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4th Order Build Opinions

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=141326
Printed Date: March 28, 2024 at 1:10 PM


Topic: 4th Order Build Opinions

Posted By: praisewaves
Subject: 4th Order Build Opinions
Date Posted: May 26, 2016 at 1:06 PM

posted_image

just wondering what everyone thinks of my build schematics, does everything look right, any clue what the box will be tuned to, is my math right, ratio okay. any opinion will be appreciated. the build is in an 02 jeep liberty and it consists of 4 mofo 15s wired in parallel at .5 ohm and a 10,000 watt edge

MOFO-154X
EG1-10000D


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Cfrittswallace



Replies:

Posted By: praisewaves
Date Posted: May 27, 2016 at 4:08 AM
I'm using three-quarter inch MDF the floors will be one layer thick the walls and ceiling will be two layers thick and the baffles and portwall will be three layers thick also the subwoofers will be reversed. This is my first 4th order build and my first big build I have had two 12s two 15s and four 15s all prefab boxes so all and any opinions will be appreciated because I'm starting the 2x4 frame tomorrow it'll take me about 2 months because of my income so I have time to change things up if need be

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Cfrittswallace




Posted By: praisewaves
Date Posted: May 29, 2016 at 12:11 AM
posted_image

ive got the jeep framed in. 68 views and no replies. . . i hope some people comment an share opinions but if not ill get it done either way. thanks for viewing and once again feel free to comment all opinions are welcome good and bad

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Cfrittswallace




Posted By: DYohn
Date Posted: May 30, 2016 at 9:28 AM
I assume you are building this to compete?

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Posted By: praisewaves
Date Posted: May 30, 2016 at 9:50 AM
Yes I live in Tennessee thought so I don't think there is any here but I'm willing to drive

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Cfrittswallace




Posted By: DYohn
Date Posted: May 30, 2016 at 11:53 AM
When you are finished be sure to get it metered and let us know what frequency you burp.

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Posted By: praisewaves
Date Posted: May 30, 2016 at 4:37 PM
For sure, I think I'm gonna go with 4 18 psi platform 1 1000 watts instead same amp thou

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Cfrittswallace




Posted By: praisewaves
Date Posted: June 04, 2016 at 3:19 PM
posted_image

got the walls up, coming along slowly but surely

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Cfrittswallace




Posted By: praisewaves
Date Posted: June 13, 2016 at 7:59 AM
posted_image
ends capped off and outer walls painted, gotta say everything is coming along great but at the same time lol its all harder than i thought it would be anyways ill keep yall posted and in the mean time as always feel free to comment and post


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Cfrittswallace




Posted By: praisewaves
Date Posted: June 16, 2016 at 4:25 AM
Man I must say I'm really bummed and disappointed with this form almost 400 views and only 2 posts from other people I was expecting a lot more response but o well I will keep posting anyways maybe as it goes on people will chime in more

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Cfrittswallace




Posted By: the12volt
Date Posted: June 16, 2016 at 5:28 PM
Your build is looking nice, but don't put too much weight into the number of views. Search engine spiders account for most of those and there are many visitors that are not members that cannot reply.

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Posted By: praisewaves
Date Posted: June 17, 2016 at 8:24 PM
Thanks for the encouragement.

Well I've done the math today and a lot has changed I originally planned for 52ft^3 12.5 sealed and 39.5 ported making it an 3:1 4th order with 4 15s, after a lot of change in plans, working with the shape of the car, deciding to make the battery/amp space bigger, and my final decision being to go with 3 18s rather than 4 15s after displacement I now have 33ft^3 9 sealed and 24 ported. a heavy 2.5:1 ratio

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Cfrittswallace




Posted By: praisewaves
Date Posted: June 19, 2016 at 12:46 AM
posted_image
My original build schematics 4 15s

posted_image
New corrected and final build schematics 3 18s

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Cfrittswallace




Posted By: praisewaves
Date Posted: June 20, 2016 at 11:15 AM
OK so I really need some help here, someone that knows there stuff please help. I run my box with three 1800 watt platform 2 psi 18s on WinISDbeta (first time use) and I know what Hz and dB's are obviously but not really how to read them on a graph yet so can someone please tell me if this is good or bad or if I need to udjust somthing or if you need different info or more detailed or whatever

Gain Chart:
-3dB = 28Hz & 87Hz
0dB = 30.5Hz & 79.5Hz
11.7dB(Peak) = 52.5-55Hz

Phase Plot:
350-50 deg = 33-76Hz

SPL:
149-149.6dB(Peak) = 45.5-58.5Hz

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Cfrittswallace




Posted By: haemphyst
Date Posted: June 21, 2016 at 5:12 PM
Well, I can certainly say it's dramatically more than I'd ever even attempt... I'm a small sealed enclosure kind of guy, with the brute force and influence (aka BFI) method of powering a system into the desired curve.

I'm not a fan of bandpass enclosures, generally speaking, and I'm more of a SQ guy (thus the distaste for bandpass) but I respect you greatly for the effort you're putting into this system. So far, it looks good, too! I'd love to chime in other than this, but I've never even attempted to build a bandpass system. posted_image

Keep it up!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: praisewaves
Date Posted: June 21, 2016 at 6:20 PM
Thanks for the support man, I won't lie I am really nervous because I've never don't one this big or done a bandpass either but im taking my time and I've done ALOT of research. The farther along I get the better I feel about it thou so I've got good expectations

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Cfrittswallace




Posted By: praisewaves
Date Posted: June 24, 2016 at 7:57 PM
posted_imageposted_image

got my port built today i decide on 20x26x7.75 making it tuned at 48.5Hz, i know i keep changing everything but id rather change my plan a thousand times and get it right at the end. plus im new to the big builds so im learning and correcting as i go

also i know the port is alittle premature considering i dont have my port wall yet but im pretty broke right know and this is what i could afford to do this week so its better than doing nothing

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Cfrittswallace




Posted By: praisewaves
Date Posted: June 24, 2016 at 8:09 PM
posted_image

heres my gain chart from winISD i never could get help so i just tryed to tune it where it is as broad an even as possible, for a noob in the 4th order builds i think im doing pretty good im very confident in my buid =) as always keep viewing and ill post more as soon as possible

-3dB=27.79Hz&84.65Hz
0dB=30.33Hz&77.47Hz
11dB=45.54-51.07Hz

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Cfrittswallace




Posted By: praisewaves
Date Posted: July 04, 2016 at 8:17 PM
posted_imageposted_imageposted_image

got the port wall in =)!!!! starting to close in and look more complete

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Cfrittswallace




Posted By: haemphyst
Date Posted: July 21, 2016 at 12:15 PM
Still looks really good! Like I said, more than I'd attempt, but you're doing a bang-up job!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: praisewaves
Date Posted: July 25, 2016 at 11:44 AM
Set back in the project for about a month, motor went out, gonna cost 1300-2000 to replace just wanted to let y'all know

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Cfrittswallace




Posted By: haemphyst
Date Posted: November 13, 2023 at 7:32 AM
praisewaves, how'd this ever do? I know it kinda got dropped, but I still come back occasionally, and look through some of the dangling threads... It was looking really good!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."





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