[thebuffman]

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

 

[Wayne A. Pflughaupt]

Please re-scale your frequency response graphs for a 15-200 Hz horizontal and 45-105 dB vertical axis. You can do that by clicking on the "Graph Limits" icon in the upper right corner.

Regards,
Wayne

 

[thebuffman]

Here is a graph with both graphs combined.

 

[thebuffman]

Please re-scale your frequency response graphs for a 15-200 Hz horizontal and 45-105 dB vertical axis. You can do that by clicking on the "Graph Limits" icon in the upper right corner.

Regards,
Wayne

wayne i must be missing something because this is the first thing that i did. i went back to double check and it is set at those specifications.

edit: sorry...i never clicked "apply" with the graph selected

 

[Wayne A. Pflughaupt]

Have no idea what "ME" or "MO" mode is, but the graph looks great. Notch out that nasty bump at 70 Hz and you're in business. Of course, you'll also want to plot both subs running together. And don't forget to use a target curve when applying brucek's house curve filter. :T

Regards,
Wayne

 

[thebuffman]

Have no idea what "ME" or "MO" mode is, but the graph looks great. Notch out that nasty bump at 70 Hz and you're in business. Of course, you'll also want to plot both subs running together. And don't forget to use a target curve when applying brucek's house curve filter. :T

Regards,
Wayne

sorry man. the graphs are both subs running together. me + mo = one sub in max output and the other in max extension. should i post a graph of the subs individually?

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?

 

[Wayne A. Pflughaupt]

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

 

[thebuffman]

So each trace is both subs running together, not each sub separately? :scratch:

precisely. each trace is both subs running together. i didn't see a benefit in posting graphs of my subs individually.

 

[thebuffman]

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?

 

[thebuffman]

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

 

[Wayne A. Pflughaupt]

Hmmm... What happened to that severe dip at 90 Hz? :scratch:

Your predicted curve looks good. You might go ahead and dial up a filter at 85 Hz and see what happens. If the peak reappears after the mains are added, then you can take out that filter.

Regards,
Wayne

 

[thebuffman]

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.

 

[thebuffman]

how is this? i also disabled the 1/6 smoothing so you could see some of that 90hz dip you spoke about

 

[Wayne A. Pflughaupt]

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

 

[thebuffman]

Wayne your mentoring paid great dividends! :yay2: Take a look at my finalized dual subwoofer graph with the FBD in-place and fully functional. I removed that bump @ 45hz as well. I ran a test tone against the equalized subs. What do you think?

 

[Wayne A. Pflughaupt]

Nice! :T

Regards,
Wayne

 

[thebuffman]

Nice! :T

Regards,
Wayne

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:

 

[Wayne A. Pflughaupt]

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

Relax – take a deep breath! It’s not nearly as bas as you think! If your subs have a variable phase control, it might clean up things around the crossover frequency. It might be easier to do that with REW’s RTA function, which will let you see the response changes in real time.

Regarding the mains, the away-from-the-wall response (green chart) is much smoother overall (at least between the crossover frequency and 200 Hz!). I‘d go back with that. Beyond that it looks like the sub level could be brought up – I’ll bet the bass sounds a bit weak at the moment. After that you should be in business. :T

Regards,
Wayne

 

[thebuffman]

Relax – take a deep breath! It’s not nearly as bas as you think! If your subs have a variable phase control, it might clean up things around the crossover frequency. It might be easier to do that with REW’s RTA function, which will let you see the response changes in real time.

:whew:thanks for lifting that heavy load:whew:
unfortunately i do not have variable phase control. i can only set it for 180 or 0. i am going to switch to 180 and see what it looks like. i'll post final results.

Regarding the mains, the away-from-the-wall response (green chart) is much smoother overall (at least between the crossover frequency and 200 Hz!). I‘d go back with that. Beyond that it looks like the sub level could be brought up – I’ll bet the bass sounds a bit weak at the moment. After that you should be in business. :T

okay, thanks for the insight. i'll stick with pulling the mains away from the wall, and bring up the sub level one notch on both subs. how did you notice that i had dropped the subs' level down? and what is an appropriate level to set them at? i know the general answer is "whatever sounds good to me" but is there a general rule of thought?

here comes my final posting....i would love to get your advice. also if you would delve a little deeper in explaining to me the philosophy behind the subsonic 'hard knee curve' and its integration with the main speakers, i would be most grateful. from my viewpoint, the hard knee curve is designed to give the sound a more dynamic effect but after adding the mains doesn't one lose the dynamic effect one worked so hard to attain? or is the effect still present even though the graphing of the effect changes?

 

[thebuffman]

here are the graphs. the first graph is with the fbd in bypass mode so that you can see the non-equalized room. the second graph is with the fbd in full affect applying all filters.

Raw state (non-equalized) without smoothing

Equalized without smoothing

This is the Full Spectrum 0-1khz smoothed at 1/3 octave