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View Full Version : Graph reading from all 3 subs


Nick Chapman
01-05-2008, 07:48 AM
Here's a reading I took last night. Running all 3 subs. Still not exactly what I want, but decent. Gets down to about 12hz before it drops off pretty drastically. Still have a bit of fine tuning to do, but it sounds amazing! :D

http://www.dfwstangs.net/coppermine/albums/userpics/10253/all_3_subs.jpg

fordracing19
01-05-2008, 10:16 AM
How are you graphing that?

Nick Chapman
01-05-2008, 10:32 AM
How are you graphing that?


Program called REW on the puter. Set a mic up at the listening position and conect it to the puters sound card. REW plays a test tone, and puts it into a graph like this.
REW will then talk to the EQ in my audio rack, and make any adjustments that I request.

Pretty cool system to flatten out the subs frequency's.

fordracing19
01-05-2008, 11:27 AM
Program called REW on the puter. Set a mic up at the listening position and conect it to the puters sound card. REW plays a test tone, and puts it into a graph like this.
REW will then talk to the EQ in my audio rack, and make any adjustments that I request.

Pretty cool system to flatten out the subs frequency's.
Did you down load it? Link?

Nick Chapman
01-05-2008, 11:27 AM
Did you down load it? Link?
http://www.hometheatershack.com/roomeq/

my fear
01-05-2008, 11:42 AM
o damn at first i thought this was in a car lmao, i just remembered you got subs for your badass surround sound. thats really good.

line-em-up
01-05-2008, 11:57 AM
How does the program compensate for inaccuracies in the mic or sound card?

Nick Chapman
01-05-2008, 12:40 PM
How does the program compensate for inaccuracies in the mic or sound card?


It calibrates each of them.

line-em-up
01-05-2008, 01:10 PM
It calibrates each of them.

But, it's got to use one something as its reference to begin. How does it know if that reference is accurate? Did you get a professional grade mic?

fordracing19
01-05-2008, 01:19 PM
http://www.hometheatershack.com/roomeq/
I downloaded it but I think this is over my head. I do have the ratshack analog meter. So I need a soundcard other than my laptop? :confused: I want to graph my SvS sub.

line-em-up
01-05-2008, 01:25 PM
But, it's got to use one something as its reference to begin. How does it know if that reference is accurate? Did you get a professional grade mic?

I was checking out their site. They metion in one of the forums how they have calibration curves built into the program for some common mics.

Re: REW [Room EQ Wizard] Tips

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Correction Value Files (*.cal) and REW

All microphones are not created equal. Unless you are willing to spend several hundred dollars on a high quality mic, you will not have a flat frequency response measurement from your mic. Nearly all inexpensive mics need correction values applied to them to get the frequency response to flat.

For example, most of us using the BFD will simply use the mic in our Radio Shack SPL Meter. That mic is generally down 27db at 10hz. In other words, when you take a measurement of the frequency response of your sub, you will need to add 27db to the reading at 10hz. For more information on the RS Correction Values see this thread.

Correction values are input into the REW program via a *.cal file. This is a text file built usually in Notepad and saved with the .cal extension.

Once you have acquired the *.cal file you are going to use, you will load it into REW as follows:

Nick Chapman
01-06-2008, 06:15 AM
I was checking out their site. They metion in one of the forums how they have calibration curves built into the program for some common mics.

Re: REW [Room EQ Wizard] Tips

--------------------------------------------------------------------------------


Correction Value Files (*.cal) and REW

All microphones are not created equal. Unless you are willing to spend several hundred dollars on a high quality mic, you will not have a flat frequency response measurement from your mic. Nearly all inexpensive mics need correction values applied to them to get the frequency response to flat.

For example, most of us using the BFD will simply use the mic in our Radio Shack SPL Meter. That mic is generally down 27db at 10hz. In other words, when you take a measurement of the frequency response of your sub, you will need to add 27db to the reading at 10hz. For more information on the RS Correction Values see this thread.

Correction values are input into the REW program via a *.cal file. This is a text file built usually in Notepad and saved with the .cal extension.

Once you have acquired the *.cal file you are going to use, you will load it into REW as follows:

Yeah, they have a calibration system in place to set up for different model mic's. Someone has already done all of the hard work :D