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PLS HELP! Is my sealed volume calculation correct? (Read 3628 times)
soundwave
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PLS HELP! Is my sealed volume calculation correct?
11/07/10 at 19:09:49
 
Ive been reading the wo support forum pages and am unsure of the required sealed wedge volume for my 29" by 36" by 13.5" WO. I just want confirmation from the wo pros before I fire this thing up. I explain what calculations I came up with below and want to know if its correct.

I also wanna add that I am attempting to use this WO for a mobile dj setup for small sized venues. I own two mackie srm450 version 1's that need a subwoofer BADLY to help improve the sound. HOPEFULLY!

The driver I have ordered has been recommended by some. Here is the link:

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=295-110

Now I have been reading that I need to "model a regular 4th order single reflex box to determine the rear (sealed) chamber," so I went to this online calculator:

http://www.colomar.com/cgi-bin/4thorder_proc

and came up with these results:

1) Speaker Parameters

        Diameter:  10.00 (inches)
             Qts:   0.31
              Fs:  41.10 (Hz)
             Vas:   1.72 (cubic feet)
                =  48.69 (liters)
               S:   0.70 (response curve - .4 thru .7)


2) 4th Order Bandpass Cabinet Parameters

Lower 3db Rolloff:  35.00 Hz (F3 Provided by user)
High 3db Rolloff: 130.54 Hz (Calculated)

      Sealed Box:   1.01 cubic feet
                = 1742.60 cubic inches
                =  28.56 liters

      Ported Box:   0.32 cubic feet
                = 559.53 cubic inches
                =   9.17 liters

Tuning Frequency:  67.59 Hz

So I have to make the sealed wedge volume 1.01 cubic ft. , after  calculating in speaker and brace volume displacement, CORRECT?? Am I right?

As far as the ported box part goes, there is no ported box section on the wo, its like a horn...I mean there is no tube to port it. So I dont know how to use that figure.

What is tuning freq?

Looking at the pdf specification paper for this woofer, do you think it will perform well as a subwoofer for my app, because lower frequencies for hiphop and dance music is what I am after. Or should I have purchased a SUB woofer?

I plan on connecting from my dj mixer aux out, to an old numark 10 band eq [lower the high and raise the lower freqs], then output to a qsc, behringer, or mackie fr type of pa amplifier that puts out 250 rms at 8ohms per channel.

This is my attempt to improve my dj setup on a budget! Im looking at $160 for the 2 drivers and prob will spend atleast 200 for a good used amp. I don't think Ill need a crossover, I hope not!

ANY thoughts on this would be awesome. The party is going down this 19th, and I am so excited to hear what the WO will do.
Wink

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dank
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Re: PLS HELP! Is my sealed volume calculation correct?
Reply #1 - 11/08/10 at 12:16:14
 
I don't know if anyone has ever tried a ported rear chamber on a wicked one...I doubt it.  If anyone ever did, it probably didn't work very well or we would have heard about it.  I'd stick to the plans and with the series II speakers you will be fine.

With your DJ gig, be sure to allow setup time to play with sub location.  It can make a HUGE difference.  If you can setup in a corner and fire the wicked one into the corner (and you have the right room, and your lucky, and the moon phase is right) you can fill the room with the most wonderful bass you've ever heard.  Also try firing it into the back wall, then on its side down low, then vertical...don't just assume that pointed at the audience is best.   Good luck.

Dan
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ZYGI
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Re: PLS HELP! Is my sealed volume calculation correct?
Reply #2 - 11/10/10 at 01:34:19
 
Soundwave,

Build the WO to the plans and place the driver where it shows in the plans, the 295-110 works perfect in this position.

As far as the ported end, the port is the slot where the box opens into the flare. Making it a little narrower than the plans, reduces the upper end cut off freq. while mounting the driver with the magnet facing the port will lower the response of the sub, it will be a little peaky but at a lower freq. which IMO isn't a bad thing.

I would use a crossover, even if it was a passive crossover.

ZYGI
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soundwave
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Re: PLS HELP! Is my sealed volume calculation correct?
Reply #3 - 11/10/10 at 03:17:33
 
Yo thanks guys for the help.

DANK: I did read about how sub placement is important and I will try to find best location.. Also, maybe I confused you with my long post, but I am not trying to port the sealed chamber, I was referring to how the front slotted parts of the wicked one, which kinda are the ports, do not apply to the online calculators for 4th order single reflex booboo. Or maybe I just dont understand it.[This stuff gets really confusing, and I am the type of dude that strives for excellence.] I just wish I clearly understood how to calculate the sealed volume for this driver, so that I get the best optimum performance...

When you click on the link for this driver there is a review about some dude who used these for a WO but had to decrease the sealed volume... Someone please tell me how much the sealed volume must be.. that would be AWESOME. Grin

ZYGI: The wo will just need to be throwing the low end freq's. Should I flip it? I thought flipping it is for full range and higher freq's?

Would there be a possibility of causing damage to the drivers if using the eq as a crossover? The eq offers +/- 15dB adjustments. This is all I have....

Guess what just arrived? The parts express order! Those "woofers" are branded eminence made in the usa! They feel and look like they are going to hit really hard. Im so excited but will wait for tomorrow to finish the wo up. [ I actually started attaching a driver to a baffle, and as I was screwing it in, the dewalt slipped and almost punctured the surround! Lips Sealed I better wait for tomorrow and take my time doing this.]

Im sooooooooo excited.

ALSO here is a sketch of the 15" cab I will do next. I did one a long time ago and that mofo rattled my teeth and was shaking the foundation of my house. After about 4 minutes the sub was destroyed.

I cant imagine what a 15" driver from parts express would be like.....

LATERS!!!

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Snapshot_2010-11-07_03-32-57.jpg
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opnly_bafld
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Re: PLS HELP! Is my sealed volume calculation correct?
Reply #4 - 11/11/10 at 00:00:15
 
Undecided
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« Last Edit: 01/01/11 at 00:44:17 by opnly_bafld »  
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soundwave
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Re: PLS HELP! Is my sealed volume calculation correct?
Reply #5 - 12/16/10 at 21:38:04
 
I ALMOST FORGOT TO PAY MY RESPECTS!. EVERYONE HERE DESERVES A RESPONSE SO HERE IT IS AND SORRY ABOUT THE LATENESS.

I must say, the sub adds so much more to the party sound..... WAAOW! I am very satisfied with the results and even though I wired it ghetto with an eq instead of a real crossover, the improvement it gives two mackie srm450 active speakers is freegin AWESOME! My sound now is just right. Not too crazy and not too weak. However I think some 15" wo subs would be even more awesome.

I went from my aux output from my mixer into an old 10 band numark eq. All 480hz on up turned down and the lows adjusted up. Then the eq output into a used qsc rmx 1450 which I purchased on craigslist for 143 bones.

I spent around 3hunid total for this subwoofer addition. Im happy with the results. However a real crossover would add even more improvement. Thanks decware Cheesy

Next time its gonna be about some 15" wo subs, watchout!

HAPPY HOLIDAYZ! Wink

P.S. If this wo was in a ride with an amp that could bring full clean power like my qsc does, it would be ... I cant think of a good word. It would be nuts insane the vehicle would probably explode. lol.
IT WOULD HIT HARD AZ HAIL!!!!!!!!!!
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lunatech
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Re: PLS HELP! Is my sealed volume calculation correct?
Reply #6 - 12/29/10 at 11:08:33
 
I used these Dayton's in a WO-36 and wrote the review in Parts Express you referenced. I made my sealed chamber slightly smaller by blocking it in about where the brace is located. This was not a scientific operation! Trial and error.
I called Steve because after building the WO, my bass was mushy. He recommended I experiment with the sealed chamber volume. I only used my ear for measuring, but am very happy with the results. I also mounted the woofer on the backside of the baffle by mistake. This may have led to my  need to play with the chamber volume.
End result is a great sounding sub! Keep it crossed no higher than 90Hz, preferably lower. It gets used everynight hard in a DJ rig and has proven bullet proof so far.
THe girls tend to like to stand on top of it and dance like its a mini stage or something! No problem, this box can take it.
As the previous member suggested, there is several db to be gained if you fire it at a the back wall about 6-10 inches away, or corner load it.
If you like building Steve's stuff, you might try the Pro-12's. My friend who runs the DJ rig for his business sold his Mackie's after trying the Pro-12's.
I'm not knocking Mackie's, they are good sounding, but they don't beat Decware speakers. Just my opinion.
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« Last Edit: 12/29/10 at 11:12:23 by lunatech »  
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soundwave
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Re: PLS HELP! Is my sealed volume calculation correct?
Reply #7 - 01/23/11 at 03:14:14
 
Hey bro thats awesome that you connected back to this place I didnt expect really to hear from the person who left that review on the p ex website!

Bro, you know thats alot of room to subtract from the chamber.  I actually am running the wo just like the plans calls for, no adjustment or mod to the sealed chamber. I was like screw this and just wanted to get the wo done already and was over the calculating thing. It freegin hits.

I threw it in my 2004 camry which I just copped and it hits. I think its a lil too much for me actually and the thing weighs a grip. I think its burning too much extra fuel just to have low end capabilities like this. Also the metal is rattling, etc.  Might take it out or research making a 6" mini wo or something if it bumps and not to expensive. If it was lighter itd be awesome, but fahgitaboutit itz HEAVY! Fits perfectly though.

Im gonna post some pics of it asap here to share with the homies.

Luna- What crossover setup u running? Active, passive, or ghetto like mine?

LATER buds!
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Bart_West-VL.
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Re: PLS HELP! Is my sealed volume calculation correct?
Reply #8 - 01/23/11 at 06:53:07
 
I don't know what a ghetto crossover looks like  ::) , but you should at least put a large coil in each speaker cable.

Any pics to share?
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soundwave
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pics for my friends!
Reply #9 - 01/27/11 at 02:19:45
 
Heres what a onthebudget ghetto xover setup might look like. Also JUST finished changing the internal volume. HOPEFULLY I did it the same as the other member. Did I put the board in the right place bro or did you put yours straight accross? I hope thisll work cuz its clamped now, just wanted to finish it already.

Ill wait for the your responses before I tighten the 40 freegin screws for the lid. Should I try it like this or do you think this is too much volume to subtract?

ANY and all thoughts appreciated please.

ALSO the handles do not make it THAT much easier to maneuver it, id say it makes things 50% easier that I thought it would because you cannot carry the box with two people, each person grasping a handle, because the box still is slamming against you legs and plus the way the handles swing out to be used. Im sure theres a better locations to put these but I didnt want to put them on the sides because I like to be able to stand it up and flat on whatever sides for the parties. OK guys enjoy these.

shuwks! I have to change the file sizes now to upload them for you. Thisll take another 10 minutes. Ahhhhh. Arrgh. Rrooof!
wasnt that bad took 3 minutes Im just lazy sometimes. LATES.

ALRIGHT SCREW THIS I CANT UPLOAD IT IS SAYING
" ERROR 217 kilobytes and cannot be uploaded." !!!
HEY I TRIED BROZ, IT SAYS MAXIMUM ATTACHMENT SIZE 250KB. Mine is 217kb so it should be good. Ill post em up later if someones explains how to.  >:( Angry
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soundwave
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Re: PLS HELP! Is my sealed volume calculation correct?
Reply #10 - 01/27/11 at 02:21:04
 
asdhjkl
had to try one last time NOPE.


An Error Has Occurred!



180 kilobytes and cannot be uploaded.
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Bart_West-VL.
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Bart_West-VL.

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Re: PLS HELP! Is my sealed volume calculation correct?
Reply #11 - 01/27/11 at 17:37:54
 
I load my pics to http://tinypic.com/ and link to there in my reply.
I didn't even know you could upload to this site, o wait, you can't as it seems, lol. Wink
just kidding

you could mail the pic to me, I'll post it for you.
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« Last Edit: 01/27/11 at 17:40:14 by Bart_West-VL. »  
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