# How to correctly set filters on 1124...



## Digital_Chris (Apr 7, 2011)

First off, I'm going to apologize in case this has been covered before, but I did a search on the forum, on YouTube, and in the manual and it wasn't very specific on how to actually set and the store filters.

As far as I have learned, I will set the 1124 into parametric equalization mode, click the "filter" button and select whatever filter number I want. Once that is selected, I go to the "frequency" button and select my target frequency, followed by additional db on the 1/60 octave button (50hz +7 = 57hz?) and then select the target gain (-10 db) and then select "store". After I hit "store", the red light remains blinking and everything seems okay but once I turned 1124 off and then back on, the filter(s) have disappeared.

The other odd thing is, let's say I want to set a 10 dB cut at 57 Hz, I seem to set that correctly in the BFD and what actually ends up happening is my whole response from roughly 10 Hz to a couple hundred hertz gets cut by about 10 dB and not just the 58hz peak I was looking at.

What might I be doing wrong?


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## JohnM (Apr 11, 2006)

You have to press store twice to actually store. The first press starts the preset number flashing, to allow you to choose a different preset if you wanted to do that, the second press saves to the selected preset.

The 'fine' filter frequency adjustments are in 1/60th of an octave, use the frequency chart in the Appendix of the manual to see what values you need (57Hz would be 50 and +10/60th, for example). 

You didn't mention setting the filter bandwidth, don't forget to do that - sounds like you may have set a very broad bandwidth.


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## Digital_Chris (Apr 7, 2011)

Ahh yes, that is exactly what I forgot, the bandwidth!! I will also have a look over that chart you mentioned.

I thought I hit the store button twice once already to try that, but I thought it was still blinking. I will definitely play around with it a little more.

Thank you for your reply John


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## Digital_Chris (Apr 7, 2011)

Ok, saw the frequency chart, that's all set now. What about the bandwidth, I'm not sure what those numbers mean and how low I should go. Any tips on that? Lets say that my peak starts inclining at 38hz, peaks at 57hz and ends at 72hz, how do I know what "bandwidth" to set that filter at?


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

Perhaps you’re not aware, but you can tweak BFD settings on the screen. With your frequency response graph displayed, open the EQ panel. Any EQ adjustments you make in the EQ panel, REW will show the predicted effect – i.e., change to response. When you’re happy with the predicted response, load the filter settings REW shows into the equalizer, and then take a new measurement.

Regards, 
Wayne


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## Digital_Chris (Apr 7, 2011)

Oooh, I didn't know about that.. neat 

Also, it shows my "targe" spl of 75db which is where I set my levels in REW but noticed that 90% of my response graph is 5+db below target, what could be this reason?


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

It’s not unusual for a sweep to end up higher or lower than the test tone used to pre-set the levels. It’s no big deal, just re-adjust the Target to a midway point between the peaks and depressions before equalizing. :T

Regards, 
Wayne


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## Digital_Chris (Apr 7, 2011)

Great, thanks Wayne : )


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