# Please: help optimizing my graph



## Ivaols (Dec 29, 2006)

Hi,

I`ve only had the Behringer for a few weeks. At this point i am starting to be satisfied with the sound, but i still want to improve the graph - and the sound. In this regard i would apreciate some expert help.

Xo 80 hz, sub corner placed with two heavy walls, mains set to small. No boosting added, no smoothing to the graph added.

1: 23.23 -2 0.143
2: 27.29 -5 0.143
3: 43.25 -9 0.167
4: 55.72 -4 0.125
5: 79.62 -12 0.067
6: 88.31 -36 0.033

The first graph is the mains alone. Adressing depth, width and accuracy of the soundstage this is the best placement for the speakers. Two different persons, apart from me, have independently come up with this placement. Here is a picture of mains and sub placement:











Here is a graph of the mains alone:











Here is a graph of the sub alone:











Mains + sub not calibrated:











Here is my best calibrating with sub and mains:











Thanks to everyone giving me advice


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## brucek (Apr 11, 2006)

I'm close to simply saying your job is finished, but I have a couple small comments.

1). I guess you have a 2496 rather than a BFD 1124 since you've expressed your bandwidth in Octaves rather than BW/60. Anyway, that .033 octave filter with a -36dB cut is completely unnecessary. In 1124 language, that's a filter BW setting of 1. You cannot hear any difference with a filter of that bandwidth, no matter what your intent was. Cuts that large are not a good idea.

2). I would lower the peak area between 20Hz and 25Hz. It will bring out the low end extension of ~17Hz a bit better.

brucek


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## Ivaols (Dec 29, 2006)

1: Thats correct, i have a 2496. The problem is, as you can see, the peak around 80 hz. I used the extremely small bandwith to only lower 80 hz, and not drag everything else down with it. I will try again with a broader bandwith, and lower cut.

2: Compadro!

Thanks again brucek!


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

What brucek said about the 88 Hz filter. Make sure that the peak there is coming from the sub and not the mains. If it’s the mains, or if it’s at a higher level with the mains than the sub by itself, don’t waste your time with it. 

Regards,
Wayne


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## Ivaols (Dec 29, 2006)

Here is my new filters:

1: 23.23 -5 0.143
2: 27.29 -5 0.143
3: 43.25 -11 0.111
4: 56.37 -7 0.100
5: 78.71 -13 0.100
6: 86.30 -7 0.100

This is the last graph. I did what i`ve been told. Since the speakers have a gain at the 80 hz++ area, i did not try to EQ this. When i removed the speaker wires, and calibrated only the sub, i did this up to the 80 hz area. When connecting the mains i got higher level from 80 hz and up, much higher than the sub alone.

The sub is at the level i prefer when listening to music. 


Sub calibrated up to 80hz











Sub and mains


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## cyberbri (Apr 27, 2006)

Do the mains have a big bass hump, or is the sub just calibrated at a lower level than the speakers (using receiver tones, Avia, etc.)? Looks like you could turn up the sub quite a bit.


And the calibration looks pretty good. It could be flatter, if you are after that. Feel free to post your .mdat (may need to zip it to reduce the size) so I (and others) can play around with it a bit. 

Here's my sub+mains, before (go by blue line, red line is without bass traps):









And after eq'ing:


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## Ivaols (Dec 29, 2006)

If i turn up the sub more the bass get too much. As you can see on the Large graph (mains alone), there is a huge gain from 80 hz. Filling up with bass below 80 hz gives too much bass, i don`t understand that...?

I tried to reduce the size with winzip, but i couldn`t get it down to the required 100 kb. Any sugestion would be appreciated (first time user of winzip).


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## brucek (Apr 11, 2006)

> I tried to reduce the size with winzip, but i couldn`t get it down to the required 100 kb. Any sugestion would be appreciated


You have to fool the system to make it work by adding a .mdat extension to the .zip file, so the forum software thinks it's an mdat file. The maximum allowed for mdat files is 750K. Just make a note in your post for anyone who downloads the file that it is actually a zip file and you need to remove the bogus mdat extension. i.e. call it file.zip.mdat

brucek


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## Ivaols (Dec 29, 2006)

Thanks!

Here is the mdat file. Please remove the mdat extension, and unzip it.

View attachment file.zip.mdat


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## Ivaols (Dec 29, 2006)

Here`s my last EQ. I think its getting nice  And sounds very nice :bigsmile: Have to admit i used 3 db gain on 51 and 64 hz, but with the sub level just bellow nine o`clock i think it will work just fine. Also used 1/6 octave smoothing to show how it sounds in my sweetspot  If this seems ok, i`m ready to shut down REW for a while, relax, and listen to music again :daydream: Thanks again for all the help!


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## cyberbri (Apr 27, 2006)

That looks great. 
If you're like me, you'll probably be fiddling with it again soon. 

What filters did you end up using? I'll play around with it in REW a bit and see what I come up with. 

How does it sound? And when you calibrate the sub and the mains, how do you do it? The bass from the mains still seems up a bit, unless that's just a peak. Maybe you could do some sweeps through 500hz or so.

Also, are you sure you don't have the bass up on the receiver, or any sort of sound processing mode on? Someone on another thread had his receiver set to "Adventure" mode or something, which added bass boost to the mains down in the 30s~40s or so, even though the mains were set to small.


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## cyberbri (Apr 27, 2006)

I couldn't get the zip file to work. Tried to download it 2 times, failed both times. I renamed the file .zip and opened it. There was a file inside, but I couldn't get it out of the .zip file. File size is 523k.


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## Ivaols (Dec 29, 2006)

Hmm, i will look into the zip file after work tonight, and also post my last filters.

The receiver is in normal stereo mode. I do have gained the sub to max in the level settings, where you set level for each speaker. If i dont do that i get a weak signal into the Behringer. Have not touched the speaker eq in the receiver though.

I calibrate the sub + mains with a normal 10 (?) - 200hz sweep. Where do you mean the mains contribute with bass? Above 80 hz for certain, but not under that area...?

What will a sweep up to 500hz show? I`m a newbie you know


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## Hakka (Sep 10, 2006)

Ivaols said:


> What will a sweep up to 500hz show? I`m a newbie you know


I think even when set to 200hz, the sweep actually goes to 400hz.

On the screen that pops up after you press 'new measurement' press the 2 little arrows near the top to pull down the menu and change the end frequency of the sweep to 500hz, then run the sweep. Click on the 'graph limits' button at the top left of REW and change the 'right' setting to 500.

This will show whats happening further up in the bass range, so we can see if you have a hump coming from the mains or if your overall level is even. From the graph you posted it looks as if your sub is a bit low.

I've attached 2 graphs of my system as an example (my current curve is a bit better its an old measurement), in the first graph it looks like my subs might be a bit low in level relative to the mains, you cant tell if there is a hump at 135 or a dip at 200hz. The second graph shows that there is peaks at 115hz and 135hz and the sub level is high relative to the mains.

What type of receiver are you using?

Harry.


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## cyberbri (Apr 27, 2006)

Ivaols said:


> The receiver is in normal stereo mode. I do have gained the sub to max in the level settings, where you set level for each speaker. If i dont do that i get a weak signal into the Behringer.


How did you go about setting the input level?
Personally, I used WotW DTS, Ch5, and set the receiver volume at about -10, since that would be the max I would listen at, and adjusted the sub/lfe level on the receiver so it was near the top but didn't get into the red. To do this, I had to turn up the level of the speakers and calibrate "0" as -5 on my dial rather than "0," since my receiver puts out a really strong sub/lfe signal.





> I calibrate the sub + mains with a normal 10 (?) - 200hz sweep.


I mean, how do you set the level of the sub (on its gain knob) to know that it is "calibrated" as even or "hot" compared to the speakers?

To set the level or gain of the sub, you need to use the SPL meter and play either the receiver's built-in tones or something like Avia. This will play a higher frequency tone, which you set all the speakers to a certain level with, then the same with a low frequency to set the subwoofer level. Most people set the sub even with the speakers, or a few dB hot. If you are using the analog meter, setting the sub "even" with the speakers is already 2~3dB hot because the analog meter is less sensitive down low. 




> What will a sweep up to 500hz show?


As was just posted by Hakka, seeing above 200hz will give you a good idea of how the whole bass region sounds. Under 100Hz is just the mid-/low-bass, and above that is still bass. If you play a track with an acoustic upright bass and turn off the sub, you can still hear most of the sound. So by checking above 200Hz, you can see if 150-200Hz on your graph is a peak, or if the rest of the higher bass region is that high as well. Because it looks like the subwoofer level is lower than the speakers, at least comparing them to the 150-200Hz area in the graph.


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## Ivaols (Dec 29, 2006)

Hakka: i see what you mean, will do a sweep up to 500hz tonight.

cyberbri: I did use SPL meter and the receiver's built-in tones and adjusted it even with the mains and the centers level. Problem is that i think this gives me too much bass when listening to music, hence i lowered it to a suitable level (2 db down). This is 0 for me, and is +10 on the receiver but it never lead to clipping. That said, my neighbours complain when i get loud so i NEVER play loud anymore.

Maybe i should get the 20-30hz region down a bit? 

The subs gain knob is just bellow 9 o`clock AM. 

The graph you post, is this your "music" graph og "movie" graph? Or maybe the same?


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## cyberbri (Apr 27, 2006)

I see.
Yeah, if you could lower the 28~35Hz region a bit, but leave below that, it should help.

My graph is the same for movies and music. For music I calibrate the sub to be about even with the speakers, and for movies I set it 2~3dB above the level of the mains. I use Avia. When I watch movies, it's usually at about -6 to -14, depending on the movie.


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## Ayreonaut (Apr 26, 2006)

You seem to have figured out how to fine tune your response.

For me, the final frontier is EQing for multiple listening positions. I think its the best way to mitigate all of the room resonances. My subjective conclusion is that you'll realize an improvement at the primary position when you've addressed resonances that aren't even apparant from the measurement at that position. You avoid falling into the trap of trying to compensate for dips that only exist at one seat. Simply measure from all of your useful chairs, view them together, and EQ for the average using good judgement. My two cents.


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## cyberbri (Apr 27, 2006)

Good advice. I think in REW there is even an "average" tab where you can select which measurements to include and view an average of the responses. You could take 3 measurements, one in each spot on the couch, and work on that.


I know that in my rectangular room, speakers firing long-ways into it, with the sub in the front left corner, the middle position is average. On the right side, higher sub frequencies are boosted but lower are down, and on the left side of the couch, higher sub frequencies are down a bit and lower frequencies get a boost. So my middle seat is already kind of an average.


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## brucek (Apr 11, 2006)

> Simply measure from all of your useful chairs, view them together, and EQ for the average using good judgement.


Yeah, I have to agree. When I was testing REW V4 I did an EQ to get used to using the new version. I took 8 response around the room in all sitting positions. Even though each one was different, there was still a couple common peaks that they all shared. 

This to me, is where the most important resonances were located. I pressed the Average button and created a single response from the eight.

I let REW find the filters from that average plot and I entered them. Seems pretty good...... Two filters.

It's just another approach that's a bit opposite from the single position, ruler flat scenario that a lot of people use...

brucek


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## Ivaols (Dec 29, 2006)

Thanks to you i`m closing in to something! :T 

I will try your advice Ayreonaut.

Once again, a new improvement of the graph. Have not listened to it yet.

I lowered the 20-30hz region, and raised the sub level. 

Here`s from 15-200 hz:










Here`s from 15-500 hz. Seems like the sub is a little low, but i really cant turn it up more cause of the sound:









Thanks again, you have been realy helpfull!!!


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## cyberbri (Apr 27, 2006)

Ivaols said:


> View attachment 2154


The ~500Hz looks good. Did you apply any smoothing to it? Like 1/6 octave? that would help average out the response in the higher bass freqs. But just drawing an imaginary line through about the "middle" of the higher bass, it looks like it's about on par with the mid-/low-bass from the sub, which is great.


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## Ivaols (Dec 29, 2006)

Its without smoothing. Looks good with smoothing. Think i will settle with this for a while. Try different posistions later. After all, hifi is a bit of a egotrip with the whole sweetspot deal he he.

It helped a lot lowering the 20-30 hz region! If i hadn`t done that there would be no way to raise the sub level without geting to much bass. Took a while to realize that, it feels bad you know to reduce the lower end of the graph


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## brucek (Apr 11, 2006)

> Took a while to realize that, it feels bad you know to reduce the lower end of the graph


If you read what our own Wayne P says about house curves, he implies that the response should go flat at 30Hz down to the low end. No rise below 30Hz. I tend to agree with him.......

brucek

edit: such as this.........


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## cyberbri (Apr 27, 2006)

Yeah, it does. But overall it's better, because that way you get to raise the overall level of the sub, so it's ALL up a few dB rather than just in the high 20s to mid 30s. 

There's some music that extends into the 30s, but by leaving the "house curve" starting in the high 20s, you still get the impact from the LOW stuff without making music (in movies or on CD) too bottom-heavy.  Anyway, that's what I found, and it seems to work. I listen to a lot of music - probably 40% music, 35% TV/movies, 25% video games.


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## Ivaols (Dec 29, 2006)

Brucek: something like this. 6db gain from 80 to 30hz


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## brucek (Apr 11, 2006)

> something like this. 6db gain from 80 to 30hz


Looks pretty good to me..................


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