# Center and Sub Issues



## Ares (Nov 23, 2009)

Hey Gang it's been awhile since I have posted anything on this side, spent a lot of time on the gaming forum side. I have 2 issues here and need some advice on how to address them. I have tried everything I could think of from crossover setting, placement and so forth but to no avail.

1) The sub has localization issues that I can't seem to get rid of.

2) When I'm watching movies or just TV viewing you can tell that the dialogue is coming from the center instead of giving the illusion that it's coming from the screen which is kind of distracting.

before this question gets asked I have tried to do proper placement of the speakers as the room would allow, the center is slightly below and 6" in front of the TV which is really the only place I could but it at the moment. The Sub is in front left side of the room with 3" clearance from the front wall and 5.5" off the side wall, I have everything set to small, crossover 80Hz for all.

So any help that you guys can provide will be most appreciated Thank You.


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## dyohn (Apr 17, 2008)

In general, localization of the sub is due to crossover frequency too high. How do you have it set? As to your center channel, if it's in the only location you can realistically use then you may just have to live with it. You can also try adjusting the timing (speaker distance) in your preamp settings. Compare the settings for the front mains and the center, and set the center so it is a couple feet "closer" than the mains. This will add a slightly longer time delay to the center and may help make it sound like it is further "back" in relation to the screen.


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## nova (Apr 30, 2006)

You can also try to aim your center up, couple of wedges under it or something. That may help with your dialog issue.

Also, try your crossover at 60Hz for those T45's. I assume you are using the Denon's crossover? If so, make sure your sub's crossover is off or set to bypass.


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## JBL Fan (May 1, 2010)

Localization starts at around 75hz....


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## lsiberian (Mar 24, 2009)

According to Floyd E. Toole 80hz is a low enough crossover for localization to be unnoticed. I suspect that it's your sub/room interaction that are to blame. I know upgrading to my DIY sub eliminated the localization in my setup. 

For the center try phantoming, I've found I prefer it and it's free.


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## Ares (Nov 23, 2009)

Okay I will give some of those things a try and report back, 

Mark if I cross the fronts at 60Hz and left everything else at 80Hz will there be an issue? I have the center angled up 2.5" so that the tweeter is on the level with the T45's tweeters.

David I have everything crossed at 80Hz in regards to distance both the fronts are at 5.9ft and the center is at 5.6ft so if I understand you correctly I should move it anywhere from 5.5ft-3.6ft is this right? 

lsiberian I know 80Hz is what is usually recommended as a starting point but I am still able to pick out the sub even @80Hz is that unusual?


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## nova (Apr 30, 2006)

Tony,
Mains at 60 and rest at 80 should cause no problems at all. My mains are pretty good down to about 27 so I usually have the crossover at 60, sometimes 40.

I gotta admit, I'm a bit curious about your sub settings. It really should be pretty hard to localize if the crossover is at 80. Are you sure the sub is only getting the LFE? By chance do you have your mains set to large? And your sub set to LFE + Mains in the Denon set-up?


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## Ares (Nov 23, 2009)

Hello Mark, I thought at first this was all in my head so I gave my cousin a call and told him to come over I asked him to place the sub in my room without letting me know where he placed it and to re run Audyssey and to set the crossover for everything @ 80Hz and to set all the speakers to small, I left the house so he could do this I came back to the house after he did it, I told him to blindfold me so I could not see the sub even after going through all this I could still pick out the sub. The mains are set to small, the sub is set to LFE in the Denon set-up I don't know if this matters but LPF for LFE is set to 120Hz in the Denon set-up.


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## waldo563 (Apr 26, 2009)

Ares said:


> The mains are set to small, the sub is set to LFE in the Denon set-up I don't know if this matters but LPF for LFE is set to 120Hz in the Denon set-up.


Tony,
I think that may be your problem. With a 120Hz setting for the Low Pass Filter in your Denon setup, that means that the Low Frequency Effects channel is playing all the way up to that frequency and 120 Hz can be localized. I would recommend changing your LPF to 80 Hz and see if that fixes it.


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## dyohn (Apr 17, 2008)

Agreed. 120Hz is a bit too high. Try 80Hz.


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## Ares (Nov 23, 2009)

Okay I will give that a try, you guys are the first to say to set it at 80Hz every bit of info I could find always says to set it at 120Hz. I moved the sub to the rear since I have more room back there to make adjustments if needed. The sub is 18" off the side wall and 2'7¾" off the rear wall, I am rerunning Audyssey at the moment I will let you guys know how it turns out.


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## perritterd (Mar 11, 2010)

dyohn said:


> Agreed. 120Hz is a bit too high. Try 80Hz.


Hi David, would you still do this if you are using Audyssey for your speaker setup? Only asking because I read many threads about not reducing Audyssey's setup numbers...

Thanks, 
Bob.


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## waldo563 (Apr 26, 2009)

perritterd said:


> Hi David, would you still do this if you are using Audyssey for your speaker setup? Only asking because I read many threads about not reducing Audyssey's setup numbers...
> 
> Thanks,
> Bob.


Bob,
I would still recommend 80 Hz at least as a starting point. 80 Hz is pretty much standard as a starting point and aligns with THX recommendations. In any case, 120 Hz is high enough that there is some localization and that frequency range should be easily covered by all but the smallest cube speakers. I'm pretty sure that Audyssey doesn't change your LPF value, just the settings for the other channels.


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## Ares (Nov 23, 2009)

Audyssey is done and here's the settings:

Speaker Config

Fronts: Large- changed to Small
Center: Small
Rears: Small

Distance

Front L: 5.9ft
Front R: 5.8ft
Center: 6.5ft
Sub: 5.8ft
Rear L: 4.9
Rear R: 5.2

Channel Level

Front L: -6.0dB
Center: -5.0dB
Front R: -7.5dB
Rear R: -7.5dB
Rear L: -8.0dB
Sub: +3.0

Crossover

Fronts: -Full Band- changed to 80Hz
Center: 60Hz changed to 80Hz
Rears: 60Hz changed to 80Hz

Now I have noticed that localization is not as pronounced as before, but the center is still an issue. So what do you guys think?

P.S. LPF for LFE setting is now at 80hz


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## perritterd (Mar 11, 2010)

waldo563 said:


> Bob,
> I would still recommend 80 Hz at least as a starting point. 80 Hz is pretty much standard as a starting point and aligns with THX recommendations. In any case, 120 Hz is high enough that there is some localization and that frequency range should be easily covered by all but the smallest cube speakers. I'm pretty sure that Audyssey doesn't change your LPF value, just the settings for the other channels.


Thanks for the reply waldo563...I have THX Select speakers. My sub is a cheapo but does the job. If Audyssey sets the sub up to 120 hz on the LPF, you would still suggest trying 80 hz?

Bob


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## waldo563 (Apr 26, 2009)

Tony,

It's good to hear that changing the LPF setting helped with the sub. However, I'm not sure there is much that can be done to reduce localization from the center since it has to deal with all of the higher frequencies. Perhaps you can try aiming it so that the tweeter is not pointed directly at you but just misses since the higher frequencies contribute more to localization.


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## waldo563 (Apr 26, 2009)

perritterd said:


> Thanks for the reply waldo563...I have THX Select speakers. My sub is a cheapo but does the job. If Audyssey sets the sub up to 120 hz on the LPF, you would still suggest trying 80 hz?
> 
> Bob


Bob,

I would definitely start with 80 Hz. In most cases, that will be where you want to leave it but of course as is the case with most setup decisions, let your ears be the judge. You may want to tweak it from there but I believe that's where the majority of people have it.


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## lsiberian (Mar 24, 2009)

My surrounds don't do 80hz and I don't have issues anymore. I suspect your sub might be the issue. 

Some subs overemphasize the upper frequencies and as a result your filter isn't as effective at making it non locatable. Try the 60hz crossover.


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## Ares (Nov 23, 2009)

lsiberian said:


> My surrounds don't do 80hz and I don't have issues anymore. I suspect your sub might be the issue.
> 
> Some subs overemphasize the upper frequencies and as a result your filter isn't as effective at making it non locatable. Try the 60hz crossover.



I will give it a try and see what happens, thanks lsiberian


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## Ares (Nov 23, 2009)

Hey Gang, This was an ordeal to get everything right, first things first I decided to basically rip the room apart and started from scratch. I bought a larger area rug then I proceeded to move the LP up 1ft after that it was time to focus on the sub, I download some test tones 20Hz-100Hz had to make sure they were Wav files copied them to the PS3 HDD. Now it was time to figure out sub placement from everything I have read they always make it sound easy, but it's not as simple as they make it out to be at least in the guides so I consider them just that guides nothing more. I also downloaded Real Traps ModeCalc to help in the process along with some math, so now placement of the sub is 3'.5¼" off the back wall , 1'.8" off the side wall and 2'.2½" off the floor this was done for a crossover @80Hz. I went ahead and played the Wav files the 80Hz file was off so before I continued I went and ran Audyssey one more time and of course all the settings changed:

Distance:

Fronts 5.0
Center 5.0
Surr L 5.7
Surr R 6.1
Sub 6.7

Channel Level:

Front L -7.0
Center - 6.5
Front R - 6.5
Surr R - 6.5
Surr L - 6.5
Sub + 3.5

Well after all those changes I did I am happy to report I no longer have a localization issue with the sub and the center has disappeared. What I have I learned from all this location, location, location for the sub and experiment with placement of everything that is not nailed down Thanks Guys for all your help an ideals.


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