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Please critique my graph

5K views 24 replies 3 participants last post by  Wayne A. Pflughaupt 
#1 · (Edited)
Okay I finally got my subs in decent locations and would like a critique of my flat response also I am looking for advice of where I may begin equalizing. I plan to use brucek's house curve recommendation once i get these results flat enough.

The graphs below are of both subs performing together. ME = Max Extension Mode while MO = Max Output Mode.
The first picture is my side sub in ME mode and my front sub in MO mode. Picture two is both subs in ME mode. Picture three and four are the subsequent Impulse graphs. Thanks!

test 1

test 2

 

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#7 ·

sorry man. the graphs are both subs running together.
So each trace is both subs running together, not each sub separately? :scratch:

So which one should I work with? Where both subs are in Max Extension mode or with one in ME and the other in Max Output?
Have no idea which is which, but I think I'd prefer the purple for movies and the green for music.

Regards,
Wayne
 
#9 · (Edited)
okay here is my corrected (equalized & flat) graph BEFORE adding the house curve. i performed 3 filters to get this result. Filter #1 @ 92 hz (+10db), Filter #2 @ 84 hz (-6db), Filter #3 @ 67 hz (-7db).

2 questions though:
  1. should I even be concerned with adding filters after 80hz which is my designated cross over?
  2. My target line (viewable on the graph is 75db). My curve is considerably above the target line. Shoud I still use this line as a basis for establishing my house curve? if so, how do I use REW's tools to create a house curve filter?

 

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#10 · (Edited)
Completed Hard Knee House Curve

Okay, I completed my first hard knee house curve. Thanks tremendously for Wayne's work. I am sure my first draft is missing the mark but I am determined!
You will find below:
  1. Hard Knee Curve which includes a trace of my dual subs as well as the correction (dotted lines)
  2. Filters
  3. Plots to attain my hard knee line
I am open to ANY advice I can get. Thanks!
Please note that I did not make any filter corrections beyond 70hz because Wayne's suggestions (or my interpretation of his suggestions) deem such modifications beyond 70hz immaterial.

**the 3rd filter BW/60 entry is 13 ...sorry for any confusion


 

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#12 ·
wayne i wondered about that too! after i put all my furniture back in place and tweaked the position of my subs a little for aesthetics the dip went away. i ran a test multiple times to be certain and it was sure enough gone. this mode stuff is way beyond my comprehension.

okay i will add a 85hz filter. question for you though. well first THANKS to you! that write up you did on a hard knee curve man is brilliant. it took a while for me to understand it but that is simply because of my learning disability. it is very well written though. question: even though i am plotting a 6db drop from 30hz to 80hz, the graph shows more of a 12db drop. i even checked the graph in your write up and although you went from 30hz to 90hz it was still somewhere around the ball park of 12db drop. how does it go from 6db to 12db?? this has me tremendously confused.
 
#14 ·

Thanks for the feedback on the article, Will! I try to write this stuff so that it isn't lost on novices; nice to hear I was successful. :T Your hard knee graph looks great, assuming you can get it to look like that after EQing.

even though i am plotting a 6db drop from 30hz to 80hz, the graph shows more of a 12db drop. i even checked the graph in your write up and although you went from 30hz to 90hz it was still somewhere around the ball park of 12db drop. how does it go from 6db to 12db?? this has me tremendously confused
.
Well, you're already getting a certainly amount of drop at 90 Hz because of the crossover. The house curve slope is added on top of that. You want to keep your eye on the shelving frequency and below, not the top end of the sub range. With the slope added, the Target Curve should rise in your case 6 dB. Looks like yours went from 74 dB to 80, so you're on track.

how is this? i also disabled the 1/6 smoothing so you could see some of that 90hz dip you spoke about
The main reason to use smoothing would be to prevent REW's auto EQ function from going overboard on the equalization, or to help keep people who are manually equalizing from doing the same thing. You don't seem inclined to do that, so go ahead and stick with the unsmoothed graphs.

Regards,
Wayne
 
#17 · (Edited)
well sir, i require your help again. its seems like all the good hard work i did is wiped out. one of my subs was configured improperly, and, according to the manual, it might damage my sub. i had a port plug inserted (maximum extension mode) however the switch on the back of the sub was set for 'no port plugged' (maximum output mode). i set the switch to the proper setting and my graph went to the pits. there is some crazy mode in my room that was fine with an improperly configured sub but has a real attitude at a properly configured one. i moved the subs 2 miles around that room and finally found a decent setup. i created new filters and everything looked pretty good.


AND THEN I ADDED THE MAINS TO THE EQUATION :yikes:



That didn't look good so i pushed the mains back toward the back wall some to see if that would help



i'm stumped bro. with the mains added to the equation, things dont look so good anymore. any suggestions where i should start?? :reading:
 

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#22 ·
brucek can you elaborate more on this work around? i have placed the distance of my speakers and subs in the configuration menu of the receiver already. for the dual subs i added the distances and divided by 2 to get the average (not certain if this is proper or not).

also i would love to hear your comments on my last posted graphs. thanks!
 
#23 ·
can you elaborate more on this work around?
It's not really a workaround. The digital delay in the receiver basically offers a pure phase delay, just as a phase control attempts to do. The phase control (if done correctly) is an all pass filter that acts as a delay that remains linear over its range. So, the time delay and phase control are a near proxy for each other.

for the dual subs i added the distances and divided by 2 to get the average (not certain if this is proper or not).
It's not proper, but then there is no proper solution for two or more subs that aren't co-located. That's why you should co-locate them (or use a separate phase control on each).

hear your comments on my last posted graphs
They look fine to me. Once you've taken care of all the obvious peaks and dips (as you have), then it's just individual taste...

brucek
 
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