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Re: My 2nd attempt at graphing my room response?
bridgman #141410 07/01/06 12:21 PM
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Hi John, thanks for the input, I'll have to read it a few times to try to follow. Sorry about the dot color, for whatever reason, I could not figure out how to change the color in Adobe Photoshop, I would click on a different color, but it would always turn out gray, go figure.

Anyway the theater wall portion is setback 6 feet from the rest of the room, so the short wall on the right side of the screen is about 6 feet. The back wall is 15ft wide and my screen is 10 feet wide, so that leaves me 2.5ft on each side for my m60's. The ceiling is 9ft tall.

I have my m60's pulled out about 8" from the back wall. I guess I want to be careful in pulling them out to far as the the primary (ear) listening position is about 13ft when sitting in the center recliner, I don't think you want all 3 sides of the triagle to be the same, according to Axiom.

During the first graph, as the pictures show, the m60's where about 1ft from the left and right walls, toed in just slightly. The 500 was just a bit to the right of the left m60, so it was about 2.5ft from the left wall (right below the screen edge).

The second graph I had the m60's closer togethor so they are close to the edge of the screen but didn't interfere with the picture from the projector. So I would say they were about 2ft from the left/right walls. The 500 was centered right below the screen, below the VP150. The picture does not show it, but I now have the VP150 mounted on the wall, right below the screen.

I have not done a graph yet with my current 500 position of being in the left corner, about 6" from the left AND back wall. The 60's are still 8" from the back wall and right next to the screen.

I thought about some side treatments for the first reflection points, not sure if that would help any. Jakeman and Royce73 gave me some great DIY links in the other treatments post from BrotherBob. As far as corner traps, I have room on the right side, but since the 500 is in the left corner I would not have room unless I mount the trap above it on the wall? Or, I could move the 500 back to the other side of my left m60, similar to how BrotherBob has his 600 on the other side of his right m80.

I do have a pool table between the theater seating area and the bar now, so I'm sure that will have some effect on the overall room response.


M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85


Re: My 2nd attempt at graphing my room response?
SirQuack #141411 07/01/06 01:46 PM
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I can't see that it was mentioned here, so I'd just like to point out that the distances from the speakers and the back and side walls should not be the same. A ratio of at least 1 : 1.3 (measured from the front of the cabinet) is generally recommended to prevent wavelength re-enforcement.

Nice room, btw.

-Jon


Axiom M60ti Hsu VTF-2 Mk2 NAD C320BEE NAD C542 Systemdek IIX Cables by Unity Audio
Re: My 2nd attempt at graphing my room response?
SirQuack #141412 07/01/06 03:19 PM
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>>The back wall is 15ft wide

Aha !! That probably helps explain why the 38 Hz peak is the biggest one. I suspect that if you stuck the EP500 in the middle of the wall rather than the left hand side that would take down the 38 Hz peak. At first you would think you had less bass, but after a while you might notice that all the rest of the bass is just as strong, particularly the deepest bass, and it's actually the emphasis around 40 Hz that has been toned down.

This is all in theory, of course. We have to keep telling ourselves that.

>>I guess I want to be careful in pulling them out to far as the the primary (ear) listening position is about 13ft when sitting in the center recliner, I don't think you want all 3 sides of the triagle to be the same, according to Axiom.

Agreed. My dim understanding is that if you make the angle too wide the stereo image "collapses" at some point. I have observed that myself, although I don't fully understand why it happens.

>>I thought about some side treatments for the first reflection points, not sure if that would help any.

If I am visualizing the dimensions properly, you probably don't have a first reflection point on the right hand side. Putting anything absorbent at the first reflection point on the left would probably improve the imaging even more, although it doesn't have to be fancy foam.

>>I do have a pool table between the theater seating area and the bar now, so I'm sure that will have some effect on the overall room response.

Seems to me that you should be able to build a pretty substantial bass trap into the underside of the pool table


M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
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Re: My 2nd attempt at graphing my room response?
MarkSJohnson #141413 07/01/06 03:31 PM
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Just read this thread for the first time...

Mark, you have not submitted your location to the board, or else I'd look up a forensic psychiatrist in your area and put you on his radar... LOL

Maybe you watch a lot of Law and Order and/or CSI? Time to step back from the dark side, man!


Bears, beets, Battlestar Galactica.
Re: My 2nd attempt at graphing my room response?
medic8r #141414 07/01/06 03:49 PM
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>>Mark, you have not submitted your location to the board, or else I'd look up a forensic psychiatrist in your area and put you on his radar...

You haven't seen Mark's room response curve. I think he is handling the situation extremely well, all things considered

[EDIT] Randy, I'm still trying to decipher the Denon manuals but IIRC you can use the equalizer manually, not just via AutoEQ, although you lose the ability to adjust the center frequencies of each equalizer band. I don't suppose the manual EQ has a band around 38 Hz, does it ? If so, then you might want to try knocking that peak down via manual EQ.

Playing with the room responses (ie moving the EP500 to the center of the back wall) will probably still work better overall but if you are getting tired of moving boxes around the EQ thing would sure require less bending and lifting

Last edited by bridgman; 07/01/06 04:00 PM.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8
Re: My 2nd attempt at graphing my room response?
bridgman #141415 07/01/06 11:49 PM
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JP:
I list my location as Concord, NH. But all of the so-called "professionals" in my area invariably throw their hands up in the air after a session or two!

John:
Someday, I'm going to offer you the $38.12 I have in my wallet right now to help me figure out my room!


::::::: No disrespect to Axiom, but my favorite woofer is my yellow lab :::::::
Re: My 2nd attempt at graphing my room response?
SirQuack #141416 07/02/06 12:10 AM
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axiomite
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>>Randy : The second graph ... The 500 was centered right below the screen, below the VP150.

>>John : I suspect that if you stuck the EP500 in the middle of the wall rather than the left hand side that would take down the 38 Hz peak.

Hmm. Think I missed something. The second graph did have the EP500 in the middle of the back wall. I'm surprised that didn't have more effect on the 38Hz peak -- is there any chance the side wall to the right of the screen is very light construction compared to the rest of the walls ?

Mark -- All I need is beer and free time


M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8
Re: My 2nd attempt at graphing my room response?
bridgman #141417 07/02/06 03:41 AM
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Our foundation walls are called "Ice Block". Instead of a traditionally poured foundation, these forms have foam on the inside and outside, and then 8" of concrete is poured in the center voids which are rebar strengthed. These are so much more efficient and many builders are using them.

Anyway, all the exterior walls have the iceblock, except for the walkout area, which is 2x6's. So behind the screen is iceblock with drywall and so is the left wall. The right 6ft wall is framed with 2x4's and has drywall.

I think I will try graphing the room one more time with the sub in the left corner and compare all three graphs. Right now I think I'm getting the best sound I've heard with the 500 in the left corner and the 60's as close as I can get them without interfering with the screen.

By the way, got the pool table all felted and had my first game with my 7 yr old tonight, if he keeps practicing he will be as good as his old man.


M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85


Re: My 2nd attempt at graphing my room response?
SirQuack #141418 07/02/06 06:49 AM
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Quote:

By the way, got the pool table all felted and had my first game with my 7 yr old tonight, if he keeps practicing he will be as good as his old man.


... by the middle of next week. *rimshot*

Bren R.

Re: My 2nd attempt at graphing my room response?
BrenR #141419 07/06/06 10:53 PM
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Ok folks, I just finished my third graph and am looking for advice/comments compared to my first attempts above. For this test I moved the 500 to the left corner on the left side of the left m60. I ran the realtraps test tones in Direct mode on the receiver with a crossover set at 80hz and mains set to small. The Radio Shack meter was placed in the center lazy boy at ear level, which would simulate my main listening position for music. Thanks in advance for any comments...




M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85


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