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8th order design challenge


KiKaZz74

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I been looking at the Bose Acoustimass design and from what I can see this is the outcome.

with Qts=.42, Vas=.46 ft^3, Fs=56[/size]

you should get[/size]
V1= .68 ft^3 Fb1=78.85 Hz[/size]

V2= .35 ft^3 Fb2=39.77 Hz[/size]

V3= 2.98 ft^3 Fb3=Fs=56 Hz[/size]

F3Lower= 36 Hz[/size]

F3Upper= 87 Hz[/size]

bandwidth= 51 Hz[/size]

That's all well and good... but can you extrapolate the calculations?

That's all well and good... but can you extrapolate the calculations?

Here ya go.

http://www.diysubwoofers.org/talkshop/messages/1308.htm

I'll post up more links as I see them.

Forgot this one.

http://www.diysubwoofers.org/cgi-bin/talkrec.cgi?submit=lt&fid=f1&msg_num=15225

b_350_20_692108_381007_FFFFFF_000000.png

Krakin's Home Dipole Project

http://www.stevemeadedesigns.com/board/topic/186153-krakins-dipole-project-new-reciever-in-rockford-science/#entry2772370

Krakin, are you some sort of mad scientist?

I would have replied earlier, but I was measuring the output of my amp with a yardstick . . .

What you hear is not the air pressure variation in itself

but what has drawn your attention

in the two streams of superimposed air pressure variations at your eardrums

An acoustic event has dimensions of Time, Tone, Loudness and Space

Everyone learns to render the 3-dimensional localization of sound based on the individual shape of their ears,

thus no formula can achieve a definite effect for every listener.

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that's why id go with a isobaric push/pull 6th order I wish my amp didn't have a subsonic on my MB QUART amp

that's not an easy one lol Steve Tryed one awhile back And ditched it an went ported. If you can pull it off that would be bad ass. I would like to see any if these enclosures built an tested.
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Yes, I do know that a 4th order is a ported box. I didn't realize it was because of the rolloff slope. I don't think people understand that, then. Why would anyone want a subwoofer with an 8th order rolloff slope? Just for SPL competition? if you had no subsonic filter, maybe that would be handy. But any amp today has a subsonic filter. My personal choice is to extend low frequencies as far below tuning as possible without over excursion or unloading of sub.

An "8th order" would have a retardedly small bandwidth but have enormous gain/efficiency. If you could do it right, it'd be an SPL monster.

Incidentally... if you also add a crossover to your 4th order (or whatever) you add an order. Add a 2nd order crossover to your ported box and voila'... you now have a 6th order and you're cool.

An 8th order's rolloff would be 24db above and below tuning. Not 48db either way.. LIke... a 6th is 24db per octave below tuning but only 12db above tuning.

So why doesn't anyone use 8th or higher in extreme vehicles if they seem to be so good?

And could you please explain the orders and roll offs in more general terms?

Also anyone have a list like I posted a ways back of all the details of the boxes?

Great info from what I can understand. :) thanks guys

My SPL to SQ Build Log

Vehicle:
1997 Dodge Dakota Ext Cab 4x4 2009 Dodge Journey SXT
5.2L V8 Magnum 3.5L V6
Stock Alt

Equipment:

Headunit- Alpine CDE-147BT

Mids/Highs Amp- JL Audio G6600 Class AB 6 Channel

Sub Amp- Hifonics BRZ1700.1D @ 2 Ohms Taramps DSP3000.1D

Sub- Hertz Hi Energy 12" HX300D SounDrive SDA3 12

Tweeters- Rockford Fosgate Power Series Silk Domes Hertz Hi-Energy

Mids- Dayton Audio Reference 4" Full Range Drivers 

Midbass- Silver Flute 6.5" Hertz Hi-Energy 6.5"

Processor- MiniDSP 2x4

RCA- 6 channels of SounDrive HF series

Wire- EB Flex 2/0

 

-Member of Team SounDrive

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the only reason I can think that people don't use them is cus they don't no how to build and tune and or just don't wanna blow expensive subs now I cant really help on the octaves and junk but id also like to no

[media][/media]

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An eighth order has three chambers. All three are vented. With the front and rear chambers of the sixth order vented into another chamber.

8tripbp.gif

Just saying you can make one as a dual chamber so that external port on the resonance chamber would be moved beside the sub along the center wall and the resonance chamber would no longer exist.

zr2usasig.jpg

Yeah, it's slower than your bowel movements.

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It takes rocket appliances to know how to make an 8th order...

Avalanche

Alpine Type S comps

Alpine Type S 10''

Alpine MPR-F300

Alpine MRX-M50

Mechamn 270

XS Power d3400s



 

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