# Can't get input to match output on calibration...



## cruzmisl (Jul 1, 2007)

Hi All,
I'm trying to generate a cal file for my soundcard but I can't seem to get the levels to match no matter what I do. I'm still able to generate a cal file and it looks normal but I'm unsure if it's OK. There is about a -10dB disparity between the two. 

Any ideas?
Thanks,
Joe


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## brucek (Apr 11, 2006)

> There is about a -10dB disparity between the two


Do you mean the input and output VU readings when running the calibration routine?

The output is adjusted by Sweep Level and the input is adjusted by Input Volume.

What is it specifically that is not working for you?

I trust you're using a _stereo_ cable with stereo connectors between line-out and line-in to do the calibrate?

brucek


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## cruzmisl (Jul 1, 2007)

Bruce, that's exactly what I am talking about. If I reduce the sweep level the output also gets reduced.....regardless of what I do there is always an 8.0dB difference. I am using stereo connectors, with a SB live and Vista.....

Any other ideas?


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## brucek (Apr 11, 2006)

> If I reduce the sweep level the output also gets reduced


But that's what it is supposed to do. Are you not able to increase the input level to match the output level?

brucek


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## cruzmisl (Jul 1, 2007)

Sorry, if I reduce or increase the sweep level both levels change accordingly and the 8dB difference remains .....

FWIW, if I use the SB Live I can't get the levels to match but if I use the Xfi, I can get the levels to match. I wante dto save the $80 and send the Xfi back but if it makes a huge difference I'll keep it.


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## brent_s (Feb 26, 2007)

As I said in your previous Vista thread, I had this problem as well. The REQW instructions say just go with it if you can't get the levels within the recommended range. In the end, my Vista based calibration and room measurements matched an XP based system that used the same SB Live external/mic/cables/etc. It has something to do with how Vista handles sound...you can't get the independent control of input/output levels like under XP....somehow MS considers this an improvement. 

-Brent


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## brucek (Apr 11, 2006)

Can you post a picture of the levels not matching? 

I'm still a bit confused by what you're saying. Once the output volume and sweep level are set, you adjust the input volume to match. Certainly, when you adjust the sweep level, both the output and input levels will change in unison because you have a short between line-out and line-in. But the Input volume adjusts the input independently.

Here's my card for example during the soundcard cal setup for levels.............

Are you not able to increase the input volume?









brucek


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## brent_s (Feb 26, 2007)

Bruce, if Cruz is having the same problem I had with setting up the Live External under Vista, he has no access to the Input Volume either via REQW or the Windows mixer. The soundcard calibration wizard tells the user to match the I/O levels within 3db (in your screenshot), but you can't do this with the Live External Vista drivers so you're stuck with a major difference in I/O levels...I think mine was around 10db, maybe a touch more.

Anyway, I found this in the "check levels - troubleshooting setting input volume" section of the online help and decided to procede despite the large difference in I/O levels. Seems to produce comparable results to the same Live/mic/cables/adapters used on an XP Pro machine that had I/O levels matched to around 1db at -12db per the wizard's instructions. 

Some soundcards do not provide an input volume control (e.g. some USB cards). As long as the signal RMS level is within the -30 to -12dB range when the speaker/subwoofer cal signal is playing everything should work OK. If the level is below -30dB try reducing the meter range to raise the level, but be careful not to reduce the range to the point the meter is overloaded. If the level is above -12dB try increasing the meter range to lower the level.

The problem is in the Live's Vista drivers. Creative hasn't given Vista access to the Input level. My onboard Realtek card allows access to the mic's input level, but of couse, it's not a true line input and is not recommended for REQW use. I was able to calibrate the Realtek card, but haven't tried measurements with it since the Live seems to be working with REQW properly, despite the lack of Input volume control and the large I/O level differences during soundcard calibration.

-Brent


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## brucek (Apr 11, 2006)

Thanks Brent - that's good info.

I had posted my response above at the same time as you, so I had missed your earlier caution on the Vista trouble.

Looks like Vista is a bit of a problem. I don't know if JohnM has done any work with it in regard to REW yet....

Anyway, I guess cruzmisl can carry on......

thanks,

brucek


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## cruzmisl (Jul 1, 2007)

This is with Sb live









This is with SB Live, notice the setting didn't change despite the fact the level is at 0.










This is with Xfi-no problems.....










Make any sense?? I guess it all has to do with the drivers. I think I'll keep the Xfi just because I know it works like it's supposed to. My SB Live measurements were OK too but my type A personality doesn't allow me to run the SB Live when I know the Xfi works


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## brent_s (Feb 26, 2007)

Assuming JohnM is the author of REQW, I doubt there's much he can do to help us with the SB Live External. The problem is with Creative's Drivers for the SB-Live-ext. They didn't even publish their first Vista driver until June...6 months after Vista was shipping. On their web site they advertise the Live Ext as "works with Vista", but they aren't real clear about what features don't actually work with Vista...like controlling the line input level. I can't get any of the bundled Creative software including the Creative Mixer Console to function under Vista...possibly user error on my part since the sparse documents Creative does provide seem to indicate at least some pieces should work. 

Fortunately for REQW users, it appears we can get by without the Input level control. It's only *really* needed for the loopback calibration, at least with the Radio Shack Meter as microphone. I suppose there could be microphone/mixer setups that don't have enough level control to get into a safe range for the Creative/Vista default setting.

Creative seems to be trying to point the blame at the changes MS made to the sound API in Vista. Nine months into Vista and Creative still doesn't offer full feature support on any of their products seems unbelievable for the apparent market leader and one time de facto standard setter. I'm not in favor of frivolous lawsuits, but this seems to be treading the thin line of a class action incompetence. 

*I just noticed Creative has released another set of drivers as of 8/23...haven't tried these yet, maybe there's been an improvement. 

-Brent


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## brucek (Apr 11, 2006)

Yeah, interesting.

I admit to knowing nothing of Vista yet, so this is new to me.

Certainly in XP, when a soundcard driver won't give REW access to its driver controls, it's quite easy to operate REW levels from the standard Windows playback and record Mixer. (i.e. adjusting the input volume via the Windows Mixer).

Does Vista not allow such intervention? or does it even still have a Mixer like XP?

brucek


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## cruzmisl (Jul 1, 2007)

Not really sure. I tried all areas of Vista with the sound controls and I couldn't get anywhere....


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## brent_s (Feb 26, 2007)

MS's new approach with Vista is the "mixer" controls master volume for each application. In other words, if you double click or right click the volume control icon and choose "mixer", you'll see a slider for each application currently running...not very helpful for REQW.

However, you can still access the individual devices exposed by the soundcard's drivers. Right clicking the volume control will let you choose "playback" or "record" devices...also accessible under control panel->sound. The Vista drivers for the SB Live External show the "line-in/mic-in" as one device even though they're two physcially separate jacks on the box.

The problem appears to be with either the max level allowed on the line-out or line-in on the SB Live...could either be caused by the Vista drivers or Vista itself. With the "raw" Vista devices for speaker out and line/mic-in at 100%, I'm getting a difference of 12db in the I/O level meters in REQW. The highest input level I can hit is -18db. Nearly identical to what Cruzmisl is showing in his screen captures.

Just for fun, I tried the loopback with the SB Live's mic jack. I get nearly a perfect I/O level match in REQW with both SB jacks at 100%. The calibration file shows a little earlier and more severe rolloff than the line input jack...for instance, the mic jack is -2.07 @ 10hz, the line in jack is -0.73.

Cruzmisl, if I were you, I'd save the $80. I think in essence, the Xfi has the same issues as the Live-External, you just see a better I/O level match due to some internal difference. You can get an accurate calibration using the Live's line input despite the largish -12db in I/O level. I just did a spreadsheet compare between my XP Pro calibration (I/O matched within 1db), my Vista calibration with the June Vista drivers, and my Vista calibration using the 8/23 drivers. Remember, same Live box and cables. The three calibration files look to track each other within .01 db from 10hz up. Below 10hz, the differences gets as large as .08db at some frequencies, still virtually identical for speaker measurements in my book.

Cruzmisl, I just took another look at your screen captures. Have you installed the Vista drivers from Creative? You're caps show "USB audio device" for your selected Output and Input device. That looks like the generic Vista USB drivers are being used. If you've installed the drivers, you should have devices with "Soundblaster Live..." in the name. It won't help your level matching issue, but I'd still think it's a better idea to use the mfg's drivers vs. generics.

-Brent


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## cruzmisl (Jul 1, 2007)

OK, loaded the Creative drivers for SB Live and got a 12dB disparity instead of 8 with the generic drivers Frustrated I started putzing around with the settings and it made no change. I then hit the CMMS button, which was off and the level didn't change. I turned it off and poof, it shot up to a 2dB difference. The calibration file also looks better. Someone else give it a try and see if it was a fluke. Make sure both knobs on the soundcard are maxed out.


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## JBravo (Jun 20, 2007)

*Re: using Vista & SB Live*

ok first off I'm wondering if I have all my settings under "Sound" setup right. I have under "Sound" under "Playback" Speakers is the only option I have enabled and set at 100 for level. Under "Recording" I have "Line In/Mic In" enabled and levels set at 100. Is there anything I should do to "Wave/Midi/CD" under "Recording"? I currently have it enabled and set at 100. I think this is correct.

ok so I got my soundcard calibrated and i've got the disparity that others have talked about when they use Vista & SB Live external. It was about 10 or 12 i believe and I had to have my sweep at -3 in order to get it as close as possible while running output volume at 1.

I test the cal file and everything checks out.

So Now I go to Check Levels. Output volume is 1.0 and muted. I adjust my Receiver's volume to -38, I leave sweep level at -3, Rat Shack meter says 75 ( bounces from 74-76, response is set to fast) all of this in turn allows me to get a input level of around -29/30 max. I am unable to adjust input volume as it is greyed out. But I check in the soundcard's settings and it is at 100. I assume this is ok since its the best i can get.

Onto Calibrate SPL. Everything checks out at 75.

Now ready to make measurements. When I go to check levels before making a measurement it says Level is Low. -32dB
I make the measurement and I get a message that the highest level in the measurement is -18dBFS, for greater accuracy increase the AV processor volume or the sweep level to raise the highest input level above -10dBFS. Note that after changing volume or measurement levels "Set Target Level" should be used before searching for peaks or adjusting filters to establish the correct reference level.

Ok so here is where I get lost as to how I should proceed.

I've attached a graph of the measurement, please let me know if I'm doing the right steps since this Vista stuff is driving my a little crazy. Any advice is greatly appreciated.


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## brucek (Apr 11, 2006)

Your sweep level is too high.

The Wave level should be at 1.000

The SPL meter should be set to slow.

Output Volume should not be muted.

Input level at -32dB is too low to take a proper measurement. Set the output level to -12dB and match that level at the input....

See below for an example of a Check Levels while it's running... note Output Device and Input Device information would be different on yours and should only be greyed out while Check Levels is running. If its greyed out all the time, you need to control from the Windows mixer.









brucek


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## JBravo (Jun 20, 2007)

brucek said:


> Your sweep level is too high.
> 
> The Wave level should be at 1.000
> 
> ...


Wave is at 1.000

Changed meter to slow

Output not muted

Lowered Output level to 12dB by setting Sweep to -12dB. This inturn lowered input level to about -32. Since Input Level is always greyed out I go to Windows Mixer and check level, its at 100 (max).

No matter what I do, I cannot get Input level to go any higher.


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## cruzmisl (Jul 1, 2007)

this nonsense you are dealing with is exactly why I bought an Xfi external..... I didn't know wether to curse Vista or Creative


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## brucek (Apr 11, 2006)

Well, if the input level of the soundcard is at its maximum, then the input level is determined by the actual SPL level in the room set by the receiver and the output level of the RadioShack SPL meter.

You can turn up the receiver so the RS meter reads 80dB (for example) and see if that helps, but beyond that I don't know what you can do other than try another soundcard...

brucek


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## JBravo (Jun 20, 2007)

yes I can turn up the receiver volume and the input will go up along with the dBs on the Rat Shack meter. Will this effect anything if the meter is reading >75 db? Say 85db? I plan on using a FBQ 2496 also so I didn't know if that would effect anything in that regards also.

I haven't been able to find a XFi external around here at the local Best Buy or Circuit City or Fry's Electronics.

I did find a EMU 0202 usb sound card but its $150. And Creative seems to keep the EMU series a top priority when it comes to updating drivers with Vista


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## JBravo (Jun 20, 2007)

cruzmisl said:


> this nonsense you are dealing with is exactly why I bought an Xfi external..... I didn't know wether to curse Vista or Creative


cruz,

which soundcard did you get exactly?

this thing?


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## brucek (Apr 11, 2006)

> Will this effect anything if the meter is reading >75 db? Say 85db?


No, it will simply mean you setup REW to take a measure at 85dB instead of 75dB. 

You have to realize though, that the lower the scale you use with the RS meter (i.e 70 as opposed to 80 on the big wheel), changes the output voltage level for a given SPL level. 

So, it's smart to try and keep lots of headroom for the meter needle in case you have some large peaks that might 'peg' the needle (which would clip the output signal). On the 80 scale, a reading of 85dB is almost full scale already. This might prompt you to dial up to 90 on the wheel. Oops, right back where you started with a low level. Better to see if you can get a decent input level by setting REW to test a target of 80dB and use the 80dB on the RS meter wheel...

brucek


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## JBravo (Jun 20, 2007)

Bruce, What do I need to chage in REW to test at 80dB? Do i just change the calibrate spl to 80 and then make sure the meter dial is on 80 still?


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## brucek (Apr 11, 2006)

Yep, and set the Target Level to 80dB................


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## JBravo (Jun 20, 2007)

with 80 dB ref setup with receiver and spl calibrated to 80 dB Dial set to 80 and target set to 80 dB this is what I've got:


















i notice that when i leave everything as described above but click the dial down to 70 on the RS meter i can get the Input and Output just about even at -12. Would this be a better route to go?


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## brucek (Apr 11, 2006)

Well, with the dial at 70, then the meter needle pegs at +76dB. Your highest level in your graph is about +86dB. So your meter is outputing a clipped signal full of distortion. 

So, no I wouldn't do this. 

If you're getting -23dB input level as you show in your picture above, while using the 80 db on the dial of the RS meter, it's gonna have to be OK.....

brucek


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## JBravo (Jun 20, 2007)

thanks for your help bruce!

Now i get to start figuring out what my graphs mean and start messing with the fbq 2496


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## cruzmisl (Jul 1, 2007)

Buknakyd said:


> cruz,
> 
> which soundcard did you get exactly?
> 
> this thing?


Yes, I got it from Fry's online for $20 after rebates. Rebate is still valid. Strike while the iron is hot.......


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## cburbs (Mar 27, 2007)

I am using Vista and the Soundblaster MP3+ and I get the following cal file - does this look ok? I have the same issue when setting up - reference the second pic for my setup info when calibrating the soundcard.


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## brucek (Apr 11, 2006)

Yeah, it's good. You actually have a very good low frequency response with that card (as evidenced by the squiggles between 0Hz-10hz). To correct this squiggle problem in the final soundcard cal file, you need to extend the Impulse Response window so that more of the response is included. Extend it until it's a bit smoother and then save the file.

To do this, run the soundcard cal routine and get to the spot where you are about to click Finish. Don't click Finish, instead click the IR Windows ICON in the upper right corner of the REW screen. A popup will arise and it will show the pre-window as 125msecs and the post window as 500msec. Extend the post window longer, and as you do, you'll see the Frequency Resolution result lowering. Change the window to something like 1000msec and click Apply Windows while watching your squiggles. See how it's smoother now? Hit Finish on the soundcard cal routine and save the file. Your measurements will be more accurate down lower now.....

Don't extend the window too far or you'll begin to pick up noise in the soundcard response. Watch for this. In fact, extend the window way out to maybe 1500msec and see if noise begins to appear in the response. Anyway, somewhere around 750-1000msec should be fine...

brucek


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## cburbs (Mar 27, 2007)

Ok so in order original scal, 750 scal, 1000scal, and 1500socal, and now 1250 so cal. So which one should I use? again thanks for all of your input on this forum - it is great that people can share there knowledge with each other on different HT stuff.


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## brucek (Apr 11, 2006)

You're starting to show some noise in the signal as you can see. Personally I would first attempt a few soundcard calibrations at a few different Check Level settings and try and clean the signal up first. I find my card gives the best response when the routine shows about a 3dB headroom.

Then apply the longer impulse window to the result once it's cleaned up a bit. See how your signal is starting to want to oscillate evidenced by the thicker line above 10KHz....

Test different input volumes until you get the best response....

brucek


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