Laser alignment rig for my Orcas

bainjs · 4229

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Offline bainjs

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on: November 25, 2012, 11:21:31 AM
here's a laser alignment rig I made to pinpoint my Orcas.  All it is, is a $3 laser pointer centered in a hole drilled in piece of wood.  

I think I like it best with both of them aimed at the center of my chair's headrest. The surprising thing is how far they were off center before I used the laser.  I blame it on my astigmatism.


« Last Edit: November 26, 2012, 08:42:09 AM by bainjs »

Joel Bain


Offline Clark B.

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Reply #1 on: November 25, 2012, 02:42:05 PM
Orcas with friggin' lasers!



haha! 

No seriously, this is a cool solution.  Some rooms need a pretty precise toe-in, and depending upon how close the listening position is, a few degrees can make a difference.  Some rooms (like ours) are good with no angle in or out (parallel stance) with the speakers 9 or so inches away from the front wall.

What I'd really like to see somebody do is to "the chair."  ultra near field listening on super well broken in Orcas powered with 45s.  Kindof like the speaker equivalent of the AKG K1000's. 

-Clark


Offline bainjs

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Reply #2 on: November 25, 2012, 02:57:01 PM
Mine are about 10 feet away.  For my layout and personal preference, this works well for me.  Just a few degrees one direction or the other makes a difference.  Like laser beams!


Joel Bain


Offline fullheadofnothing

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Reply #3 on: November 25, 2012, 02:58:18 PM
Clark

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Offline Doc B.

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Reply #4 on: November 25, 2012, 03:56:40 PM
I think this would get you in the ballpark, but a measurement mic and software might give you a better idea of relative distance of the two speakers by comparing arrival times.

Dan "Doc B." Schmalle
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Offline bainjs

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Reply #5 on: November 26, 2012, 01:01:13 AM
Hmmm, you got me thinking now.  I have a standard PC mic.  Would that work?  How about the software, any suggestions that's reasonable?

Joel

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Offline Doc B.

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Reply #6 on: November 26, 2012, 04:44:33 AM
You might need to go for something with a fairly well understood frequency response like the cheapo Behringer measurement mic. We use some software called ETF to do our measurements, which I bought so long ago it is installed on my 2002 vintage laptop. So there may be newer, possibly even free software that works better. The reason I still use ETF is that we calibrated it and PJ's B7K mic with a 1/8" capsule against Bob Hodas' state of the art SIM system, so we know the frequency response results we get with that rig are pretty close to what he gets.

Dan "Doc B." Schmalle
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Offline rif

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Reply #7 on: November 27, 2012, 02:57:33 AM
Very cool! 

I'm curious, how did you get the laser housing aligned with the jig? And the jig aligned to the speaker cabinet? I know I don't have the woodworking skills to do it, are there any tricks?

This is a sacrilege for many, but many inexpensive AV receivers have audyssey multieq built in that calculates distances, crossover, phase.


-david


Offline bainjs

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Reply #8 on: November 27, 2012, 07:54:42 AM
I just nailed two squared pieces of wood together to make a 90 degree and cut the width to the same as the Orca.  I placed small rubber feet on it to keep it from slipping off the speaker.  I then drilled a hole in the center of the board just big enough to fit the laser pointer.  I've drilled enough holes in the past to be pretty accurate.  If you have a drill press, that would be even better.

With the rig sitting on the speaker, I press the on button and adjust the speaker accordingly. I'm sure it's not super precise but it's better than my previous method.  ;)

Joel Bain


Offline Natural Sound

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Reply #9 on: November 27, 2012, 11:00:12 AM
You could cable tie the laser to a t-square. Maybe some stick-on felt on the bottom to protect the finish on the speakers.

(http://img.ehowcdn.com/article-new/ehow/images/a02/0s/ot/use-t-square-800x800.jpg)



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Reply #10 on: November 29, 2012, 04:38:44 PM
I second Doc's reply about timing. No doubt, aiming your speakers correctly is important. It is also recommended that the distance from each speaker to listener's ear(s) be equal. I learned this from setting up the Carver C-9 sonic hologram unit. With or without it, the sound was greatly improved in almost every way. After that, every system I set up had a ritual of speaker positioning.