# need some help calibrating



## Guest (Dec 3, 2006)

OK. So when i laund REQW, it tells me it's loaded the RS SPL meter calibration file i donwloaded: fine. 

So i've connected the RS SPL meter to the line input, i've told it to record without monitoring.

So then i launch REQW, and try running calibration wizards.

1. I do the set input volume, which works fine, or so it seems.

2. I try the 'calibrate' button, and the readings on the SPL meter are @ around 100db... since the scrollable menu that i'm told to match to what my SPL meter shows only goes to 90db, I'm thinking something is wrong.

Should I simply turn down the master volume control on my computer? wouldn't that be screwing with the calibration?

I tried turning the system volume down to 1/2, but then the 'set input volume' wouldn't work. 
So i turned the system volume up to about 3/4, and it did work. Then i used the calibrate button, and had to set it to 88db.

Something just doesn't seem or feel right here.

Any help would be appreciated. :scratchhead:


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## brucek (Apr 11, 2006)

Hopefully you're using stereo adapters on your line-in and line-out jacks of the soundcard, and only using one channel of those adapters (usually the right).

Ensure the sub is on and the rest of your speakers disconnected (or external power amps off if you have them). 

Have the normal sub crossover set (80Hz for example).

Have your receiver in STEREO mode with speakers to small.

First you should *SET MEASUREMENT LEVEL* and adjust your receiver volume to 75dBSPL on the RS meter in your listening position. Now we know the room is at 75dBSPL. Output done.....

Next *SET INPUT VOLUME.* Input done.

Next *CALIBRATE* the REW SPL meter to the RS meter. Now both meters match.

The next one time event is to put a short between the line-in and line-out and *Measure Soundcard Response* to create soundcard calibration file and save it, so it loads every time hence.

Put your normal cables back on.

Now set the *TARGET LEVEL.*

Then *AUTOMATIC MEASURE* to 200hz. Use horizontal axis of 15Hz to 200Hz and vertical axis of 45dB to 105dB.

brucek


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## Guest (Dec 3, 2006)

actually, for testing my sub, i was running the white RCA straight to the subwoofer, bypassing the receiver completely. I will follow your method next time.

Question about your terminology there:
what do you mean by a 'short' between the line-in and line-out on my sound card?


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## brucek (Apr 11, 2006)

> what do you mean by a 'short' between the line-in and line-out on my sound card?


A short cable with male 1/8" stereo plugs on either end. The soundcard has stereo jacks so you need a stereo cable. Only one channel will be used, but you still need the right connection to make it work.

This cable shorts (connects) line-out to line-in...











Or you can short the cable you are connecting to your receiver to the cable you're using for your meter with an adapter.

brucek


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## Guest (Dec 4, 2006)

uhg, another cable to buy! ah well...

as is, i've got two 1/8" stereo to L/R RCA 'Y' cables, one in the Line In, and another in the same jack that i plug my headphones into, and an RCA running to my RS meter, and the other to the reciever or sub.

So, i just need to get a 1/8" stereo to 1/8" stereo cable now, eh?


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## brucek (Apr 11, 2006)

> So, i just need to get a 1/8" stereo to 1/8" stereo cable now, eh?


Yep, or simply use a female to female RCA adapter to make the short with the cables you have.

I can't imagine you haven't got the 1/8" cable. I don't know a piece of equipment I've purchased that didn't come with one that now sits in a drawer...

brucek


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## Guest (Dec 4, 2006)

i purchased my receiver from a friend, in a horse-trade, heh ... didnt come with a 'short' cable... but yeah, I definately could use one of the female-femaile RCA couplers i've got to do that... sweet.

For the sake of simplicity, can I do all of this but with the speaker-out RCA going directly to my sub?


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## brucek (Apr 11, 2006)

> For the sake of simplicity, can I do all of this but with the speaker-out RCA going directly to my sub?


Speaker out? Do you mean line-out? If so, I recommend highly that you feed the receiver (AUX or CD) input. Then you will engage the crossover. It will give a better idea about filtering or positioning if that's the purpose of the exercise. 

You will also have the receivers volume control to set the level with. 

You'll also get a better idea of how the mains integrate with the sub around the crossover once you get to that step of the process.

brucek


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## Guest (Dec 4, 2006)

Sounds good.

I'll give it a try ASAP and post here with any other questions / concerns.


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## Guest (Dec 4, 2006)

arhg.
Ok, i've got it all hooked up the way you suggested. I did the Set Measurement Level just fine... but when i go to set input level, it gives me the "input volume control is at it's maximum" message ' the wizard was not able to set the input signal RMS level to -18db, even with the volume control at it's maximum setting. If the signal is above -24db it will probably be OK and the correct input has been selected."

So, in order to 'set the input volume' i had to lower the RS SPL dial a notch, down to "70" ... 

so onto the next step i go.

i hit the calibrate button, and it tells me to match the number in the box with the one shon on the RS meter readout (the one in big numbers at the left of the screen) ... which i cannot do! the meter readout shows 96db or thereabouts, so i had to go change the RS meter dial (again) back to 80db setting. Tried it again, and I was able to match the numbers.
Is this correct? *confused*


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## Guest (Dec 4, 2006)

While i await your answers on the above, i've moved onto the Soundcard calibration ...
is the value in the up-down clicky box supposed to match the value displayed in the 'db SPL' box at the left? (where your RS meter is normally showing readins) ... to match, mine needs to be clicked up to -28, does that sound normal?

Thanks again!


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## Guest (Dec 4, 2006)

OK, i think i'm going insance. I switched back to my 'normal' cable setup, and now I cant send anything from my computer to the receiver and hear it.


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## brucek (Apr 11, 2006)

> but when i go to set input level, it gives me the "input volume control is at it's maximum" message


When you see this, it means there is not enough level from the Radio Shack SPL meter feeding the line-in connector. See below.



> So, in order to 'set the input volume' i had to lower the RS SPL dial a notch, down to "70" ...


Yes, correct. The meter should be dialed and left at 70 because you're going to be calibrating to 75dB...



> hit the calibrate button, and it tells me to match the number in the box with the one shon on the RS meter readout (the one in big numbers at the left of the screen) ... which i cannot do!


I'm a little confused about that? You set the Measurement level so the the RS Meter shows 75dB and then you set the input level. So now you want to match that 75dB actual reading from the RS meter to the REW meter. So set the REW meter to 75dB.... Now the RS meter reads the same as the REW meter. Leave the RS meter at 70 on the dial for the entire exercise. Don't move it or your receiver master volume once set. If you do, simply start over....



> is the value in the up-down clicky box supposed to match the value displayed in the 'db SPL' box at the left?


Sorry, don't understand this. Once your levels are set and you attach the loopback cabel, pull down the Soundcard selection and execute the Soundcard measurement routine.

brucek


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## Guest (Dec 4, 2006)

OK, starting again I guess. I'll post an update soon.


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## brucek (Apr 11, 2006)

Oops, just re-read my post and realized I better stop relying on my bad memory. I don't mean to say set the RS meter dial at 70, I do mean to say set it at 80 on the dial and set the calibration to 75dB in REW. This then gives you lots of headroom from 75dB so the RS meter needle won't peg when running measurements.

Sorry, for the mixup. I use an ECM8000 microphone and tend to forget how to use the RS meter.

Anyway, there's no reason for you not to manually turn up the input volume in REW if the automatic setting doesn't work for you.

brucek


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## Guest (Dec 4, 2006)

while i re-calibrate with the 80 RS meter dial setting, can you tell me how to set 
"Use horizontal axis of 15Hz to 200Hz and vertical axis of 45dB to 105dB." ?
I tried zooming in, but that only half-*** works


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## Guest (Dec 4, 2006)

now i'm totally confused.
On the back of my audigy, I think i had my receiver connected to the wrong jack?
I think i had it connected to the Speaker jack, when it should have been connected to the Line Out jack? I'm totally NOT sure which jack that is, and on top of that, the only option under SB Audigy (which is just above the set measurement level button in REQE) is SPEAKER ... no Line Out or anything else listed there at all. 

Are Speaker and Line Out the same thing?

EDIT for picture...
http://www.imagemonster.net/is.php?i=15039&img=9759audigy.jpg


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## Guest (Dec 4, 2006)

I really should PS the above post.
When i connect the receivers 1/8 jack to the 'Line Out' in that photo i get nothing. When i connect it to the 'speaker' in that photo, i get sound.

By my logic, the latter is correct. Yes / no?

the REQW always uses the term Line Out, and specifically says that "output volume should not effect line out but may effect headphone or speaker outputs"

Unless i'm mistaken, the SB Audigy does not have a Line Out jack.


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## Guest (Dec 4, 2006)

Is there any way to set everything to the default settings in REQW? 
This thing seems to be getting totally FUBAR'd with all the messing around i've done today.


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## Guest (Dec 5, 2006)

Can i just ask one basic question? 
I'd love to know exactly why when i click 'SET MEASUREMENT LEVEL' and do what i'm told to, and then click 'SET INPUT LEVEL' the set input level fails?

If I increase any of the other volume controls, i'm falsley inflating the output compared to the just calibrated setting, making the whole calibration incorrect.


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## Guest (Dec 5, 2006)

another real basic quandry: i've got the mic plugged in and it's sitting at my listening position. With no noise in the room it's outputting a measurement of 68db or more.
Is it just me, or is that all out of whack? when the kids run upstairs, it spikes to over 80db ... just seems it's too sensitive or something.

Maybe i'm just totally frustrated because i'm getting confused and not getting anywhere, i don't know 

Thank you for all the time you've put into this thread regardless.


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## brucek (Apr 11, 2006)

> Use horizontal axis of 15Hz to 200Hz and vertical axis of 45dB to 105dB


Click the icon "set graph axis extends" located at the bottom right hand side of the graph and set the axis. It will remember the values the next time you click it.



> I think i had it connected to the Speaker jack, when it should have been connected to the Line Out jack? I'm totally NOT sure which jack that is, and on top of that, the only option under SB Audigy


Just look in your manual or download the manual if you don't have one. There will be a line-out. I don't know if they call it speaker. I don't know your model of Audigy - there are many types.



> and on top of that, the only option under SB Audigy (which is just above the set measurement level button in REQE) is SPEAKER ... no Line Out or anything else listed there at all.


REW uses the term speaker out, select that one.



> When i connect the receivers 1/8 jack to the 'Line Out' in that photo i get nothing.


You should. Ensure Line-out isn't muted in your control panel mixer.



> Is there any way to set everything to the default settings in REQW?


All the level settings are on the screen for you to set as you wish. There is no real default.

brucek


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## Guest (Dec 5, 2006)

OK, i've got the correct graph axis etc. set at least...



> Quote:
> When i connect the receivers 1/8 jack to the 'Line Out' in that photo i get nothing.
> You should. Ensure Line-out isn't muted in your control panel mixer.


In regards to this... there is no Line-Out in my control panel mixer. 
Could it perhaps be 'Auxilary' ?


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## Guest (Dec 5, 2006)

I've verified via online download of Audigy manual that i've got the correct connections. The one I use for my headphones IS the Line-Out, it supports headphones.

At least, next time I start this again, I know i've got the correct connections made.


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## brucek (Apr 11, 2006)

> At least, next time I start this again, I know i've got the correct connections made.


OK, great.



> In regards to this... there is no Line-Out in my control panel mixer.


Yeah Ok, I should have said be sure that WAVE was not muted. 

I just looked at mine and here's a pic of the Recording Mixer and Playback Mixer and what controls the levels in REW and what should ne unmuted.









brucek


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## Guest (Dec 5, 2006)

I'm not gonna mess with this tonight. Hockey game... and had a real bad morning @ work, so i wasnt in a great mood when i started this, this afternoon. Then i had trouble with it... man, i was just about ready to throw the RS SPL meter out a window... not that I ever would. 

Would it be easier to 'walk' me through this over the phone? I only ask because i've got unlimited long distance in North America.


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## Guest (Dec 5, 2006)

One more thing. In my mixer control panel thingy, which looks like yers, Line In is under playback, not recording. Strange....

anyhow, i'll give it another shot sometime tomorrow, maybe in the early evening.


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## brucek (Apr 11, 2006)

> Line In is under playback, not recording. Strange....


That's normal. I think it's actually listed under both in mine.

Once you've played around with this for a bit, you'll find it easy...

brucek


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## Guest (Dec 6, 2006)

BruceK, i'm having trouble understanding what i need to do while setting the 'Input Volume'. It gives me the message shown in the following linked picture:
http://www.imagemonster.net/is.php?i=15052&img=reqw_error_when.jpg

What am i supposed to do here? 
my receiver is at my normal listening volume for LOTR type movies, which is where I want it for the tests, and happens to be where it reads the targeted 75db in the first Set Measurement Level calibration.

Am I correct in saying that if i increase my system volume, the Set Measurement Level test is for naught, because the Input Volume calibration is based on the setting (on the RS meter) used in the Set Measurement test?


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## Guest (Dec 6, 2006)

I totally made a bad assumption!
When doing the original Set Measurement Level, i was reading the amount shown in the big black letters at the left of the REQW screen, assuming that this was a straight reading from the RS meter... which it obviously wasnt.

Now then! ... i went and looked at the SPL meter, and did both the set measurement level, and set input volume tests correctly (i hope!) and i'll move onto the next ones here shortly. 

Will update if need be 

thanks again, man!


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## Guest (Dec 6, 2006)

Ok, i'm onto the soundcard calibration... the explanation built into REQW isnt exactly clear... see image:
http://www.imagemonster.net/is.php?i=15053&img=reqw_soundcard_.jpg

Am i supposed to match the number in the 'Soundcard Measurement Inp' window with the big black 7.3 on the left side there?

Think i'm almost ready to (accurately) measure my little subwoofer! *cheer*


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## brucek (Apr 11, 2006)

> Am i supposed to match the number in the 'Soundcard Measurement Inp' window with the big black 7.3 on the left side there


No, you don't do anything here other than hit CONTINUE and REW takes care of doing the test.

BTW, have you read the very excellent REW HELP FILES? They explain all this very simply. 

brucek


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## Guest (Dec 6, 2006)

OK bruce, we're measuring!

only one questions for you though  no error message this time... heh...

Why do you say to measure to 200hz? isn't there a crossover in the AV processor, even with the mains set to small, that's going to throw all the stuff over say 120hz to the mains?

Anyhow, i'll post a graph measuring from 25hz to 134hz, as above that there's no point.

http://www.imagemonster.net/is.php?i=15054&img=first_correctly.jpg

The **** <img> tags arent working.


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

Here it is:










Regards,
Wayne


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## brucek (Apr 11, 2006)

> Anyhow, i'll post a graph measuring from 25hz to 134hz, as above that there's no point.


Measure from 10Hz to 200Hz. The automatic sweep starts at DC and then ends an octave above 200Hz. This ensures the response is accurately captured throughout the requested range.

Use horizontal axis from 15Hz to 200Hz and vertical axis from 45dB to 105dB.

Set your graph to LOG and not LIN.

brucek


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## Guest (Dec 6, 2006)

hrm, i thought i had the axis set correctly.
and i swear i thought i had it set to log


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