which frequencies?

**dimmie** · **09-12-06, 06:00 PM**

Ok, I detected the peaks and applied two auto filters and one manual, because of a small peak that remained. But after this I guess it's time to start adressing the dips....

What should the next step be?.

**brucek** · **09-12-06, 06:21 PM**

Quote:

What should the next step be?.

Well, that's up for debate.

I see you've used a target of 150Hz. Why did you choose that and not 100Hz?

Either way, You've done a good job, although I might add a filter to reduce the peak at ~80Hz somewhat.

As far as the dips are concerned, I'm not a big fan of using gain when using a parametric amplifier, since it reduces headroom in the unit itself. A small amount can be tested on dips to see if it's effective. Don't ever go over +5dB....

brucek

**dimmie** · **09-12-06, 06:34 PM**

Headroom won't be a problem(for the sub), is there nothing I can do to get my response better than it is now?, I figured this was just the starting point....

Are all the remaining low points in my graph basicly non-treatable?

I'll trie 100 hz. if you thinkÏ'll get better results that way, or even 80. My goal was to treat the subs response as far as I could. All the way up to 150 hz.

**brucek** · **09-12-06, 06:43 PM**

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Headroom won't be a problem

Really, how have you determined that?

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My goal was to treat the subs response as far as I could. All the way up to 150 hz

That's not the way it's really done. You choose a crossover first, taking into consideration the low end response of your mains. If they're capable you choose 80Hz. If they're not, you can go as high as 100Hz. After that the sub is far to localizable.

Set your crossover and create the filters to get the best response for that target. Add the mains and tweak anything around the crossover - that's it.

If you have a bunch of dips, them's the breaks - not much you can do except add a little gain - and I mean a little. Every dB of gain comes off your headroom or reduces dynamic range....

brucek

**dimmie** · **09-12-06, 07:06 PM**

I was under the impression that headroom referred to the sub....I was pretty confident that I had enough on the sub to play with. But you're referring to the bfd?, Ok I didn't know.

Have you ever seen a graph as bad as mine?, weak below 30 hz., weak between 50 and 80 hz. those are important freqencies I believe...

I'll trie to go for 100 hz. x-over..see what happens.

**dimmie** · **09-14-06, 03:56 PM**

I'll trie it at 100 hz. x-over. see if I can get better results that way.

I put the mic. in the middle of the room, and came up with this. probably a better location to sit, right?.

Maybe I should measure the keffs first, to see how low they'll realy go. and then choose my crossover

**brucek** · **09-14-06, 05:51 PM**

Quote:

I put the mic. in the middle of the room, and came up with this. probably a better location to sit, right?.

Well, it's usually the worst you can choose.....

100Hz cross looks like it's good - I would leave it there.

Do you have problems with the way your systems sounds now after applying the filtering?

brucek

**dimmie** · **09-14-06, 05:57 PM**

Just another thought.....

I started to raise to gain on the sub, and further decrease the gain on my three filters(for the peaks). I fgured that the more I reduced the gain on my peaks, the closer they would get to where my dips are. And it seems to work.

Here my latest graph.

Is there any fault to my way of working now?, because the graph looks a h*ll of a lot better now....

I do have one question though: The behringer doesn't seem to apply double filters on the same frequency, because when I upped the sub's gain I developed new "peaks" and by adjusting my excisting filters I put them down to my target level again. bringing them closer to the low points in the graph.

**dimmie** · **09-14-06, 06:02 PM**

Quote:

brucek wrote:

Well, it's usually the worst you can choose.....

100Hz cross looks like it's good - I would leave it there.

Do you have problems with the way your systems sounds now after applying the filtering?

brucek

I feel that the bass is not what it should be, I feel I'm realy missing some stuff in the bass department. The boom has reduced!, that's a fact, and I can turn my system all the way up now with proper bass at high volumes, which has been a problem lately(because of the amp's bass management). which I turned off now. So I feel I've gained quite a lot already, and if you look at the above, maybe even more!......

Thanks brucek,

dimitri

**brucek** · **09-14-06, 06:49 PM**

Quote:

Is there any fault to my way of working now?, because the graph looks a h*ll of a lot better now....

It's fine as long as you don't go too far with it.

You're simply changing the level in relation to the target. Think of it this way. If you did a measurement and all the signal was below the REW target, then no filters would be suggested. If you increased the gain of the subwoofer amp and the signal was somewhat above the target, then REW would suggest filters for all the peaks. While these filters would solve the peak problem, you've lost headroom in your subwoofer amplifier by turning it up. If the amp has lots of headroom your fine.

Maybe work on that peak at 80Hz a bit...... and perhaps the one at 38Hz.....

brucek

**dimmie** · **09-14-06, 07:12 PM**

Quote:

brucek wrote:

It's fine as long as you don't go too far with it.

You're simply changing the level in relation to the target. Think of it this way. If you did a measurement and all the signal was below the REW target, then no filters would be suggested. If you increased the gain of the subwoofer amp and the signal was somewhat above the target, then REW would suggest filters for all the peaks. While these filters would solve the peak problem, you've lost headroom in your subwoofer amplifier by turning it up. If the amp has lots of headroom your fine.

Maybe work on that peak at 80Hz a bit...... and perhaps the one at 38Hz.....

brucek

That was the next thing I wanted to ask you.....I already tried to fix the peak at 80 hz. but no amount of cut will decrease it....

Can peaks be as stubborn as dips?,

I've got loads of headroom on the sub, it's pretty powerfull. I believe I'm not even using 25% on it right now, with the lfe channel on the amp set to -5. I believe I've increased the cut on my excisting filters about - 7 db.

I've been testing with "the incredibles" and the bass seems a lot more tight and in place. Whenever I take a reading on the spl meter, it's a lot more stabile, in the unequalized situation it's all over the place when I take a reading.

Any tips on the 80 and 38 hz. ?

Dimitri

**brucek** · **09-14-06, 07:48 PM**

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Can peaks be as stubborn as dips?,

Nope. You must not have had 80Hz selected or the filter was not in PA mode. Be sure you had 80 and not .80 selected.

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I've got loads of headroom on the sub,

Yep.

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Any tips on the 80 and 38 hz

hehe, enter filters at those frequencies and cut......remeasure and see how you did....that's it.

brucek

**dimmie** · **09-14-06, 08:09 PM**

Will do.....

**JohnM** · **09-15-06, 03:56 AM**

Quote:

dimmie wrote:

I already tried to fix the peak at 80 hz. but no amount of cut will decrease it....

That resonance is probably being driven by your main speakers so filtering the sub won't help, could confirm that by turning off the sub and re-measuring. Try inverting the sub phase to see if that makes the overall response better or worse.

**dimmie** · **09-15-06, 04:09 AM**

Thank you for that one john, I'll give it a go tonight.

Dimitri

**dimmie** · **09-15-06, 05:00 PM**

Here's the latest one....

I'm now using 8 filters, the bass is pretty ok now, but I feel that the integration with the satelites isn't what it should be. What's the best way to get fix this problem?.

thanks again

dimitri

p.s. I'm also just randomly inputting filters, should the lowest one be the first?.

**brucek** · **09-15-06, 06:09 PM**

Quote:

I'm also just randomly inputting filters, should the lowest one be the first?.

Doesn't matter.

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What's the best way to get fix this problem?.

What problem? Looks like you've equalized the subwoofer - job done.

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I already tried to fix the peak at 80 hz. but no amount of cut will decrease it?

You didn't say how you eliminated your pesky 80Hz problem that you said wouldn't respond to a filter..

brucek

**dimmie** · **09-16-06, 01:46 PM**

Quote:

You didn't say how you eliminated your pesky 80Hz problem that you said wouldn't respond to a filter..

Well...just like you said, I had the .80 selected, and not 80.

But after having tested with different material, I've concluded that I don't really like my bass response now with the 8 filters. It looks good on paper but a house curve doesn't have to be a flat line right?...

It sounds really "engineered" now. and not dynamic at all.

I guess I'll test some more and see what happens. Any tips would be appreciated.

Dimitri

p.s. I've got 2 filters on now, with better "perceived" results.

**09-17-06, 06:19 AM**

What you'll find is the response will vary depending where you sit the room. You've only eq'ed for one position so anywhere out of this zone will be all over the place. In some cases it can actually be worse than before in other seats. This is where having room treatments helps smooth things out so it's not as different in all the seats.

**brucek** · **09-17-06, 01:42 PM**

Quote:

Well...just like you said, I had the .80 selected, and not 80.

Yeah, it's a really common mistake. I blame the BFD for its poor indicators. Since your crossover was 100Hz, it wasn't likely your mains causing the problem because they have much less effect at 80 Hz than the sub itself... Glad you found it.

Quote:

a house curve doesn't have to be a flat line right?...

A house curve isn't a flat line at all. It's a curve. In fact, I would suggest that your dislike of the sound has to do with the fact that your sub is at exactly the same level as your mains. Turn it up a few dB and see if it sounds better..

brucek

**dimmie** · **09-17-06, 02:35 PM**

Does the amount of filters used have a possible negative effect on your sound?, which would you say is better: using a lot of filters and getting a smoother curve or less filters and getting an almost as smooth curve?. I just felt that, to achieve a 2-3 db. cut, with an extra filter, will cost you more than you will gain....

I've tried the two testtones: 32 and 100 hz. to see if the perceived volume comes close, but no, not even with the wide cut at 366hz. as described in the house curve thread.done just for the of it.

I came up with this one last night.

p.s. from a h 100 hz. up it looks pretty bad also, can I do anything about that?.

**brucek** · **09-17-06, 03:06 PM**

Quote:

which would you say is better: using a lot of filters and getting a smoother curve or less filters and getting an almost as smooth curve?. I just felt that, to achieve a 2-3 db. cut, with an extra filter, will cost you more than you will gain....

Good question - it depends I guess.

Each filter comes at the expense of a modified phase at its frequency that may cause more problems than the cut or gain solved. It all depends on your system. You be the final judge. I find most people on these forums frigg around too much with a dB here and there and it doesn't matter a because if they move a foot one way or the other it's all different.

The big bonus comes from reducing those large wide peaks caused by resonances. Once that's done the rest is just for fun....

Again I say... looking at your graph (which is really good), I would recommend turning up your subwoofer amp a few dB and see if it sounds better. Then you're done. Live with it for a while.

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p.s. from a h 100 hz. up it looks pretty bad also, can I do anything about that

Joint the club. Some people find certain room treatments solve specific problems, but I think most people have a graph above 100Hz that looks like yours.... It's the low frequency peaks that cause all the trouble......

brucek

**dimmie** · **09-17-06, 03:28 PM**

I'm gonna screw around a little more, see what happens....

Thanks a million for your help brucek.

They're not paying you enough.........probably nothing

p.s. maybe look at the crossover point dip, see if it's a phase problem.

**dimmie** · **09-17-06, 05:36 PM**

I just played with the sub distances in the amp menu.....

can it be that the measured distance isn't right at all?.....it seems to be.

Taking into consideration the extra ms that the behringer uses I measured 3.9 m. 3.6 for the sub + 0.3 for the behringer.

Here are the graphs.

I'm sorry but I don't know how to make them all visible underneath eachother.

**brucek** · **09-17-06, 11:13 PM**

Quote:

can it be that the measured distance isn't right at all?

The mesaured distance is no doubt correct. Once set, we normally then adjust the subwoofer phase control to correct to the best resulting signal around the crossover region.

If you don't have a phase adjustment, you can substitute a time delay adjustment on the sub which will act as a reasonable approximation for a phase adjust.

You have demonstrated this in your graphs in that as the time changes the crossover region gets better.

brucek

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