# Calibrated first time with 1124



## ccap (Feb 7, 2010)

Hi All,
Here are a couple of graphs of my theater subs. The first is without calibration and the second is calibrated on the 32hz range.

I want to make sure that I am doing this correctly. 

Couple of questions...

1. How do you calibrate another frequency once one is calibrated. I tried to work on the 60hz freq and the bandwidth, gain and fine tune ll seem to follow, meaning I cannot set separate settings for each freq.

2. Can I get some explanation on bandwith and how it affects the freq you are working on and also fine tune. What does that do in connection with the freq you are working on. 

For the calibration of the 32hz graph, the setting I have on the eq are, freq 32, bandwith 30, gain 8 and fine tune 0.

Thank you!!


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## JohnM (Apr 11, 2006)

I guess you are using a BFD DSP1124P? Frequencies on the BFD are defined by "coarse" and "fine" settings, the coarse setting is the nearest 1/3 octave centre frequency and the fine is an offset in approx 1/20th octave steps. The easiest way to see the effect of your EQ settings is to use the REW EQ window and look at the "Filters" trace to see the combined effect of any filters you have set up. If you tick the "Show each filter" box in the graph controls you can also see the contribution of each individual filter. Bear in mind that whatever boost filters you apply reduce your headroom at those frequencies correspondingly.


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## ccap (Feb 7, 2010)

Thank you for the reply. Not being well versed in EQing. I tried using the eq in rew and was a bit confused how to use the settings. In addition, I am trying to figure out how to set different freq in the EQ. Does anyone know how to do this.

Also I am looking for comments on the graph. Is it where it should be and I just need to adjust the 60hz range?
Thank you


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

Looks like about a 5-6 dB dip there at 60 Hz. You might try adding a filter there and see if it makes an audible difference.

Regards,
Wayne


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## ccap (Feb 7, 2010)

Thanks Wayne,

I was hoping for a Wayne response. How do you think the graph looks after the 32hz adjustment? 
As in the first post, I can't understand how to adjust another filter without affecting the pevious filter you just adjusted. So for example I adjusted the 32hz with gain 8 and BW30, now I want adjust the 60hz range so I select the frequency then adj gain and BW and save, now it looks like I readjusted the 32hz. Is this the correct way of doing this?

Thanks
Chris


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

Unlike the 32 Hz filter, the 60 Hz filter will be fairly narrow, so if you get it set right you can hopefully minimize its “spilling over” to the other filter. But yeah, it’s common for the filters to overlap if they are close together. You can play with the two filter’s parameters in REW until you get the response you’re looking for on the screen, then apply with filters to the BFD and take a new measurement. 

Regards,
Wayne


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