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| Re: JTR Growler vs. EAW LA400: Review: Measurement Data [message #317033 is a reply to message #317032 ] |
Sun, 27 April 2008 15:20   |
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 Phil Lewandowski
Messages: 205
Registered: March 2007
Location: Cleveland, OH |
Has No Life |
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| Ivan Beaver wrote on Sun, 27 April 2008 16:16 |
The only thing that I would change about your test is the level and measurement distance.
With any loudspeaker when you are up close, you will get artificial "gain" at some freq due to the relative size of the box and the distance measured.
If you can, try using 28.3v (as measured at 60Hz) and a distance of 10M. The neighbors might no like that test however  .
The end result will be very close to the same db wise,due to the 20db rise in applied level and 20db reduction in distance. You just take the physical size out of the equation. Remove the variable-so to speak.
You also need to be far away from any reflective surface of a decent size.
Other than that, given the tools you had to work with, it looks like you approached it well.
I agree, good REPEATABLE data is important, not just under "special" circumstances or conditions or unkown conditions.
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I knew you would chip in!! Thanks Ivan!! Ya, that is the one thing after I started measuring that I realized I could have done. Because I have heard you talk about that and at Danley, using that way!
Thanks for the suggestions!
Phil
"It is good to be Alive!!!"
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| Re: JTR Growler vs. EAW LA400: Review: Measurement Data [message #317045 is a reply to message #317044 ] |
Sun, 27 April 2008 16:32 |
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Phil Lewandowski
Messages: 205
Registered: March 2007
Location: Cleveland, OH |
Has No Life |
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| Ivan Beaver wrote on Sun, 27 April 2008 17:23 |
Just one thing you do need to remember however. Unless you have a pretty good SPL meter, your measurements are really only good for the units you measured-in the same way, under the same circumstances. While not absolute, they are comparitive.
Less expensive SPL meters often do not have a flat response, so your readings could be a little bit off, when comparing to loudspeakers not measured under the same circumstances.
But you should be "close".
It is excerises like the one that you went through that really get you thinking and "pushing" for more answers, and questioning some specs that are provided.
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Gotcha, that makes sense. I definitely didn't use a high quality SPL meter!
Thanks Ivan!
"It is good to be Alive!!!"
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| Re: JTR Growler vs. EAW LA400: Review: Measurement Data [message #317079 is a reply to message #317066 ] |
Sun, 27 April 2008 18:10 |
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Phil Lewandowski
Messages: 205
Registered: March 2007
Location: Cleveland, OH |
Has No Life |
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(Deleted and re-posted)
[Updated on: Sun, 27 April 2008 18:16]
"It is good to be Alive!!!"
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