# PEQ filter suggestion



## nickwin (Dec 10, 2007)

Im looking for advise on what PEQ filter I need to flatten out the response of my DIY sealed Dayton UM18. I thought ARC was going to take care of it but it did exactly what it is suppose to do and it flattened out the peaks but didn't really change the response of the sub (which I want in this case). I have a MiniDSP hooked up so I can apply PEQ, the only thing is I have no experience with PEQ so Im not sure exactly what filter to use. Any suggestions? Im thinking center 60hz, -6 - 10db, 80hz width? 

This graph is from the MLP post ARC but I would apply this filter and then re run arc. 

Thanks!


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## RTS100x5 (Sep 12, 2009)

I would start by purchasing a calibrated mic , like the MiniDSP , from Parts Express ($85).. The download REW (free from Home Theater Shack) and you'll get to measure your subs response - then REW will generate a correction filter for you that can be saved as a file and imported into MiniDSP / PEQ ..... this will save you from alot of guess work... Easy instructions on this procedure are readily available...


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## nickwin (Dec 10, 2007)

RTS100x5 said:


> I would start by purchasing a calibrated mic , like the MiniDSP , from Parts Express ($85).. The download REW (free from Home Theater Shack) and you'll get to measure your subs response - then REW will generate a correction filter for you that can be saved as a file and imported into MiniDSP / PEQ ..... this will save you from alot of guess work... Easy instructions on this procedure are readily available...


Hi, thanks for the suggestion! I actually already have a calibrated mic, MiniDSP and REW, I'm just not familiar with the generated EQ filter function or PEQ's in general. The attached pic is my in room response at the MLP. I thought since its basically a nice symmetrical hump maybe someone could just tell me the filter needed just by looking at it but maybe trial and error is the only way.

Can anyone recommend a starting point? Again, ARC will take care of all the peaks, I'm just trying too flatten out the broad hump at 60hz.


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

I’d recommend a filter @ 63 Hz 2/3-octave (2.1Q) bandwidth. I’m not familiar with Hz as bandwidth, so you’ll have to figure out the conversion. I wouldn’t cut more than about 5 dB, or you’ll probably end up with a big peak at ~ 40 Hz.

Regards, 
Wayne


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## nickwin (Dec 10, 2007)

Wayne A. Pflughaupt said:


> I’d recommend a filter @ 63 Hz 2/3-octave (2.1Q) bandwidth. I’m not familiar with Hz as bandwidth, so you’ll have to figure out the conversion. I wouldn’t cut more than about 5 dB, or you’ll probably end up with a big peak at ~ 40 Hz.
> 
> Regards,
> Wayne


Thanks Wayne! Like I said, Im pretty clueless in regard to parametric EQ, Q is indeed the metric the MiniDSP uses. 

Would you make it that narrow even if I was going to run my auto EQ (Anthem ARC) over top of this? I started to play around with it this evening and I was thinking more like 1Q -9db @~60hz. Im wondering why you suggest a narrower filter with less cut? Is -9db too aggressive? 

Here is the response at the MLP with no EQ applied.

Thanks for the help!


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## nickwin (Dec 10, 2007)

Here is 60hz, 1Q, -9db with auto EQ off. I kind of thought I was on the right track but Im still learning. Am I cutting to much into the deep bass with this filter?


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

That’s actually the curve I was looking for after EQ. That’s about as good as you’re going to get. It’s a severe cut, but your driver looks pretty substantial. If you’re room isn’t too big it should work fine.

Regards, 
Wayne


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## fusseli (May 1, 2007)

Another starting point I would suggest for that sub would be a Linkwitz Transform (LT), or a low-shelf filter (i.e. LS12 or LS6). You would put the cutoff at say 30 Hz and the filter would lift everything below that by a couple dB to bring the sub-bass up in magnitude so you have a flatter overall trend rather than the hump trend. This is popular with sealed subs, but it requires a lot of sub driver capability and amplifier power. You could apply the filter before or after your automatic ARC setup and go with the result you prefer.


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