# REW & Mbox calibration...



## mbastami (Jul 1, 2011)

Hi everyone ...i am having a problem with calibrating the soundcard of the Mbox , REW can see the box and i 
followed instructions such as Connect the soundcard's line output directly to its line input - use the channel that will be used to make measurements which should be the same one that has been selected in the Input Channel controlor input & Mbox analog ( i chose Mbox mic/line 1 for the input & Mbox analog /digital1 for the output)...when i press the calibrate the input and ref input are clipping in red and i cant control them from the Mbox ,i am using laptop with windows 7 so what am i doing wrong...thanks


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## EarlK (Jan 1, 2010)

> ,,,,,,snip ...when i press the calibrate the input and ref input are clipping in red and i cant control them from the Mbox ,i am using laptop with windows 7 so what am i doing wrong...thanks ,,,,,,


Please provide a working hyperlink to the actual model of your Mbox product ( or a link to it's user manual ) .

To get you started, here's a link  *to AVIDs Homepage for the Mbox series of products . *


<> EarlK

FYI, you may have the Mbox setup to monitor its input ( sending it directly back to the output / this is a "no-no" ) . 
-This creates a loop of runaway feedback ( overload ) . 
- If that's the case , turn off the Mboxs' input monitoring feature ( wherever it's located ) .


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## mbastami (Jul 1, 2011)

Link to original Mbox
http://akmedia.digidesign.com/support/docs/Getting_Started_Mbox_28599.pdf
and its input monitoring is set to 0....and what is that instruction in the part of calibrating your soundcard that says Connect the soundcard's line output directly to its line input !!? thnx


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## EarlK (Jan 1, 2010)

Thanks for the link to the O.M. !

Here's how you need that "Mix" control set for REW .












> and its input monitoring is set to 0....


The drawing within the manual doesn't show numbers // so if "0" means to the far left ( on the mix knob ) / then you've got it set wrong .



> and what is that instruction in the part of calibrating your soundcard that says "Connect the sound-card's line output directly to its line input !!?"


That instruction couldn't be any more direct . What about it, don't you understand ? ( maybe for instance,, why bother ?? making a calibration ) 

*The WHY ?? is *One makes a ( temporary ) "Loop-back" to measure the linearity of the soundcards output & input circuitry for each & every SC to be used by REW . REW creates a calibration file ( auto-magically ) from this info to flatten out ( compensate for ) the inevitable less thaan perfect responses of teh card. This way, what you measure isn't also skewed by the response of the soundcard .

<. EarlK


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## mbastami (Jul 1, 2011)

Hi Earlk thanks for the reply and take it easy man u don't have to be more aggressive then u should (not all people have your experience as a assume or just understands right away with no previous experience with measurements ) anyway i did exactly what u said to make a loop file to compensate (i checked the loop in the analysis and connected the output (analog 1) to the input (Mic/line 1) and what about the (Time ref) analog 2 output and input should i connect them too (please bare with me in a step by step) because i tried both configurations and i still could not control the input the best i could get was (0 to - 0.1) on both input and ref input and the result was CLIPPING WAS DETECTED that cant be used for measurements (both knobs at hard right ) since u have the picture ...i am trying to do things right step by step 1st the sound card then the levels then the SPL ... AM I MISSING SOMETHING WHICH IS NOT CONNECTED because the connections that i have when i do that is only the loop cable in and out of the Mbox.


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## EarlK (Jan 1, 2010)

> AM I MISSING SOMETHING WHICH IS NOT CONNECTED because the connections that i have when i do that is only the loop cable in and out of the Mbox.


- You're not missing any connections ( currently ) to make a simple soundcard calibration ( with the loop-back on channel 1, from "out" to "in" ) .

- No, you don't need to make a loop-back on channel 2 .

*The Loop-back Calibration ( Stress ) Test *

Generally Speaking, a failure to successfully accomplish this ( stress ) test can point to any of the following conditions ;

(a) A broken Sound-card .
(b) A lack of the users' familiarity with the workings of the audio features ( hardware or software specific ) for the sound-card he has chosen to work with . 
(c) A lack of the users familiarity with the audio features for the OS he's currently working with . 
(d) A broken copy of REW .

- So far, I don't see any evidence of item (d) , though I'm sure it happens from time to time . 
- (AFAIK ), Items (a) to (c) are the sole responsibility of the newb user to have a firm grasp of ( before posting here ) .
- ( & yes, I assume this applies to any new user of * "free"* , 3rd party software such as REW ) . 

So ;

* (I) Your Overload Problem : *

2 Solutions ( you'll need to implement one or both )

*(i) Too Much Gain *

- You need to turn down the gain ( somewhere ) to keep from overloading the input coming into REW or your soundcard ( to make a successful calibration ) . 

- There are a few gain ( level ) control areas ( that you need to identify & know their workings inside-out ) ;

(A) On your soundcards' hardware // there might also be a software based "Audio Control Panel" specific to your Mbox soundcard that you should locate & identify how it works and what it works on .
(B) The Windows7 Sound Control panels _can_ control levels in & out of the computer ( as long as the your soundcard hasn't disabled them ) . 
- In Win7 , here's what they look like ( when they are active & in use by the built-in USB sound-driver directing traffic for the Behringer UCA202 ) ;

















(C) REW also has volume control levels within the preferences window that ( sometimes ) are active, if your sound-card hasn't disabled them . Again, here's what they look like when a UCA202 is plugged-in & present .










*(II) Feeding-Back Signal ( input to output ) *

(i) I've previously shown you one location (the "Mix" control on the front of your soundcard ) where you need to make sure that you don't dump input back to output .
(ii) There may be a similar software based mixer ( that accompanies the Mbox ) that has the same function ( that you'll need to find ) and rectify ( ie; stop feeding input to output ) .

Here's the software based mixer for my M-Audio soundcard . 
- I've noted the faders that must be kept down at zero ( or else they create a runaway feedback loop such as you appear to be getting ) .
- You need to explore whether or not your soundcard has anything similar that you need to graple with .











<> EarlK


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## mbastami (Jul 1, 2011)

Thanks a lot EarlK actually i tried all that before and was successful with calibrating my internal laptop soundcard, the problem that i am having is controlling the Mbox input but after intense net search i guess the original Mbox has no control panel with a mixer but Mbox 2 and newer versions have it so i guess i will have to upgrade or get an M-audio ...until i do that i will keep searching for a software that can control the original Mbox...thanks again (u r a great help).


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## EarlK (Jan 1, 2010)

Hi,

- I'm thinking that your Mbox is so old that it comes from a generation of hardware/software products ( made by digidesign ) that were intentionally crippled (by digidesign ). They were most likely crippled so that only their soundcard could be used with ProTools ( & vice-versa ) .

- You must be running an old version of LE according to Pro Tools LE for Windows Compatibility & Upgrade Information . 

- Have you ever successfully used this old Mbox with any other audio software, other than ProTools LE ?

- BTW ; which version are your Mbox wave-drivers ?

*Anyways ;*

- Take a look at  * AVIDs Knowledge Base*  to see what they say about the  *Digi MME Helper . * 

- This little utility was specifically created to help enable AVIDs ( older ) Wave drivers ( like your original Mbox soundcard ) work with other programs ( other than ProTools ) . 
- This utility is old ( it's from XP days ) , so who knows if it'll work properly with Win7 . 

- Anyways, download it, try it out ( load it up with the progams you want to use with the Mbox ) & see if you can get your Mbox to talk nice to REW ( otherwise, yes it may be time to junk that card ) .


To Use:
1. Run the Digi MME Helper.exe 
2. Click on the "Add..." button 
3. Browse to the applications that you would like to be supported by WaveDriver 6.1.1 and press Open 
4. Press the Update button, which will update the Registry

<> EarlK

PS :  A Good Thread To Read .


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## mbastami (Jul 1, 2011)

Hi EarlK... Digi MME made no difference with REW cant find any new driver in sound panel nor in Device Manager, actually i never tried to use the Mbox with any other soft ...the driver version 8.0.0.314 is what i have with Pro Tools 8.0 LE.


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## EarlK (Jan 1, 2010)

*Re: REW & Mbox calibration...( Last Try )*



Barish said:


> I have tested a commercial studio's control room with success today using a Macbook Pro 2.4GHz (MB133B/A with OS X 10.5.6) and an M-Box Mini + PTLE 7.4.2. The trick is that you need to launch Pro Tools along with REW in order to control the M-Box, since the Digi drivers won't let you control the interface from System Preferences Sound Pane.
> 
> - Just launch PTLE and start a new session with two mono audio input tracks assigned to either of the inputs, and a stereo master fader, all set to 0dB. Mute the input tracks so that they don't relay what's at the input to the output, and then leave it as it is all throughout the test.
> 
> ...




The above quote is from an older ( 2009 ) thread called ;  *REW Digidesign Interfaces . *

Do as Barish suggests within ProTools ( even though he's on a Mac ) . Just make sure you label and save this configuration as a "Session" .

The theory here is that your soundcards WDM ( Wave-Driver ) settings are "frozen" in place, to whatever driver settings were last used by you when you last used "ProTools" . 
- If this " driver reset/reconfiguration" works, it means you must always open up ( & then quit ) the ProTools Session which has the special REW configuration ( all assuming that you've used ProTools in the meantime to do some more recording ).

I'm thinking this "reset" might not have worked for some ( ie; member "PTrust" ) because he hadn't yet saved the new ( REW/ProTools ) session & therefore ( goes my speculation ) the drivers internal settings where still ( improperly ) configured from his previous ProToolsLE session . 

- At least, that's my "best-guess" for the moment ( in trying to reconcile the conflicting experiences within that thread ).

<> EarlK


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## mbastami (Jul 1, 2011)

*Re: REW & Mbox calibration...( Last Try )*

Thanks EarlK i'll try it and let u know...


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