very newbie questions

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firedog

very newbie questions
« on: 11 Mar 2011, 06:09 am »
Hi-
Just got panels for the first time and am trying to find reflection points.

Questions: small room, one of my side walls is very short b/c that side has a large opening to an adjoining room.

1) When I look for the reflection points with a mirror, I don't have a place on the short wall where I see the front of the speaker in the reflection, I only see the side of the speaker in the mirror. So is this a reflection point?

2) Ceiling reflection point: I understand it's approximately midway between me and the speakers, and I should be able to see the speakers reflected in the ceiling mirror at that point?

3) Behind speakers (far wall from listening position): I understand I should put a panel (I have a 242 for this) on the wall horizontally between the speakers, approximately speaker height? Is this correct? Or would it be better to place the panel on a stand closer to the speakers? The speakers are only about 3 ft. from the wall behind.

Thanks for your help. I've already put Tri-Traps in the corners behind the speakers, and that alone has already improved things quite a bit.

When I finish setting things up I'll tell you how it sounds.

TomW16

Re: very newbie questions
« Reply #1 on: 11 Mar 2011, 03:27 pm »
Newbie answers are my specialty but I'll defer to the experts in case I'm off (newbie here too)  :D

Quote
1) When I look for the reflection points with a mirror, I don't have a place on the short wall where I see the front of the speaker in the reflection, I only see the side of the speaker in the mirror. So is this a reflection point?
  The short side wall will reinforce the bass frequencies that will be more omnidirectional depending on your type of speaker.  The idea is that each speaker should have similar surroundings so that each speaker will have similar sound (reinforcement or lack thereof).  It sounds like your higher frequencies, that are more directional, will not hit the short wall and, therefore, will not require you to treat the first reflection point there.

Quote
2) Ceiling reflection point: I understand it's approximately midway between me and the speakers, and I should be able to see the speakers reflected in the ceiling mirror at that point?
  That is correct.  If you ears are at the same height as your tweeters the first reflection point on the ceiling should be exactly half way between you and the speakers.

Quote
3) Behind speakers (far wall from listening position): I understand I should put a panel (I have a 242 for this) on the wall horizontally between the speakers, approximately speaker height? Is this correct? Or would it be better to place the panel on a stand closer to the speakers? The speakers are only about 3 ft. from the wall behind.
  I would treat the wall behind you first (wall furthest from the speakers) as the sound will travel past you, hit the wall behind, and then travel past your ears again from behind before hitting the front wall (depending on your speaker type).   You would obtain some benefit from treating the front wall (closest wall behind the speakers) because of the omnidirectional response of the bass frequencies but absorption must be thicker to affect the bass frequencies.

I'll hand this off to the experts now.

Good luck and have fun.

Tom
« Last Edit: 11 Mar 2011, 04:37 pm by TomW16 »

bpape

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Re: very newbie questions
« Reply #2 on: 11 Mar 2011, 03:37 pm »
Any chance of posting a rough sketch of the room so we can get a better feel for the layout?

Bryan

firedog

Re: very newbie questions
« Reply #3 on: 11 Mar 2011, 03:54 pm »
Thanks for your help.

I've replaced the bookshelves with floor to ceiling Tri-Traps.

I checked again, and the short side wall (where the opening is) doesn't have a true reflection point. If you move a mirror to the edge of the wall where the opening begins, you can see the full side of the speaker reflected in the mirror, but not the front (tweeter). On the other side wall there's a clear first reflection point on the wall (opposite the opening in the other wall) and I've placed a 242 there to deal with the first reflection on that side.

I've put 244's on the opposite wall that you don't see - the wall opposite the speakers.

So essentially I'm trying to figure out what to do with the 242's (I have 3). Ceiling is a bit problematic for me (have to move a light fixture), but can be done.

Thanks

« Last Edit: 11 Mar 2011, 04:58 pm by firedog »

bpape

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Re: very newbie questions
« Reply #4 on: 11 Mar 2011, 05:03 pm »
Left wall reflections opposite the opening is a good place. 

If you're sitting relatively close to the wall behind you, you could try a couple there just leaning temporarily and up on boxes to cover ear level.

Bryan

firedog

Re: very newbie questions
« Reply #5 on: 11 Mar 2011, 05:56 pm »
Thanks Bryan.

If I wasn't clear, I already have 244s on the wall behind me.

So I have Tri-Traps full length in the 2 corners behind the speakers (removed the shelving), and 244's facing the speakers from the opposite side of the room (behind where I sit).

I've placed one 242 at a first reflection point on the wall on the left in the picture.

I'm thinking at this point of putting one 242 on the first ceiling reflection point, and another horizontally below the window - between the speakers. Does this make sense? Is the ceiling a more important point than the wall behind the speakers for a 242? Or do you have another suggestion? Thanks again.


poseidonsvoice

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Re: very newbie questions
« Reply #6 on: 6 Apr 2011, 06:08 pm »
firedog,

Given where you live, are your walls (L, R, and ceiling) made out of concrete or drywall/gypsum board? Is the floor concrete, carpet over concrete, wooden floor or tile over concrete?

Anand.

bpape

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Re: very newbie questions
« Reply #7 on: 6 Apr 2011, 06:44 pm »
I've placed one 242 at a first reflection point on the wall on the left in the picture.

I'm thinking at this point of putting one 242 on the first ceiling reflection point, and another horizontally below the window - between the speakers. Does this make sense? Is the ceiling a more important point than the wall behind the speakers for a 242? Or do you have another suggestion? Thanks again.

That should be fine.

firedog

Re: very newbie questions
« Reply #8 on: 7 Apr 2011, 07:55 am »
firedog,

Given where you live, are your walls (L, R, and ceiling) made out of concrete or drywall/gypsum board? Is the floor concrete, carpet over concrete, wooden floor or tile over concrete?

Anand.

Hi-

Thanks Anand for the interest. And Bryan for the reply.

My walls and ceiling are concrete, the floor is tile over concrete. At this point I've put up all the panels except the ceiling one, which requires me to move the existing light fixture. Hopefully, that will be done tomorrow.

I can say that even without the ceiling panel, I'm very happy with the results. All of the hoped for improvements have occurred: tighter bass, generally more focussed sound, clearer detail, no more reflections off the back wall behind the listening point. That last problem is really a big one in a small room.

In short the GIK panels have been like a major upgrade to my whole system. Listening is much more enjoyable everything is much more musical sounding. Previously I'd used TACT DRC to achieve much the same effect, but I think I prefer the results with the panels, especially as the panels don't tie me in to any specific audio hardware.  I may try DRC again along with the panels, as several audiophiles have told me this gave them the best results. We'll see.