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ErinsAudioCorner

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hardisj

hardisj

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I contacted Klippel about this specifically. They said it would only work for the one speaker (or similar size/type) but due to difference in directivity alone that I could not use the NFS measurement as a 'room calibration' of sorts.
 
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hardisj

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After having shared the above post and spending the day conducting said tests, I am seriously considering overhauling my method for off-axis measurements. Right now I am spinning the mic about the baffle of the DUT. Easy enough. But doing it 10x today for the 0 - 90 degree measurements got old. Fast. I built a turntable a couple weeks ago but decided against it. Now I'm going to play with that idea more tomorrow.

I also now need an 8 foot ladder because that 6 foot ladder ain't gonna cut it when trying to lug a speaker up and down it and hoisting even the little bookshelves over my head to reach the 8.5 foot pedestal height. So I'll be shopping those tomorrow; hopefully someone has some on sale.
 

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I also now need an 8 foot ladder because that 6 foot ladder ain't gonna cut it when trying to lug a speaker up and down it and hoisting even the little bookshelves over my head to reach the 8.5 foot pedestal height. So I'll be shopping those tomorrow; hopefully someone has some on sale.
Stairs.... Need stairs made-welded from 1" diameter steel pipe and put small wheels-casters underneath so you can roll it around. Maybe some day. :D

Oh i just had a idea.. a scaffolding so you can stand on the platform and work up there in safety and comfort.
FH02OCT_SCAFFP_01-2.jpg
 

Doodski

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Exactly!


I wish I owned a bucket lift. Then I could use it for both speaker testing and Christmas lights! :D:D
If you have a used buy and sell like Kijiji you might find some gyproc installer or painter selling his scaffolding for cheap. I see them from time to time for sale.
 
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hardisj

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All kidding aside, I've been looking at TV monitor lifts. Something like this:
https://amzn.to/2xBr9Ew

Thinking that I could attach the base to my turntable (so I can spin the DUT) and then add a platform to the top to place the speaker on. So, ground -> stand -> turntable -> lift -> platform -> speaker. It says it can support weights up to 150 lbs which is certainly achievable. I could put it on a platform maybe 5 feet feet off the ground, load the speaker to the stand, then electronically lift it to the measurement position. If the load height was the minimum (30 inches) then I could get an extra 3.5 feet.

If I knew for sure that $250 for this piece would do exactly what I want and hold up to the testing I plan to implement it for then I would be happy to spend the money. But this is the world of "buy it and try it" and that becomes costly when you're having to "modify" things to get them to work the way you want them to. Problem is, these things are built for TVs and no need for a platform at the top so I'd have to rig something up there. I don't know if this kind of device could be modified in the way I want.

Time is money and important to me. I don't want to spend an hour on put-up and take-down for every test. So that's why it is so important for me to find a setup that is easy to assemble and disassemble. Not to mention consumption of space when it is disassembled.
 

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A variation on this?

untitled.png


Speaker platform instead of chair, sliding counterweight on the other end or pneumatic or hydraulic piston for lift assist(a car jack, maybe). Pivot height to suit.
 
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hardisj

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A variation on this?

View attachment 59642

Speaker platform instead of chair, sliding counterweight on the other end or pneumatic or hydraulic piston for lift assist. Pivot height to suit.


Possibly. Would have to rig up a pinion system to lock it in to place. But it's an idea, nonetheless. Thanks for the suggestion.
 
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hardisj

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Well, I might as well let this turn in to my full on "brain dump".... I'm sure you guys don't mind and maybe you can even offer some suggestions here.

What I need is a way to lift a speaker high off the ground. I want at least 8 feet speaker platform height. Why? Because Rambo! That's why!

I also need the speaker to be able to rotate on a DIY turntable I built (see graphic below for example).

I need to be able to afford it. Unless anyone out there feels like donating their stimulus check to this fund; and I don't think anyone loves speaker data that much.


This caught my eye: https://www.harborfreight.com/1100-lb-high-lift-transmission-jack-33615.html
Something like that; maybe not that exact model.
Min height = 44 inches. Max height (lifted) = 70 inches.
I could put it at min height, bolt a platform to the top of it + a 2 foot speaker stand that sits on the turntable. At min height I could just sit the speaker on top of the stand, then use this to raise the speaker another couple feet. I'd still have to get on a a smaller ladder to set the speaker to the top platform since the min would be 44 + 24 = 68 inches but it's better than climbing up 6 feet and hoisting a speaker over my head to a height of 8.5 feet like I did today. Plus, no kidding, when I came in today my elbow popped (bmx injury; surgery when I was 17) and I thought "man, if I were ever hoisting a speaker and that happened, that speaker would be toast". I laugh saying it. But I wouldn't laugh if it happened. :D :eek:

Testing little bookshelf speakers is fine and dandy. I'm just trying to be proactive for when/if I ever test some behemoth speaker(s).


index.php
 
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jhaider

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After having shared the above post and spending the day conducting said tests, I am seriously considering overhauling my method for off-axis measurements. Right now I am spinning the mic about the baffle of the DUT. Easy enough. But doing it 10x today for the 0 - 90 degree measurements got old.

That sounds super tedious. If continue you do that, maybe you could speed things up a little (?) by building a compass jig and spacer (dowel, PVC pipe, etc.) to keep the distance constant without constant remeasurement.

That still requires a large known level radius.

I built a turntable a couple weeks ago but decided against it. Now I'm going to play with that idea more tomorrow.

Given the height from which you're measuring, automation would quickly pay time dividends. Maybe @Matthew J Poes has some feedback. I'm lazy - I measure on my deck and stick to 6' high because I view modal+transition region response as a room correction matter - so the camera head works fine for me. :)
 
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hardisj

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That sounds super tedious. If continue you do that, maybe you could speed things up a little (?) by building a compass jig and spacer (dowel, PVC pipe, etc.) to keep the distance constant without constant remeasurement.

If you look at the picture I posted earlier you can see a couple dog leashes. ;) :D

But, IF that were the final version I would do what I have for my driver testing setup which is a piece of PVC.


Curious, have you tested a large floorstanding speaker on your stand? I worry about stability with such a top-heavy item on a speaker stand pole.
 

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Curious, have you tested a large floorstanding speaker on your stand? I worry about stability with such a top-heavy item on a speaker stand pole.

No, I've only measured standmounts. The heaviest speakers I'm likely to put on are JBL LSR708P and LSR708i, because I'm interested in comparing them and have both.
 
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hardisj

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No, I've only measured standmounts. The heaviest speakers I'm likely to put on are JBL LSR708P and LSR708i, because I'm interested in comparing them and have both.

Ok. If I knew I would only ever test bookshelf speakers this would be a lot easier. But over-building for the future is adding some more complexity to this task.
 

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Ok. If I knew I would only ever test bookshelf speakers this would be a lot easier. But over-building for the future is adding some more complexity to this task.

After reviewing one large speaker (Tannoy XT 8F) I decided I never wanted to try to measure one again. Which, since IMO that's where the value added in a speaker review really comes from, means no future large speaker reviews.
 

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Well, I might as well let this turn in to my full on "brain dump".... I'm sure you guys don't mind and maybe you can even offer some suggestions here.

What I need is a way to lift a speaker high off the ground. I want at least 8 feet speaker platform height. Why? Because Rambo! That's why!

I also need the speaker to be able to rotate on a DIY turntable I built (see graphic below for example).

I need to be able to afford it. Unless anyone out there feels like donating their stimulus check to this fund; and I don't think anyone loves speaker data that much.


This caught my eye: https://www.harborfreight.com/1100-lb-high-lift-transmission-jack-33615.html
Something like that; maybe not that exact model.
Min height = 44 inches. Max height (lifted) = 70 inches.
I could put it at min height, bolt a platform to the top of it + a 2 foot speaker stand that sits on the turntable. At min height I could just sit the speaker on top of the stand, then use this to raise the speaker another couple feet. I'd still have to get on a a smaller ladder to set the speaker to the top platform since the min would be 44 + 24 = 68 inches but it's better than climbing up 6 feet and hoisting a speaker over my head to a height of 8.5 feet like I did today. Plus, no kidding, when I came in today my elbow popped (bmx injury; surgery when I was 17) and I thought "man, if I were ever hoisting a speaker and that happened, that speaker would be toast". I laugh saying it. But I wouldn't laugh if it happened. :D :eek:

Testing little bookshelf speakers is fine and dandy. I'm just trying to be proactive for when/if I ever test some behemoth speaker(s).


index.php

Shouldn't the speaker baffle align with the edge of the spinning tray?

If so, will this damage the mechanism?
 
D

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Shouldn't the speaker baffle align with the edge of the spinning tray?

If so, will this damage the mechanism?
Well, obviously. He was showing that animation for effect. :)

A 6" bar stool replacement swivel is what I've used for a long time. That's heavy duty enough to support nearly all speakers and can be mounted in various ways depending upon the testing setup.

Dave.
 
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hardisj

hardisj

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Shouldn't the speaker baffle align with the edge of the spinning tray?

If so, will this damage the mechanism?

Well, first off, the picture I showed was for illustration only.

Second, the baffle should align with the center of rotation.
 
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