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Old 24th October 2008, 11:18 PM   #1
Thawach is offline Thawach  Thailand
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Default Problem with this database

hi my guys


today i think of my friends. i have a little problem with the database.
i want this driver to build PC sub. i may be use 2 drivers in 1 box.
Gm and Ron E i want your helps. do u forget me or not? okay guys i see the x max. it's only 2 mm. i use bass box to simulate. please u see. lower than 147 hz it's over than the limit(2mm). guys it seem to be mistake with this database. i want to know that i think.is it alright?

GM now i want to build a little Pc sub.because i want to sing a song.
okay james blunt thai cover version.do u know? Gm i found my
new pretty girl last week.i feel happy cause that i want to sing. Luka comes here,now i'm happy with your red box.i've seen your red box.

my friends, your reply i thanks a lot.

Thawach


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Old 25th October 2008, 01:18 AM   #2
GM is offline GM  United States
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Greets!

I do not know why there should be such a discrepancy since the math to calculate excursion should be very accurate by now, but in Hornresp it hits 2 mm around 165 Hz and 220 Hz in LspCad Pro, though the simple BoxPlot 3.07 puts it around 110 Hz, so quite a range.

Bottom line though is that 2 mm does not go very low at 50W with a small driver.

GM
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Old 25th October 2008, 09:09 AM   #3
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Quote:
Originally posted by GM
I do not know why there should be such a discrepancy since the math to calculate excursion should be very accurate by now, but in Hornresp it hits 2 mm around 165 Hz and 220 Hz in LspCad Pro, though the simple BoxPlot 3.07 puts it around 110 Hz, so quite a range.GM
Hi GM,

The discrepancy is probably due to differences in the ways that the programs calculate the air load on the diaphragm. I suspect that LspCAD Pro and BoxPlot 3.07 may use simpler models than Hornresp when determining acoustical impedance.

Hornresp diaphragm displacement results are identical to those predicted by AkAbak.

Kind regards,

David
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Old 25th October 2008, 04:27 PM   #4
GM is offline GM  United States
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Greets!

Well, never having done any really accurate excursion measurements I don't know how accurate any of the programs are and unfortunately lost in a fire the Altec nomograph they developed from extensive anechoic measurement to compare them to, but considering all the hard data that's been available for decades you'd think that all programs with any pretense of accuracy would be fairly close to each other.

GM
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Old 25th October 2008, 07:37 PM   #5
Thawach is offline Thawach  Thailand
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GM and David thanks for come to my thread.!!
Gm i only surprise with this limit.with this drivers i had done it before. in the past i only knew this valve(qts,fs,vas)for i built.
GM,i'm 44 years old. go to the past with my old prject.do u remember
1980-1990? okay that time i built like this. the woofer was up and the
tweeter was down. that time was hit!! sorry! my surround is not good. i think to repair again. Gm in the past i didn't have any program and no has BSC when i built. i did with my math and mesure again. it's very difficult for built the xo. i was try and try.ok guy with sucessful.
the port was tune about 36-40 hz. i did not use vanish because it was fallen from my stand. the veneer skin cannot repair. Gm the sound is good. it likes AR classic 8 that i heard. but the midrange sound is better than.i think because 6 1/2" driver is less than ar 8". Gm i increase my volume was high. no problem with it. yersterday i saw the database that i'm surprised with the x max.

regards
TW
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Old 26th October 2008, 03:46 AM   #6
GM is offline GM  United States
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You're welcome!

Yes, I'm 62, my kids are only a few years younger than you.

The vast majority of drivers have a rising rate suspension, so combined with a falling motor strength beyond Xmax the result is that they will play well beyond it before bottoming out, though if you are paying attention you will hear them flatten out on deep bass notes.

GM
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Old 27th October 2008, 06:35 PM   #7
Thawach is offline Thawach  Thailand
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GM "You're beautiful"!! with 62y u work well.
but i think that i'm on this broad until 100y. Are u on with me? sorry! my englang(english+language) isn't good. i'm afraid when they ask this but my answer is that thing. now i have many projects. but i would not show my friends. because it may be not beautiful but it can only listen. Gm u give me many suggestions. more than this word"thanks" that i can say
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