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post #31 of 40 Old 03-30-2013, 06:28 PM - Thread Starter
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Yup

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post #32 of 40 Old 03-30-2013, 07:40 PM
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That looks to be a lot higher Q than .65, but not knowing the driver or alignment I can't render an opinion.

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post #33 of 40 Old 03-30-2013, 07:47 PM - Thread Starter
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CSS trio 12 sealed in 75L. Can't remember of it was 75L but pretty sure. Well stuffed to.

Doesn't really matter. Actually kind of nice knowing I can put more LT onto the low end than I was planning. Thanks for taking a look though. Maybe I modelled wrong...

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post #34 of 40 Old 03-30-2013, 08:26 PM
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If the specs are accurate 60L net gives a Q of .7, with no hump. I suspect stuffing the cab over damped it. F3 looks right, response above 70Hz doesn't, and over damping can kill the midbass.

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post #35 of 40 Old 03-30-2013, 08:40 PM - Thread Starter
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You think I over stuffed it? I suppose that could be it.

How about the steep roll off though? Much steeper than 12db/oct.

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post #36 of 40 Old 03-30-2013, 08:59 PM - Thread Starter
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Impedance matches the model ok. A little higher impedance actually smile.gif


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post #37 of 40 Old 03-31-2013, 06:29 AM
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Quote:
Originally Posted by tuxedocivic View Post

You think I over stuffed it? I suppose that could be it.

How about the steep roll off though? Much steeper than 12db/oct.
You only stuff when you want to lower Q. If Q is already low enough you just line the cab. The rolloff from 40 to 20 looks fine. Below that I'd question the accuracy of the testing hardware.

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post #38 of 40 Old 03-31-2013, 08:38 AM - Thread Starter
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Hmm, you're right about 40 to 20. The mic is an ECM8000 calibrated by cross spectrum to their highest standards. I suppose it could be the Dayton T amp I used. Convenient for outdoor work. I'll try a near field indoors with a higher end setup when I have a chance and see if that's a problem. Thanks!

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post #39 of 40 Old 03-31-2013, 08:41 AM - Thread Starter
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There was visible excursion way down at least at 5hz. 2hz starting frequency though.

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post #40 of 40 Old 03-31-2013, 10:21 AM
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Quote:
Originally Posted by tuxedocivic View Post

Hmm, you're right about 40 to 20. The mic is an ECM8000 calibrated by cross spectrum to their highest standards. I suppose it could be the Dayton T amp I used. Convenient for outdoor work. I'll try a near field indoors with a higher end setup when I have a chance and see if that's a problem. Thanks!
I have my HolmImpulse calibrated with the power amp in the loop. It's a simple affair, you just have to be sure the power amp is set at unity gain so it doesn't toast the sound card input.

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