was the same , as well as playback level .
> > I may have merged any "off-set" ( level difference / I don't remember ) , the reason for my test was to compare the Frequency Response of the two systems .
> 
> ...


Thanks for that info. How do I make a custom calibration file? I have a Yamaha Pocketrak 2G handheld WAV recorder, which actually gives a really good frequency response (I compared it to a B&K 2270 I borrowed). In terms of directionality, it does seem to be pretty good - room acoustic is always clearly audible on recordings - but are there any ways to test this?

:scratch:


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## EarlK (Jan 1, 2010)

> Thanks for that info. How do I make a custom calibration file? , ,,,, snip ,,,,,


- Hmmmm , I thought there was a sticky describing the process but I couldn't find it .

- OTOH, here's a thread  *that talks about the process somewhat . *


>> Anyways, here are all the steps needed ( I believe ) to *make a custom calibration file *<<

- To create a custom calibration one needs to download any one of the available calibration files from THIS PAGE !
- Open this file in a text editor .
- Study the ( text based ) construct/format/arrangement , ( then make a copy ) and enter in your own ( guesstimated ) numbers . 
- Save your copy.
- Add ".cal" to the end of the file name ( instead of .txt or whatever is there if it's not ".cal" ) .
- Select this ".cal" file from within REW as your microphone calibration file .

*NOTES:* 

_ You can use space, tab or comma to separate the values on each line.
[ii] The more descriptive frequency points you add to your correction file , the more accurate the compensation curve will be ( especially with a mic that has a "roller-coaster" FR response ) . 
- For example, take a look at all the low frequency points used in the Radio Shack calibration files .

<> EarlK_


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