# first graphs... trying to correct huge dips.



## jayhawk785 (Nov 10, 2009)

http://notbusy.com/c//REW_V5-20110315-204132.jpg









I can't seem to figure out the 60-70hz dip. I'm going to attempt to move subs around a bit--I have two in the front--gear is as follows:

umc-1
velodyne sms-1
xpa-3
upa-2

swan 6.2f fronts
swan 5.2 center
swan bi-polar rear

2 HSU VTF-15h









http://notbusy.com/c/theaterstuff2.jpg

(not letting me post pictures... through UB code... so, have to clicky the linky.

Im calibrating with a rat shack digital meter - macbook pro line-in/out

Let me know if you need anything else, I'd like to think about doing some acoustic paneling in the room where it pitches up, and to the left/right/rear of the fronts.


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## mechman (Feb 8, 2007)

You need 5 posts to post images, links, etc. You can throw a few more posts up here to get to 5.

In the meantime, here is your graph and your room shot. :T


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## jayhawk785 (Nov 10, 2009)

Super duper. here's post five.

Hoping someone can tell me why I'm seeing a huge dip, maybe I should drop the sub from 15hz to 65hz via the sms-1?


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## savior sound (Nov 30, 2008)

Have you run Emo-Q™ on your UMC-1?


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## jayhawk785 (Nov 10, 2009)

I did initially, but tweaked it around a bit. Anything I did in the eq, did not seem to matter... results always seem the same?


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## savior sound (Nov 30, 2008)

What speakers were on when you got those graphs?
I would run each sub alone and then both subs together and then both subs with left front and right front seperately and then finally both subs and both main speakers.
This may give some insight into where this dip might be coming from. A phase or sub distance setting change may help.


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## jayhawk785 (Nov 10, 2009)

I'll try running tonight with >

mains off

sub 1 on only
sub 2 on only
sub 1 and 2 on
sub 1 mains
sub 2 mains
then re-graph sub1/2 + mains

is this granular needed:
sub 1 main left
sub 1 main right
sub 2 main left
sub 2 main right

After that I'm going to try moving the subs into the corners against that wall firing toward each other (parallel to listening position). I have limited ability in where I can put them, due to the size of the screen and the height of the towers.


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## Aujan (Feb 13, 2011)

savior sound said:


> What speakers were on when you got those graphs?
> I would run each sub alone and then both subs together and then both subs with left front and right front seperately and then finally both subs and both main speakers.
> This may give some insight into where this dip might be coming from. A phase or sub distance setting change may help.


+1 on the phase/lobe theory. Test each on it's own and find where the convergence problem is.
Then it's all about position, time alignment and room treatment.

But the fact that you have such a dramatic dip at close to 60hz makes me wonder if you don't have some sort of electrical/ground/wiring interference going on. Don't forget to check your wiring
especially for proper phase.If one of those subs is out of phase it could easily cause that type of dip where the speakers converge.

Best of luck.


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## jayhawk785 (Nov 10, 2009)

Which wiring? Speaker? they are all straight shots from panel to termination point--phase is all correct...

Electrical wiring, I ran a dedicated 20amp circuit.

Amps go to the surge side of a UPS
Monster power cleaner goes to the battery backup side of the UPS 
Everything plugs into the monster power cleaner (other than amps)

I'll checkout the individual speaker measurements see whats going on--maybe take out the sms-1 and measure there too, or just do eq defeat when i measure.


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## Aujan (Feb 13, 2011)

If all of your speaker wiring and input wiring is correct so that there are no phase issues, and evrything
has a good ground with no difference in potential causing ground noise, then take out all eq and anything
else in the chain out and take your individual speaker measurements. The idea is to make it as simple and basic as you can while you troubleshoot. Then you can add things back in along the signal chain as you confirm that the basics are all correct.

BTW, I don't want to get too far ahead of myself, but Is you 20 amp dedicated circuit on opposite phase of your lighting system, especially if you have dimmers? That's a notorious place for audio interference to occur. That's most likely not your problem because you have a freq response dip vs audible noise, but i'm just throwing it out there....

Best of luck.


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## jayhawk785 (Nov 10, 2009)

No, I wired the lights as well--and given they are separate circuits, would they even interfere? 

The subs are actually on a different circuit, I can run an extension cord to my outlet to test that theory if I dont find any problems with them individually. They are both on a hospital grade outlet surge protected. Living in florida you really can't take any chances (lightning strike capital of the world it seems).

Im going to do some more graphs at lunch--I'll re-run emo-q, test that and then test each sub individually. not sure there would be time for much else (but my boss is gone today so we'll see)


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## Aujan (Feb 13, 2011)

>No, I wired the lights as well--and given they are separate circuits, would they even interfere? 

If the separate circuit is on the same side of the panel as the lights, it can. The idea is to have audio
and lighting on a separate opposite phase of each other, so that if hum gets introduced into the stream
of your lighting, it phase cancels on the bus to your audio feed. It's a standard procedure in pro audio.
Not sure how often it gets done in home theater. Like I said, just a though. Most likely not your problem.

Best of luck.


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

jayhawk785 said:


> I can't seem to figure out the 60-70hz dip.


Well, I’m sure that big opening in the wall to the left of the screen isn’t doing anything good for you. Probably a combination of that and the subs being so closer to the center of the wall than the corners. Still, the dip is fairly broad, which indicates it might respond to equalization.

Regards,
Wayne


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## jayhawk785 (Nov 10, 2009)

I've been attempting to equalize it, but even boosting it in the sms-1 I don't see it flatten out much if at all. With both subs on there seems to be some cancellation. With one on the drop is less, but not by much. 

That space to the left usually has curtains covering it, when watching a movie. not sure if that will help or not, figured the waves would pass right through either way. It's also just a foyer, it doesnt open up much passed that.


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## jayhawk785 (Nov 10, 2009)

Also, to add-- i moved the right sub to the right corner, the way its facing now, and also steered it to the center of the room. Neither seemed to help that dip.


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## gdstupak (Jul 13, 2010)

If you try boosting 60hz with the eq and the actual sound level does not go up, makes me think your subs are working against each other at 60hz (depending on your crossover settings, the fronts may be working against your subs).
Everytime I re eq my system, it takes me hours to get it all to play well with each other. Each of my 2 subs has it's own eq so that helps alot.


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

jayhawk785 said:


> That space to the left usually has curtains covering it, when watching a movie. not sure if that will help or not, figured the waves would pass right through either way. It's also just a foyer, it doesnt open up much passed that.


Unfortunately, a curtain will make no difference (i.e. it’s no substitute for a “real” wall). Nor does the small size of the opening. Any opening will have an effect on response, especially one near a corner and near the subs themselves. My gut feeling is that the main culprit is a bad interaction from the two subs being at separate locations and therefore at different distances from the opening.




> Also, to add-- i moved the right sub to the right corner, the way its facing now... Neither seemed to help that dip.


Did you try measuring them separately, not in tandem? If you can get a good measurement from one of the subs, co-locating them would be the best bet (but admittedly not terribly visually appealing in your room). Another location you might try is in front of the right speaker (i.e., under the picture closest to the screen).

Wayne


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## jayhawk785 (Nov 10, 2009)

my wife is big on things being symmetrical, if i tell her I have to move a sub to that wall, she'll likely slap me. I can try it to see if it helps, but i doubt I'll get to move it there 

I can try collocation, but i figure that would defeat the overall purpose with response smoothing across seating area?


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## gdstupak (Jul 13, 2010)

Have you tried different phase settings?


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## jayhawk785 (Nov 10, 2009)

Yes, phase 0 / 180 on either side - both phases same 0, both 180, rotating either or--dips increase or improve slightly. Right now I think i have them about as close as its gonna get. lol


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## John White (Mar 29, 2011)

What your room dimensions?

- john


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## jayhawk785 (Nov 10, 2009)

room dimensions are tricky, since it opens up to other spaces--not sealed off.

The room space is 23x16, then there is an opening at the front that is 8'x8' and goes up about 15' --from the back of the room, there is an opening to the kitchen/eat-in/living room in the back of the house. So, probably another 45'x16' or so, then hallways etc.


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## John White (Mar 29, 2011)

Yes, those dimensions are a lot to swallow. Still, from the picture I haven't seen any serious treatment.

Also, how many different points in the room were measured. See what happens when you move the mic front and back. Hopefully that null will clear up, but who knows what else you'll find.


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## jayhawk785 (Nov 10, 2009)

I have 4 boxes with 6 panels 2x4' - 2" 703 on the way. I plan to do 2 4" corner traps in the front, one in the rear corner, 4 panels on the back wall 2" thick. And some on the peak in the ceiling. I'll play around with the rest. We'll see what happens.

the dip at 60 lessens depending on where i measure. the seats are 1/3 or less toward the front of the room... who knows. I'll see how the acoustic treatments work.


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## John White (Mar 29, 2011)

For what it's worth, 4" with space behind it (like straddling a corner) is a minimum for fiberglass. Best to use the remaining boxes for other corners such as the wall ceiling corner in the rear. Otherwise you won't get much of an attenuation of that 60Hz null. In addition you will only decrease your decay time in the higher frequencies while the lower peaks go unchecked.


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## Lumen (May 17, 2014)

jayhawk785 said:


> I did initially, but tweaked it around a bit. Anything I did in the eq, did not seem to matter... results always seem the same?


First an FYI... my UMC-1 does not have any firmware updates applied, so it may behave differently from yours.

That being said, the UMC-1 should let you change speaker level and frequency response after every EMO-Q run. Make sure that you save the run to one of the three available memory presets, and that you assign that preset to the appropriate source using the INPUT SETTINGS menu.

However, I've been unable to tell a difference in sound when making manual changes to speaker distance for a given EMO-Q preset. I've read that the UMC-1 only _appears_ to accept manual distance changes to a preset. Instead, it internally stores the distance results until reset by another run. My having read it doesn't make it true, and neither does repeating it; but I'm just trying to help.


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## Lumen (May 17, 2014)

opssign:

To the moderators:

I just realized I replied to an "expired" thread. This is my first forum membership, and would not have known better except... Yesterday I was browsing the forum and came across a post where a member was politely reminded that's a no-no :nono: 

I promise to be more careful. I'll understand if these two posts don't count toward my quota for the giveaway.


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