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Finally, some action... (Read 18000 times)
Bob in St. Louis
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Re: Finally, some action...
Reply #45 - 06/15/06 at 12:00:51
 
I'ts cool to see your name written by someone, it means they remembered you, that you may have made an impression. But geez bassboy!  I'd hate to be remembered by "The Driver Destroyer" Cry  LOL

Hey Jet, just throw the damn thing in a bathtub full of water (just don't do the 120v thing  :-/)

Bob - thanks for remembering me - in St. Louis

....carry on fella's,... good discusion going.  ;D Wink
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« Last Edit: 06/15/06 at 12:19:47 by Bob »  
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Adrian D.
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Re: Finally, some action...
Reply #46 - 06/15/06 at 12:53:01
 
ok guys, let's set things straight with the inverted/normal mounting.
it matters in direct radiating designs (ie ported, sealed and back-loaded horns). but it doesn't matter in designs where the port is responsible for 100% of the total output.
J_rock explained it nice. the air molecules vibrate.
as far as i'm concerned, mounting inverted shouldn't apply a-simmetrical pressures on the cone, because the whole structure is simmetrical.
one thing that worries me is that the magnet is very close to panel f. i don't know if i should worry about that. the air can move under the magnet.
what worries me is air movement just under the cone. using a 2inch baffle and because the sound splinter has such a big spider, i can bearly squeeze my finger through the round cutout and the basket.
i think i should ask steve...i wonder if he will answer my pm...
how many of you in for "send steve a pm and settle the mounting problem" ?
J_rock, i want to ask :
since you mounted all of your subs in the db inverted, did any fail (mechanically)? did you push them beyond their thermal limits ?
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Lee in Arkansas
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Re: Finally, some action...
Reply #47 - 06/15/06 at 12:58:42
 
Adrian, my first thought would be to cut the lower baffle slightly larger, but ask Steve.

My DB's are put off, yet again, due to my car blowing it's water pump. 2 nights a 6-pack of Fat Tire, and it's still not fixed.
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60ndown
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Re: Finally, some action...
Reply #48 - 06/15/06 at 13:18:45
 
all my dbs had the magnets in the sealed end, all of them were able too handle lots of power and sound great. i think the thermal thing is an issue if your going to play test tones or really heavy bass for long durations (1/2 hour straight or more) but for me most of my listening is @ moderate volumes with strong bass and occasional 'cranking'.adrian reverse your sub in a few weeks and let us know if it sounds different? i think the magnet being very close to panel f might cause noise (air rushing past) @ high volumes?
and molecules vibrateing? pfffft! im gonna stick with my subs fireing forward untill steve d tells me it makes no difference.
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Adrian D.
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Re: Finally, some action...
Reply #49 - 06/15/06 at 13:24:55
 
pm sent to steve. now just pray that he answers.
since it's raining outside i may just put the magnet in the sealed chamber today.
my guess is that it won't play as low as now if i keep the insert as it is now.
i'll remove the bottom lid to see how the air moves past the magnet.
60, isobaric mounting poses the same problem because one of the subs has the magnet in the vented part.
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Lee in Arkansas
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Re: Finally, some action...
Reply #50 - 06/15/06 at 13:53:38
 
find out your subs vas (is that the right one?) and move your baffle accordingly to make up that difference.
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Adrian D.
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Re: Finally, some action...
Reply #51 - 06/15/06 at 13:55:39
 
some estimates as to what effect the mounting has: since the sub displaces rougly 0.09 cf, it would be similar to moving the insert lower by 1 inch. covering the port changes the whole deal.
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Lee in Arkansas
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Re: Finally, some action...
Reply #52 - 06/15/06 at 14:27:31
 
So go like, 1/2?
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Adrian D.
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Re: Finally, some action...
Reply #53 - 06/15/06 at 14:53:10
 
i'm really undecided about reversing it. the magnet obstructs  air movement over panel f. that can't be good.
i just checked the mounting depth of J_rock's subs. it's identical to the mounting depth of mine. but J used a triple 3/4" baffle. so in his case it should be a 0.25" increase in the distance between panel f and the magnet.
???
EDIT :
good 'ole 25hz tone helps....
removed the bottom lid and i let the 25 hz tone rip. first with about 50w. i couldn't feel a diffrence in air movement between the part under the magnet and the 'unrestricted' part. i noticed now that the metal plate on the bottom of the magnet is conical. and it gets smaller at the edge. so, taking a better look, it seems like it's not that bad.
i increased the power until the insert vibrated too bad. only noise i could notice was coming from between the boxes. none coming from the driver and the pats that worried me.
waiting steve's answer, but my dad told me something really smart : "do you like how it sounds? yes? then leave it the way it is !"
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« Last Edit: 06/15/06 at 15:35:59 by adi_ro »  
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J_Rock
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Re: Finally, some action...
Reply #54 - 06/15/06 at 22:56:15
 
I place all my DB subs with the magnet structure in the ported enclosure.  Mainly because I have never had a problem with a mechanical failure in a sub driver.  Always the VC melting or something before the VC exits the gap.

I re-read the white papers also, and it is like 40 and up says, the magnet is to be put in the sealed chamber.

Its interesting to note the original driver they used is a Kicker Competition C-10 by stillwater designs.  I happen to have 2 of these in the 12 inch version.  And they are the only drivers I have tested in a DB and the recommended sealed and ported enclosures.  And the DB did outperform just like the article stated.

I have tried other 10" subs in their recommended enclosure against the DB, and the DB always wins.  

2 more things to edit in:

1.  The pictures of the insert on the website and in the plans do show the driver's magnet inside the ported section of the Box.

2.  Perhaps I have not had any trouble with mechanical failure because todays drivers are much more rebust than those of yester-year.  I mean, perhaps mechanical limits were indeed the limits back then, whereas thermal power handling is the main limit nowadays.
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« Last Edit: 06/15/06 at 22:58:20 by j_rock777 »  
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bassboy
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Re: Finally, some action...
Reply #55 - 06/16/06 at 00:00:37
 
Like I said, I don't have the plans, but I swear I thought I saw a picture somewhere with the VC in the ported side.  I was wondering how I could have got so confused...

But like I also said, I spent a lot more time looking at the WO than I ever did the DB.
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Adrian D.
Ex Member



Re: Finally, some action...
Reply #56 - 06/20/06 at 18:27:53
 
Steve's answer :
Quote:
I would try it as is first, then flip it around and see if there is a significant improvement.  If there is, then cut the second baffle larger so it can breath a bit more.

Steve

i guess it didn't clarify the magnet in sealed vs magnet in vented discussion Sad but it gave me some piece of mind.
btw, the insert still isn't bolted in and sealed but i like it the way it is now. with the insert just at the top of the port.
the thing with the mechanical limits was that the vcs were rubbing against the t-pole because of uneven pressures in the box. but there is a possibility that the subs bottomed out...
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J_Rock
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Re: Finally, some action...
Reply #57 - 06/21/06 at 03:53:01
 
[quote author=Adrian D.  link=1147870641/45#56 date=1150824473] i like it the way it is now. with the insert just at the top of the port.. [/quote]

This is the same spot both of my DB's were sounding best with the Infinitys.
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Adrian D.
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Re: Finally, some action...
Reply #58 - 06/21/06 at 05:49:18
 
kinda weird. i said i was going to spend a lot of time tuning but i tried only 2 positions.  :-/
i just need to borow a digital cam to take some pics.
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Adrian D.
Ex Member



Re: Finally, some action...
Reply #59 - 07/28/06 at 19:20:54
 
seems like there is a chance the 'monster' will get covered in leather. i found out i have a neighbour that makes leather belts and jackets. so i hope he'll be able to help me.
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