Using a laser for reflection points
skiroy
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10th January 2009
Old 10th January 2009
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Using a laser for reflection points

How do I place the laser on the speaker I am trying to locate its reflection points.Would I just lay it on the cone?I ask because when I lay it on the cone,the laser point hits behind me,when in my listening position.
But from everything I have read a reflection panel should be placed somewhere between the speaker and the listener's head.
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10th January 2009
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you don't need a laser.... that's just silly. You need a mirror. Wherever you can see the speakers in a mirror, when the mirror is flat against the wall, is a major reflection point - obviously. But bass traps are far more important.... reflections are easy to solve.
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10th January 2009
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Quote:
Originally Posted by skiroy View Post
everything I have read a reflection panel should be placed somewhere between the speaker and the listener's head.
Narco has the right answer. More here:

Early Reflections

And here:

How to set up a room

--Ethan
skiroy
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10th January 2009
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Originally Posted by narcoman View Post
you don't need a laser.... that's just silly. You need a mirror. Wherever you can see the speakers in a mirror, when the mirror is flat against the wall, is a major reflection point - obviously. But bass traps are far more important.... reflections are easy to solve.
But its a hell of lot easier to place a laser on the speaker cone and see where it hits then it is to figure out how to rig something where you can move a flat sitting mirror around on the wall from your listening position.
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Originally Posted by skiroy View Post
its a hell of lot easier to place a laser on the speaker cone and see where it hits
Probably not because you'd need to angle the laser to mimic the speaker's off-axis response. Much easier to use a mirror, I you can calculate the reflection point (area really) as shown in the Room Setup article I linked above.

--Ethan
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10th January 2009
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Quote:
Originally Posted by skiroy View Post
But its a hell of lot easier to place a laser on the speaker cone and see where it hits then it is to figure out how to rig something where you can move a flat sitting mirror around on the wall from your listening position.
Actually, you can use both.

Affix a mirror on the front of the speaker and sit in your sweet spot. Now take a laser pointer and point it at the mirror from the middle of your forehead.

Bob's yer uncle.


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10th January 2009
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Quote:
Originally Posted by skiroy View Post
But its a hell of lot easier to place a laser on the speaker cone and see where it hits then it is to figure out how to rig something where you can move a flat sitting mirror around on the wall from your listening position.

It's easier to sit down and have a coke but that will be as poor a solution to finding reflection points as the laser. ;-)

If you can't do it with a tape measure (understanding angles and stuff) use a mirror.


/Peter
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Quote:
Originally Posted by JusSumguy View Post
Actually, you can use both.

Affix a mirror on the front of the speaker and sit in your sweet spot. Now take a laser pointer and point it at the mirror from the middle of your forehead.
You're supposed to put in a smiley when you're joking! ;-)

For readers not understanding the joke, the idea useless.


/Peter
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10th January 2009
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Oh yeah, you hafta affix the laser to your forehead with some superglue.

Don't worry, it'll come off. tutt


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I'm sorry but I still don't know for sure if you're joking or not.


/Peter
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JOKE......
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Quote:
Originally Posted by JusSumguy View Post
Oh yeah, you hafta affix the laser to your forehead with some superglue.

Don't worry, it'll come off.
And then you can use the forehead pointer for typing as well.
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Quote:
Originally Posted by skiroy View Post
But its a hell of lot easier to place a laser on the speaker cone and see where it hits then it is to figure out how to rig something where you can move a flat sitting mirror around on the wall from your listening position.
why on earth do you think you need a LASER? It has no purpose here at all. First, how do you know the LASER is lined up with the speaker axis. Secondly, speakers are diffractive not directional... a LASER is very directional, heck, even a torch would be better. The whole exercise is pointless! The reflections on your right hand side, for example , will becoming from off axis reflections of the right hand speaker primarily. Sticking a LASER on top of a speaker will tell you nothing other than there is a LASER on top of your speaker.....
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put mirrors on the wall
affix a laser to the top of your head
point your head at the mirror and see if you can bounce the laser off the mirror and hit the speaker. If yes, replace that mirror with some panels.

Be careful not to set the speaker on fire.
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Quote:
Originally Posted by narcoman View Post
even a torch would be better



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skiroy
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11th January 2009
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Originally Posted by joeq View Post
put mirrors on the wall
affix a laser to the top of your head
point your head at the mirror and see if you can bounce the laser off the mirror and hit the speaker. If yes, replace that mirror with some panels.

Be careful not to set the speaker on fire.
Silly,but actually is a good idea.I may be ignorant but the mirror techniques seems hard for me to know where my reflection points are.I mean ,if I can see the speaker at all is that a reflection point?Do I have to see the the cone or any of the cabinet?
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If you can see the speaker through mirror, the soundwaves have equal path from speaker to you.

If you see the speaker at all, it is enough for reflections to happen, but if you can see the cones, they are probably even worse.

The laser thing sounds too much trouble, and misses the point that speakers emit sound in every direction, not just straight away from the cone.
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11th January 2009
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Quote:
Originally Posted by skiroy View Post
Silly,but actually is a good idea.I may be ignorant but the mirror techniques seems hard for me to know where my reflection points are.I mean ,if I can see the speaker at all is that a reflection point?Do I have to see the the cone or any of the cabinet?
Well my idea actually works, and it does technically meet the Mandatory Laser Requirement, but your eyes are sufficient. Put absorption wherever you can see the speaker. Cone/cablnet: you are talking a matter of inches. Put a little extra, it won't kill you.
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12th January 2009
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Quote:
Originally Posted by JusSumguy View Post
JOKE......

How come that is so obvious to me today!!


/Peter
#21
18th January 2009
Old 18th January 2009
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Quote:
Originally Posted by skiroy View Post
Silly,but actually is a good idea.I may be ignorant but the mirror techniques seems hard for me to know where my reflection points are.I mean ,if I can see the speaker at all is that a reflection point?Do I have to see the the cone or any of the cabinet?
YES!!! for crying out loud

a LASER is just light !! highly amplified and powerful, but still just light!!! If you can see a speaker in the reflection, then that is a reflection point!!

In fact - your LASER technique is completely deficient - if you shine a LASER on something (or a torch for that matter) you'll see the point of light hit a wall that ISN'T a reflection point, as well as those that are. Just use a mirror. It is in fact the ONLY way to do it visually.
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