posted
man i thought i understood the design, but the more i read the more i got confused
if i have a manufacturer spec box at 3.25 with a 5"x16" port, is the 3.25 the whole box size which has to be split into a 2/3 ratio? or do i add to the 3.25 size?..."IF" i add to the size, do i figure the port for 3.25 or for the total added net volume of all chambers ?
somewhere on here it said to figure for 2 ports, but there will be 3 total
the ports, if i figure 2 ports in 3.25 then for 3.25 it will end up doubling the length to 32" for 2 port tubes...
which way to go, man i swear something was mis stated somewhere on here and threw me off...
Posts: 378 | Registered: May 2001
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posted
wow....looks like most of the old peeps that have posted in the past arent around to see this but me....well....i'll answer the question of how do u design one...or the rule behind them....ok...here is an example box
u have to do everything on a 1/3 2/3 split when u go and figure out the ports u have to figure it as one big box and generally u want a bigger box than a normal ported box so if u wanted a box to be 5 cubes total u have to make one side 1.33 cubes and the side where the sub goes make that 3.33 cubes so lets say that i want each port to have 24sqin of port tuned to 35hz so when u figure it u figure it as a 5 cube box with 2 24sqin of port so after calculations u get 17 inches long....when u go to make the ports u make 3 of them...even though u figured for 2....u need 3....u have put one in each chamber and then use the third one to connect the 2 chambers....put that port in a 1/3 2/3 split as well.... oh yeah....and remember....be very accurate with measurements and calculating displacements of the ports and sub....these boxes are touchy
i hope i helped....if there is any confusion or more questions....just ask...thats y this post is here.....
posted
I wanted to experiment with a horn but after those 26 pages my subconscious keeps yelling 'ABC, ABC, ABC...' This is my January project for sure
-------------------- SPL=Knowledge+open mind RFR 3115 (2) JBL BP1200.1 (4) Waiting to be measured... www.sounddomain.com/id/spled Posts: 502 | From: Lima, Peru | Registered: Jul 2001
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posted
Interesting thread.,of course my grand kid will want to read this thread and it`s one hundred plus pages.
-------------------- You are what you read. Un happy with your life? Change what you read. Change what you are. Posts: 206 | From: Nobodys damn business but mine | Registered: Jun 2002
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posted
Bringing this back up.,I notice that in large boxes .,the one octave spread causes the cone to flop at certain frequencies., I.e. given a resonance at 30 hertz and the second one at 60 hertz.,the cone will flop.,in a very large box.,at 45 hertz. Solution.,make a box with three resonance points.,30 hertz.,45 hertz and 60 hertz.,goodbye cone flop., Ok., but how do I make an ABC box with three resonance points? In other words.,a three chamber box.
-------------------- You are what you read. Un happy with your life? Change what you read. Change what you are. Posts: 206 | From: Nobodys damn business but mine | Registered: Jun 2002
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quote: so if u wanted a box to be 5 cubes total u have to make one side 1.33 cubes and the side where the sub goes make that 3.33 cubes
so am i the only one to catch this oops, he meant 1.66/3.33 - it's a 2 to 1 ratio, and i think thats after the displacements are removed, there has to be 1/2 as much cubes' on one side as the other
Posts: 13 | From: ireengswesco | Registered: Jan 2003
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posted
"Solution.,make a box with three resonance points.,30 hertz.,45 hertz and 60 hertz.,goodbye cone flop.," guess you would have to go 1 1/2- 2 1/4- 3 cubs and put a port in each-and thru to the other ones-or mabe just thru to the 3cube
-------------------- I needed a sub Fast as my car
found it - DD 3512/9512 bass that hits like jet lee- quick, clean, and accurate - sound as clear as it gets - Posts: 107 | From: The Start | Registered: Dec 2002
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posted
Thank you.,can any one else verify that to make a three chamber abc box.,the ratios are 50 percent.,75 percent and one hundred percent?
-------------------- You are what you read. Un happy with your life? Change what you read. Change what you are. Posts: 206 | From: Nobodys damn business but mine | Registered: Jun 2002
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Honestly, the idea is a little drastic. ABC already pushes the limits of vented technology. There is nothing to gain from using a tri-chambered ABC except a huge waste of time and reduced cone motion at high frequencies(whoopie).
Posts: 768 | From: Ottawa, On, Canada | Registered: May 2000
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posted
Hey, I was really hoping if someone could help me make plans to make a box somewhat like this one:
It is for a Resonant Engineering 12se. The site says
"Ported: 2 cuft on up(tuned to 35Hz for daily apps)"
I was wondering if i can just build one port into one side of the box. I would be willing to paypal someone 10 bucks or something if they make me plans and the dimensions are so the box will fit in the trunk of a 94 Thunderbird and its tuned to 35hz like the site suggests. Either post here or email marcus@gr8vertical.com if you want to help
-------------------- System in my 1997 Opel Corsa Lite Hatch : RFX8340 HU RF Punch 800a4 RF WhiteWolf 1F Cap AudioControl THREE.1 DynAudio 7" Component Set RF Punch HX2 10" http://www.sounddomain.com/id/boomshaka Posts: 726 | From: South Africa | Registered: Apr 2001
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posted
Using 1 RFP2818 sub and 4 4" ports 15.4" long tuned to 32.4Hz. 1st Chamber with Sub and 2 ports subtracted = 4.42 ft^3 2nd Chamber with 2 Ports subtracted = 2.21 ft^3
With 3rd pair subtracted I get 4.26 ft^3 on Chamber 1 and 2.13 ft^3 on chamber 2. (Port length is devided in 3, 1/3 in 2nd chamber and 2/3 in 1st chamber)
Is this all worked out right ?
-------------------- System in my 1997 Opel Corsa Lite Hatch : RFX8340 HU RF Punch 800a4 RF WhiteWolf 1F Cap AudioControl THREE.1 DynAudio 7" Component Set RF Punch HX2 10" http://www.sounddomain.com/id/boomshaka Posts: 726 | From: South Africa | Registered: Apr 2001
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-------------------- System in my 1997 Opel Corsa Lite Hatch : RFX8340 HU RF Punch 800a4 RF WhiteWolf 1F Cap AudioControl THREE.1 DynAudio 7" Component Set RF Punch HX2 10" http://www.sounddomain.com/id/boomshaka Posts: 726 | From: South Africa | Registered: Apr 2001
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