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post #1951 of 9491
Quote:
Originally Posted by ggsantafe View Post

Quote:
Originally Posted by kbarnes701 View Post

..... But we will see. I shall be aiming to keep the number of filters I use to the minimum and have read a lot of useful stuff on this over at HTS.

Keith - can you post any links to the info you have gathered over at HTS? I'd like to get some background on this topic.

 

I have created PDFs of the ones I found most useful - they are below. The documents have links to other links...

 

Behringer Guide

 

More on Behringer

 

House Curve 1

 

House Curve 2

 

House Curve 3

 

The above are in my DropBox public folder. These were enough to give me the basic understanding of what to do and how to use REW to do it. Also see REW Help.

Gear mentioned in this thread:

post #1952 of 9491
Quote:
Originally Posted by kbarnes701 View Post

One thing I am undecided on at this stage is whether to run Audyssey first and then use the PEQ as 'icing on the cake' to make final tweaks to the FR OR to run the PEQ first to get the response where I want it and then run Audyssey. 

Since you can't make any adjustments to Audyssey, my suggestion is to run Audyssey first and then use the DSP to fine-tune the results.

Michael

post #1953 of 9491

How do I know anyone can do it? Because this is what I am able to get with a new Klipsch RW12d and an old HKTS14 in an acoustically disastrous room:

 

 

 

Please don't ask how it got to 115dB, it didn't! (which, of course, makes me somewhat suspicious of posts that do claim 115dB, but that's my problem, not anyone else's).

The Klipsch is rated to 23Hz. I gave it a 4dB bump at 20Hz.

The Klipsch is set for <40Hz, the HK handles 40Hz to 80Hz. 

I expect to play more with waterfalls and such once everyone else gets up and running. I just got an EMM-6 to use with the legacy setup that I have.

So get cracking, folks!

Michael

post #1954 of 9491
Quote:
Originally Posted by LastButNotLeast View Post

Quote:
Originally Posted by kbarnes701 View Post

One thing I am undecided on at this stage is whether to run Audyssey first and then use the PEQ as 'icing on the cake' to make final tweaks to the FR OR to run the PEQ first to get the response where I want it and then run Audyssey. 

Since you can't make any adjustments to Audyssey, my suggestion is to run Audyssey first and then use the DSP to fine-tune the results.

Michael

Thanks. I think this is the way I will go. Craig John gave me the following answer in the SubM thread:

 

"I haven't used the Behringer device, but I have used the Velodyne SMS-1, (which is also an external PEQ), in conjunction with Audyssey. My experience in my own system was that running the PEQ post-Audyssey yielded the best results. (In fact, you have referenced that result in your FAQ.) That result was based on pretty decent pre-Audyssey FR, with no huge peaks or dips that Audyssey had to deal with. The SMS-1 was only used to tweak the final FR a few dB after running Audyssey. For that purpose, it worked extremely well.

 

"However, in another system, I found that using the SMS-1 pre-Audyssey to reduce a huge 25+ dB peak was a significant benefit to the final Audyssey result, Without the huge cut implemented by the SMS-1, Audyssey was expending all it's resources to remove that peak and was therefore less effective at other frequencies. Audyssey has, (IIRC), about 9 dB of cut capability at any one frequency. If that is not close to enough cut for a huge 25+ peak, an external PEQ can be used effectively before running Audyssey to improve the response Audyssey "sees" prior to it's filters. The better the FR Audyssey is given, the better the final result.

 

"In addition, and more importantly, the "Volume Normalization" process was negatively affected by this huge peak and lead to the well-documented ULF boosting. Reducing the peak with an external PEQ reduced the need for Audyssey to increase the overall level, which reduced the ULF boosting seen with the Volume Normalization process.

 

"Bottom line, I think the best answer depends on the pre-Audyssey FR. If your system is pretty good to start with, Audyssey by itself can be highly effective, and the external PEQ can be used post-Audyssey to "tweak" the final result to good effect. However, if your pre-Audyssey FR has a single huge peak that dominates the response, the external PEQ can be used pre-Audyssey to great advantage to reduce that peak."

 

As I fall into Category 1 above, I will follow your, and Craig's, advice initially and see how I get on. Thanks.

post #1955 of 9491
Quote:
Originally Posted by LastButNotLeast View Post

How do I know anyone can do it? Because this is what I am able to get with a new Klipsch RW12d and an old HKTS14 in an acoustically disastrous room:

 

 

 

Please don't ask how it got to 115dB, it didn't! (which, of course, makes me somewhat suspicious of posts that do claim 115dB, but that's my problem, not anyone else's).

The Klipsch is rated to 23Hz. I gave it a 4dB bump at 20Hz.

The Klipsch is set for <40Hz, the HK handles 40Hz to 80Hz. 

I expect to play more with waterfalls and such once everyone else gets up and running. I just got an EMM-6 to use with the legacy setup that I have.

So get cracking, folks!

Michael

 

Is that after EQ-ing?  Can you post your 'before' graphs so I can see where you started from. Impressive result. 

post #1956 of 9491
Quote:
Originally Posted by kbarnes701 View Post

 

Is that after EQ-ing?  Can you post your 'before' graphs so I can see where you started from. Impressive result. 

I will be re-running everything with the new mic as soon as the opportunity presents itself (which, I thought, was going to be this weekend, but, alas, will not). 

Of course that's after, no smoothing. MCACC doesn't do bass, so that's all with the 1124P, 4 filters on one channel, 3 on the other, no fancy MIDI interface wink.gif.

The chances of you not being happy with yours are non-existent.

So let's see YOUR before and afters!

Michael

post #1957 of 9491
Quote:
Originally Posted by LastButNotLeast View Post

Quote:
Originally Posted by kbarnes701 View Post

 

Is that after EQ-ing?  Can you post your 'before' graphs so I can see where you started from. Impressive result. 

I will be re-running everything with the new mic as soon as the opportunity presents itself (which, I thought, was going to be this weekend, but, alas, will not). 

Of course that's after, no smoothing. MCACC doesn't do bass, so that's all with the 1124P, 4 filters on one channel, 3 on the other, no fancy MIDI interface wink.gif.

The chances of you not being happy with yours are non-existent.

So let's see YOUR before and afters!

Michael

 

Thanks. I will post my graphs once I get my hands on the 1124P and have figured out how to use it. How did you achieve that result in the REW EQ section is what I was wondering?  Could you post the 'before' and give me a clue as to how you set about it - what parameters did you set in the right hand panes etc?  I am at the 'fiddling about' stage still but I'd like to apply a little more 'learning' to it.

 

Do you use a house curve BTW?

 

Thanks.

post #1958 of 9491
Quote:
Originally Posted by kbarnes701 View Post

 

Thanks. I will post my graphs once I get my hands on the 1124P and have figured out how to use it. How did you achieve that result in the REW EQ section is what I was wondering?  Could you post the 'before' and give me a clue as to how you set about it - what parameters did you set in the right hand panes etc?  I am at the 'fiddling about' stage still but I'd like to apply a little more 'learning' to it.

 

Do you use a house curve BTW?

 

Thanks.

[Persistent little bugger, ain't he? smile.gif]

I found what is probably a "before:"

 

 

I don't use a house curve. My test is classical music (http://www.amazon.com/Johann-Sebastian-Bach-Brandenburg-Concertos/dp/B001F1YBP8/ref=sr_1_1?s=music&ie=UTF8&qid=1363027403&sr=1-1&keywords=brandenburg+concertos+blu-ray) where I need to hear the cellos over the bass (my original setting, as with most people, was too bass-heavy), rock (http://www.amazon.com/Best-Sound-Stage-Blu-ray-Disc/dp/B001P6DPDW) where I can hear the bass notes clearly throughout the range, and movies (http://www.avsforum.com/t/1412846/the-ultimate-bass-demo-disc) where, of course, I want my brain to rattle.

Considering the system I have, I'm extremely pleased.

Help files for REW are, as you've mentioned, pretty good. The step I kept missing was, under "Target Settings," clicking on "Set Target Level." Then, similarly, under "Filter Tasks," click on "Match Response to Target." Then click on "EQ Filters" above the graph and there they are, the four numbers you need to enter for each filter in the DSP. Easy enough to enter manually, though it does remind me of Reverse Polish Notation (if you're not old enough, that's neither a joke nor a put-down, so just let it be).

 

So does that make the folks who thought we were getting a little off track happier?

Michael

post #1959 of 9491

Okay, before you ask (hopefully), here they are overlapped:

 

 

post #1960 of 9491
Quote:
Originally Posted by kbarnes701 View Post

Thanks. I will post my graphs once I get my hands on the 1124P and have figured out how to use it. How did you achieve that result in the REW EQ section is what I was wondering?  Could you post the 'before' and give me a clue as to how you set about it - what parameters did you set in the right hand panes etc?  I am at the 'fiddling about' stage still but I'd like to apply a little more 'learning' to it.

Do you use a house curve BTW?

Thanks.

Keith, if you get this to work as a post-calibration improvement to what Audyssey delivers, we may want to add this to the REW guide (or to be less distracting, have a separate Behringer guide). All part of that audio nivrvana/graphitis.....
post #1961 of 9491
Quote:
Originally Posted by LastButNotLeast View Post

Okay, before you ask (hopefully), here they are overlapped:



Dang, that's impressive!
post #1962 of 9491
Quote:
Originally Posted by LastButNotLeast View Post

Quote:
Originally Posted by kbarnes701 View Post

 

Thanks. I will post my graphs once I get my hands on the 1124P and have figured out how to use it. How did you achieve that result in the REW EQ section is what I was wondering?  Could you post the 'before' and give me a clue as to how you set about it - what parameters did you set in the right hand panes etc?  I am at the 'fiddling about' stage still but I'd like to apply a little more 'learning' to it.

 

Do you use a house curve BTW?

 

Thanks.

[Persistent little bugger, ain't he? smile.gif]

I found what is probably a "before:"

 

 

I don't use a house curve. My test is classical music (http://www.amazon.com/Johann-Sebastian-Bach-Brandenburg-Concertos/dp/B001F1YBP8/ref=sr_1_1?s=music&ie=UTF8&qid=1363027403&sr=1-1&keywords=brandenburg+concertos+blu-ray) where I need to hear the cellos over the bass (my original setting, as with most people, was too bass-heavy), rock (http://www.amazon.com/Best-Sound-Stage-Blu-ray-Disc/dp/B001P6DPDW) where I can hear the bass notes clearly throughout the range, and movies (http://www.avsforum.com/t/1412846/the-ultimate-bass-demo-disc) where, of course, I want my brain to rattle.

Considering the system I have, I'm extremely pleased.

Help files for REW are, as you've mentioned, pretty good. The step I kept missing was, under "Target Settings," clicking on "Set Target Level." Then, similarly, under "Filter Tasks," click on "Match Response to Target." Then click on "EQ Filters" above the graph and there they are, the four numbers you need to enter for each filter in the DSP. Easy enough to enter manually, though it does remind me of Reverse Polish Notation (if you're not old enough, that's neither a joke nor a put-down, so just let it be).

 

So does that make the folks who thought we were getting a little off track happier?

Michael

 

Terrific - thanks so much for that. Your 'before' is substantially worse than your 'after' which is what I was hoping to see.  What was your maximum dB boost to achieve that nice curve?

post #1963 of 9491
Quote:
Originally Posted by sdrucker View Post

Quote:
Originally Posted by kbarnes701 View Post

Thanks. I will post my graphs once I get my hands on the 1124P and have figured out how to use it. How did you achieve that result in the REW EQ section is what I was wondering?  Could you post the 'before' and give me a clue as to how you set about it - what parameters did you set in the right hand panes etc?  I am at the 'fiddling about' stage still but I'd like to apply a little more 'learning' to it.

Do you use a house curve BTW?

Thanks.

Keith, if you get this to work as a post-calibration improvement to what Audyssey delivers, we may want to add this to the REW guide (or to be less distracting, have a separate Behringer guide). All part of that audio nivrvana/graphitis.....

 

The big word there is IF... ;)  But I am hopeful. If I can get close to what Michael has achieved it will be an improvement on what Audyssey has, so far, managed. But there may be 'unfixable' issues here - I have zero scope for speaker/sub placement adjustments which is what I would be doing first if I was able to. I will of course keep all you dudes informed of my progress, or lack of it.

post #1964 of 9491
Quote:
Originally Posted by angryht View Post

Quote:
Originally Posted by LastButNotLeast View Post

Okay, before you ask (hopefully), here they are overlapped:


Dang, that's impressive!

Isn't it?  And all from a PEQ unit that costs less than 100 dollars. 

post #1965 of 9491
Quote:
Originally Posted by sdrucker View Post


Keith, if you get this to work as a post-calibration improvement to what Audyssey delivers, we may want to add this to the REW guide (or to be less distracting, have a separate Behringer guide). All part of that audio nivrvana/graphitis.....

Already done:

http://www.hometheatershack.com/forums/bfdguide/

post #1966 of 9491
Quote:
Originally Posted by kbarnes701 View Post

Terrific - thanks so much for that. Your 'before' is substantially worse than your 'after' which is what I was hoping to see.  What was your maximum dB boost to achieve that nice curve?

I was about to give you a hard time for making more work for me, but then I realized that I should probably have those numbers in a safe place, anyway. So thanks, sort of, and here they are:

 

left  freq  fine  bw    gain

1     40    -3     9      -9

2     63    +5    8      -7

3     50    +6    6     +6

4     80    -3     9     +3

 

rht   freq  fine  bw    gain

 

1     40    -3     9      -9

2     63    +5    8      -7

3     20     0     6      +4

 

post #1967 of 9491
Quote:
Originally Posted by LastButNotLeast View Post

Quote:
Originally Posted by kbarnes701 View Post

Terrific - thanks so much for that. Your 'before' is substantially worse than your 'after' which is what I was hoping to see.  What was your maximum dB boost to achieve that nice curve?

I was about to give you a hard time for making more work for me, but then I realized that I should probably have those numbers in a safe place, anyway. So thanks, sort of, and here they are:

 

left  freq  fine  bw    gain

1     40    -3     9      -9

2     63    +5    8      -7

3     50    +6    6     +6

4     80    -3     9     +3

 

rht   freq  fine  bw    gain

 

1     40    -3     9      -9

2     63    +5    8      -7

3     20     0     6      +4

 

 

Nice - great what you have achieved with a small number of well-chosen filters.  Next question (oh you thought I was done huh? smile.gif ) - how did you arrive at those numbers?  looking at your graphs it seems fairly obvious that the numbers you picked would work - is it really that easy?  Did you experiment a lot with REW's EQ section?

 

And how did you know how the two subs would interact once the individual filters had been made? This is something I am struggling with - if I want to EQ both subs differently, how will I know how they will play together when being used in the real world?  Is it just trial and error?

post #1968 of 9491
Quote:
Originally Posted by Pres2play View Post

Beyond 70 Hz, the curves are going in different direction. Is this a phase problem?
Could be, since low frequency drivers on opposite sides can be out of phase with each other, which is what allows a pair of subs on opposite walls to cancel each other's peaks & dips. Or it might just be the result of two separate locations influencing the same speaker differently (though I'll admit the criss-cross pattern looks suspiciously like one is out of phase with the other).
post #1969 of 9491
Quote:
Originally Posted by kbarnes701 View Post

Nice - great what you have achieved with a small number of well-chosen filters.  Next question (oh you thought I was done huh? smile.gif ) - how did you arrive at those numbers?  looking at your graphs it seems fairly obvious that the numbers you picked would work - is it really that easy?  Did you experiment a lot with REW's EQ section?

 

And how did you know how the two subs would interact once the individual filters had been made? This is something I am struggling with - if I want to EQ both subs differently, how will I know how they will play together when being used in the real world?  Is it just trial and error?

Yes, it is that easy. Really. REW is amazing. Complicated, sometimes obtuse, but amazing.

I'm afraid I don't remember my exact process. I know I have the high pass filter on the Klipsch at 50Hz. I probably just ran them both together and plugged the numbers into both channels. Then I goosed up the Klipsch at 20Hz.

Stop worrying. Just play around with it a little.

Fun, remember? Fun!

post #1970 of 9491

In the meantime, we haven't heard from the OP in months.

Probably scared him away.

jevansoh?

post #1971 of 9491
Quote:
Originally Posted by angryht View Post

Wow, Sanjay, adding the second sub really smoothed things out overall and even extended the low end a bit. The graph below is the best I could do with 2 subs and adjusting the phases and the volumes.
Looking good. Where are the two subs placed?
Quote:
Originally Posted by angryht View Post

Towards the end of my measuring session I checked the center speaker with the 2 subs and got a dip at about 76 Hz. I am guessing that dip is a result of the interaction of the center speaker with the subs and the set to a crossover at 80 Hz . Any thoughts on how to minimize that? I adjusted the phase on the sub to get the best frequency response for that alone. Do I need to continue adjusting the phase of the sub(s) with the center and subs combined? Or should I start adjusting the distance settings for the center and sub? Or both?
Use the phase and gain knobs to improve interaction between the two subs (after having done that with placement alone). Once you've gotten as far as you can go with the subs, leave those knobs alone. To adjust interaction between your subs and centre speaker, use the subwoofer delay in your receiver.

BTW, if you don't want to use the level knob on the subs to improve response, because you prefer to have the subs gain matched, then that's fine. There are different approaches to addressing low frequencies and some (Geddes, Harman) adjust gain as part of their process while others don't.
post #1972 of 9491
Quote:
Originally Posted by sdurani View Post

Looking good. Where are the two subs placed?
Use the phase and gain knobs to improve interaction between the two subs (after having done that with placement alone). Once you've gotten as far as you can go with the subs, leave those knobs alone. To adjust interaction between your subs and centre speaker, use the subwoofer delay in your receiver.

BTW, if you don't want to use the level knob on the subs to improve response, because you prefer to have the subs gain matched, then that's fine. There are different approaches to addressing low frequencies and some (Geddes, Harman) adjust gain as part of their process while others don't.

The subs are in the center of the back wall and just off the center of the front wall. My approach was to get the single sub in the best place and then get the second one in the opposite side of the room to try and balance things out. When I tried them on opposite sides of the width, there wasn't much change.

I think I've gotten as far as I can with the phase adjustments, so I guess I'll move forward to the delay/distance adjustments. I did not do a lot of adjustments with the gains of the individual subs. I just matched them and then I turned down the larger one to get the frequency response as close to flat at the low end. I thought maybe the phase adjustment on the sub might help smoothing out the interaction with the center. I'll leave it alone and do the distance adjustments. Should I keep the distance on the speakers (LR&C) or should those be set to zero? Again, thanks for your help!



I also wonder if I should measure the subs and then the center separately to see how they are by themselves.
post #1973 of 9491
Quote:
Originally Posted by angryht View Post

The subs are in the center of the back wall and just off the center of the front wall. My approach was to get the single sub in the best place and then get the second one in the opposite side of the room to try and balance things out. When I tried them on opposite sides of the width, there wasn't much change.
IF you're in the mood to experiment before you lock in your layout, you might want to try both subs behind your couch, each ¼ of the way in from the side walls.
Quote:
Originally Posted by angryht View Post

Should I keep the distance on the speakers (LR&C) or should those be set to zero?
Your L/C/R speakers should be time aligned as normal (distance from main listening position). Try varying the delay on the subwoofer output to see whether that reduces the dip around the crossover point.
post #1974 of 9491

For anyone from the US thinking about picking up a Behringer, Guitar Center has a pretty good St Patrick's Day sale going.  $20 off $100 with free shipping brings it down to $89.  Here's a link for reference:

 

http://www.guitarcenter.com/Behringer-Feedback-Destroyer-Pro-DSP-1124P-101586667-i1125205.gc

post #1975 of 9491
^Thank you for that heads up.
post #1976 of 9491
Quote:
Originally Posted by sdurani View Post

IF you're in the mood to experiment before you lock in your layout, you might want to try both subs behind your couch, each ¼ of the way in from the side walls.
Well, I took your advice and kept on experimenting. When I put both subs at the quarter points (from the side walls) against the back wall, the result was a little worse than the previous tests (subs at the center of the front and center of the rear wall). However, then I put one at each opposite corner, one about 1/4 from the right wall against the front wall and the other about 1/4 from the left wall against the back wall and the response got better, at least I think so. There is a new hump near 115 Hz, so we'll see how that integrates with the other speakers. Actually, my receiver has EQ setting for the sub at 100 Hz so maybe. . . . .I'll hold off on EQ'ing for now.

Purple=center of front and back walls
Black=left rear and right front corners


Thanks for suggesting I keep checking locations, Sanjay!

. . . and to review, here is a comparison of the best I could do with one sub and where I am with 2 subs.

Green=1 sub, center of back wall
Blue=2 subs in the corners


Seems I've come a long way.smile.gif
Quote:
Originally Posted by sdurani View Post

Your L/C/R speakers should be time aligned as normal (distance from main listening position). Try varying the delay on the subwoofer output to see whether that reduces the dip around the crossover point.

That's next on the list. Thanks again.
post #1977 of 9491

Quote:
Originally Posted by angryht View Post
Seems I've come a long way.smile.gif

That looks great.

Now take your DSP and:

40   -2   4   -2

to get the hump at 40 even, then:

40   -8   10   -4

to bring that whole section down to the rest of the graph. Then, just for fun:

25   0   6   +6

to boost up 25Hz.

 

Just sayin'.

wink.gif

Michael

post #1978 of 9491
Quote:
Originally Posted by LastButNotLeast View Post

That looks great.
Now take your DSP and:
40   -2   4   -2
to get the hump at 40 even, then:
40   -8   10   -4
to bring that whole section down to the rest of the graph. Then, just for fun:
25   0   6   +6
to boost up 25Hz.

Just sayin'.
wink.gif
Michael

Thanks, Michael, a couple of questions. I'm not very familiar with EQ terminology, so forgive me if these have obvious answers. I need to do more reading on that.

  1. Are the 4 numbers that you list:
    • Frequency
    • Fine (? not sure what that is?)
    • bw (band width?)
    • Gain (in dB)

    Is that right? My DSP only has gain from -6 to +6 for 25 Hz, 40 Hz, 63 Hz, 100 Hz and 160 Hz. It does not have bw or fine settings.

  2. Should I start EQ'ing now or wait until I integrate the center and mains with the distance/delay settings? It seems logical to try and get the flattest response for the sub. And since there are separate settings for the sub and the mains and center, if I got the sub as smooth as possible to start with, that would make sense. But I can understand waiting to see.
post #1979 of 9491
Quote:
Originally Posted by angryht View Post

However, then I put one at each opposite corner, one about 1/4 from the right wall against the front wall and the other about 1/4 from the left wall against the back wall and the response got better, at least I think so.
I think that's a stunning improvement from what you originally had. The bass is getting smoother and flatter, and the difference ain't subtle.
Quote:
Originally Posted by angryht View Post

There is a new hump near 115 Hz, so we'll see how that integrates with the other speakers.
Might not be an audible problem, depending on where you set your crossover.
post #1980 of 9491
Quote:
Originally Posted by jkasanic View Post

For anyone from the US thinking about picking up a Behringer, Guitar Center has a pretty good St Patrick's Day sale going.  $20 off $100 with free shipping brings it down to $89.  Here's a link for reference:

http://www.guitarcenter.com/Behringer-Feedback-Destroyer-Pro-DSP-1124P-101586667-i1125205.gc

Is there a promo code to get the $20 off? I've got it in my cart but it's showing at full price.
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