My sub sounds better after EQ'ing it using the BFD, but... (1 Viewer)

[DanSt]

Ok...after using everyone's adivce I think I have come up with my final curve or close to it. MarkFrab gave me the starting filters (Thanks Mark!!) and Wayne gave me that excellent explanation of BW above which helped me with the other filters (Thanks Wayne). Above is a graph showing the latest results. Sub only is BLUE and sub w/mains is PINK. What does everyone think? Am I finally there Do I need any other changes?
PS-Only 4 filters this time
BTW, I want to send a very big thanks to everyone in this thread who has been helping me. I think the BFD would be on its way back if not for everyone helping me

 

[brucek]

Dan,
Yep, that's more like it - 4 filters would be reasonable, given the unequalized graph you showed us before. Good job.
Wayne did an excellent job detailing bandwidth concerns. His answer is right on the money. The boring mathematical version he mentioned that I did a little while ago is at this URL if you're interested.
Link Removed
My comments on your latest response is that it's excellent. If it sounds good to you, leave it alone. My feeling though is that you need to now increase the wholesale level of your sub with its volume control about 5dB to be equal or slightly greater than your mains. Just try turning it up a bit and see how it sounds. You can use the simple processors speaker setup test tones for this....
Then I think you need a rest from this EQ stuff. Just listen for a while..
brucek

 

[MarkFrab]

Dan,
Please post your final filter settings... inquiring minds want to know!
I agree with Bruce that you'll probably want to notch your sub volume up a bit... I'd do mine about another 6-9dB or so if my curve looked like yours. That should give you a nice rising response from 80-20Hz. That's how I like mine, anyway - YMMV.
Regards.

 

[Wayne A. Pflughaupt]

brucek,

I think the BFD would be on its way back if not for everyone helping me.

The Behringer is almost as aggravating as it is flexible – I’ll take a good analog parametric any day.
brucek and Mark may well be right that you need to turn up the sub now. However, I find the combined curve a puzzle; it looks like the sub and mains are operating with overlapping filters, or that the mains are running full-range. Normally this would be a bad idea for several reasons, but it doesn’t appear the two are interacting in a negative way in your case.
Regards,
Wayne A. Pflughaupt

 

[Mark Seaton]

A few comments and suggestions.
First, while I understand the graph above shows the points you measured nicely, but at this point you should go and change the frequency scale to logrithmic. This will help a LOT with prioritizing problems, and also make a LOT more sense when looking at the filters and bandwidth. On your linear frequency graph, a parameteric filter would look lopsided or asymetrical. On a logrithmic graph it will all make more sense. This will also emphasize that a peak between 20Hz and 30Hz is a LOT larger than a peak between 90Hz and 100Hz. Important differences to understanding how to correct the problems.
As for Wayne's question about the crossover, I forget which mains you have, but if they have much response below the crossover point, this is expected, as the typical crossover is a 4th order L-R low-pass on the subwoofer, and a 2nd order Butterworth high-pass on the mains. This is intended to work with speakers rolling off in this region, and ideally with a sealed speaker with an F3 at the crossover point (THX spec). As such, looking at your graph, if you want to bump up the sub level some (go back and read my comments about sub level and listening level), I would suggest raising the level 2-3dB and then looking at the curve again.
A quick look over your curve, I would look to pull down the peak at 63Hz slightly more, but do NOT create a depression in the combined response. I would also use one of the remaining filters to kill that peak above 100Hz. While it might not appear to be much of a problem, you want to consider any problems that are less than ~20dB down, as especially at these higher frequencies from the sub they can greatly affect the localization of the sub.
Without knowing what is going on with the mains, it's hard to get too picky with the exact curve of the subwoofer. As a general rule, I would look to somewhat reduce the level of the broad peak in the overlap region, but here a general peak is preferred to a depression which would bring you back to the problem you had before.
Again, next time you feel inspired, go ahead and do all THREE graphs that I suggested above up to 150Hz. To review, with the crossover and speakers set to small, first test the subwoofer by only disconnecting your mains, then do the same for your mains by simply unplugging your sub. Finally take the same measurement of the combined system. This is really the proper way to see what is going on.
Regards,

 

[brucek]

Mark,

at this point you should go and change the frequency scale to logrithmic.

The graph is already logarithmic.
A graph of course as you already know can have any scale you like to present data in many different ways. It doesn't change the data, it changes the appearance. You can have linear divisions with non-linear or logarithmic values, or alternately you can have logarithmic values with linear divisions, or linear values with linear division etc, etc.
In this case, the graph is already a logarithmic presentation as you've suggested. It is not linear. Note the equal physical spacing from 20 to 40 to 80. There are twice as many one hertz steps in the later.
When a graph is made of the results of octave-band sound pressure level measurement rather than individual linearly increasing frequencies, the frequency scale is commonly divided into equal intervals. This would be the case of the Excel graph where each successive measurement is a sixth octave higher. This compresses the graph properly as the frequency increases along the lower axis.
This results in a logarithmic presentation of the data. Alternately if you had measured instead at 10, 20, 30, 40, 50, 60, 70, 80,90, 100 etc, then you would have needed to use a logarithmic X scale as you suggested.
brucek

 

[DanSt]

Here is one more latest curve. I did a couple more adjustments. This is sub only. I also raised the volume of the sub if you didn't notice (However, don't go by the numbers on the left as I didn't claibrate using the 1kHz tone this time. I just kind of picked a volume and took measurements.)
Wayne,
I checked my settings again and there are no overlapping filters and I do have everything set for small with an 80Hz xover. I have a Pioneer 49tx and it has MCACC, but I had it set for Front Channel Adj., which doesn't change the sound of the mains, only the Center and Surrounds (which were off for testing). However, just to make sure I turned it off and the results were the same.
Mark Seaton,
My system consists of the following:
Pioneer 49tx
Klipsch RF-7
Klipsch RC-7
Klipsch RS-7
SVS 20-39pc
I will look a little closer at those regions you mentioned. So far I am pleased with the sound. I get a good deal of great sounding bass (Thanks SVS!). I may also do that graph of the "mains only" also, but I think right now I am going to sit back and listen. I haven't watched a whole movie in almost 2 weeks.
MarkFrab,
I had to do a couple more adjustments today, but here are the final filter settings I am using:
32Hz 15BW +4
50Hz 23BW -14
36Hz 10BW +4
Believe it or not I didn't need to use that 366Hz house curve trick. I noticed that once I did my filters the line was already curving down naturally.

 

[Warren_Sc]

So are you getting that whump in our chest?

This thread has been fun.

 

[brucek]

Looks good Dan. As Mark S suggested already, if you want more comments you'll need to supply the three graphs, so we'll have more information to work with.
If you're tired now and want to do it at a later date - we understand........
brucek

 

[DanSt]

Warren,
I get a little bit of chest pounding bass. Mostly from the vibrations through my couch
bruce,
Yea, I would have to say that I am going to take a break now. I still would like to know how my whole system is integrating so I may post those graphs in a few days (or a week ). I went out and bought a few movies last night to test everything out. So far its sounding good. All thanks to everyone here.
The HTF and its members get a big from me. Now its time to sit back with some

and enjoy a movie