Sean
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 649 Registered: Sep-04 | hey im aobut to get all the stuff i need to make that ABC box.. i was just wondering how the ports should be placed... like should i keep chamber 1 all the way to the left, ports combining chambers all the way to the back, and ports in chamber 2 all the way to the right... and make them spaced out evenly in height and have them in a straight vertical line? and btw thanks again soo much for your help |
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Gold Member Username: InsearchofbassPost Number: 2971 Registered: Jun-04 | I must not have saved my file i sent you can you post it and ill double check things before I answer |
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 662 Registered: Sep-04 | sean Gold Member Username: Insearchofbass Post Number: 2648 Registered: Jun-04 Posted on Friday, June 10, 2005 - 04:07 pm: his car=48wide 21 high 26.5 deep 4.66662 cf. first chamber ported at 20.0954 hz with 4 two inch id pvc ports 16.5 inches deep .15 port volocity at 800 rms 2.33331 cf. second chamber ported at 28.419 hz with 4 two inch id pvc ports 16.5 inches deep .11 port volocity at 800 rms space taken up per port .046142578125 cf. (.1845703125 cf. for each front chamber) ( .0928515625 cf. for each interior chamber with the ports evenly spaced between the two chambers) .5537109375 cf. space needed in box size over the 7.00 cf target to account for all port displacements .277421875 is cf taken up in chamber 1 and 2 4.944041875 gross chamber 1 2.610731875 gross chamber 2 24.00 wide by 15.5 high by 23 deep=4.9513888 cf this is the demensions of chamber 1 internal you must also add a .75 mdf wall dividing chamber 1 and 2 (so account for that) and place each 2 inch port one over the other height wise evenly spaced length wise between the two chambers this is for the interior ports 12.6875(11/16) wide by 15.5 high by 23 deep=2.61753110532407 cf only thing i need is the displacement for the subwoofer and ill add that into chamber 1 and were done these demensions are internal so add 1.5 inches to length width and height because well be using .75 mdf if i charted this box by theory right you should hit from to 20 hz to 55 hz after that you prob wont notice much except by cabin gain youll do four 2 inch ports on the front of each chamber 16.5 inches deep and four 2 inch ports internally as instructed above sean Gold Member Username: Insearchofbass Post Number: 2649 Registered: Jun-04 Posted on Friday, June 10, 2005 - 04:15 pm: sorry i realized the chamber measurements werent clear so here you go chamber 1.... 24.00 wide by 15.5 high by 23 deep=4.9513888 cf chamber 2.... 12.6875(11/16) wide by 15.5 high by 23 deep=2.61753110532407 cf " sean Gold Member Username: Insearchofbass Post Number: 2650 Registered: Jun-04 Posted on Friday, June 10, 2005 - 04:38 pm: displacement is .147 cubic feet. ill figure that in next so chamber one will be a tad wider now sean Gold Member Username: Insearchofbass Post Number: 2651 Registered: Jun-04 Posted on Friday, June 10, 2005 - 05:01 pm: new demesions for chamber one including the subwoofer this time chamber 1...24.7031(45/64) wide by 15.5 high by 23 deep=5.09644395254629 cf chamber 2... 12.6875(11/16) wide by 15.5 high by 23 deep=2.61753110532407 cf |
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Gold Member Username: InsearchofbassPost Number: 2974 Registered: Jun-04 | ok heres how to lay it out these dememnsions i gave you are internal so remember that. when you build the box you want the front ports one over the other evenly spaced there will be four of them on each front chamber. Also make sure when you space them that they are planned so that they arent right up against the top and bottom panel. Then for the interior ports you want them evenly spaced depth wise from your front chamber ports and the back wall of your box internally. So if the ports are 16.5 long and you have 23 inches internal you have 6.5 inches left so you place the ports 3.25 inches from the back of the front ports and 3.25 inches from the back wall. then to figure height you take your 15.5 height and space each port evenly from each other and the top and bottom boards because you dont want the ports touching the top or bottom boards any more than you want your external ports touching the top and bottom boards. I decided it was best to space the internal ports away from each other due to possible vibrations and due to the fact i believe the roundness of the ports will cause a benefit spl wise from the front ports externally and the rest of the volume of the box can be more effectively used behind the internal ports. This is a guess on my part and i also believe the thickness of the ports (3/8) is sufficient for no flexing. As you probably realize you will also have dividers seperating chamber 1 and 2 with holes cut out for each internal port this also will lend the ports inside good support. So if the ports are 16.5 long you split that in half minus the thickness of the divider so 16.5 divided by 2=8.25 minus .75 for wood thickness=7.875 inches of port showing in each chamber. As you can see if you move the ports more side to side other than centered it would change the box volume per chamber so try to stick to centering the ports as i figured them. Also make sure you seal around the ports internally very well this is important as well as the front ports. |
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Gold Member Username: InsearchofbassPost Number: 2975 Registered: Jun-04 | after thought....the divider may not be enough suport alone for the interior ports due to the length of the port so if needed add small support structures for them |
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Gold Member Username: InsearchofbassPost Number: 2976 Registered: Jun-04 | nahh well be ok |
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Gold Member Username: InsearchofbassPost Number: 2977 Registered: Jun-04 | you can do the ports both chambers off to the left |
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Gold Member Username: InsearchofbassPost Number: 2978 Registered: Jun-04 | the external ones i meant of course |
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Gold Member Username: InsearchofbassPost Number: 2979 Registered: Jun-04 | you could also double up the divider wall to two .75 inch pieces and have 1.5 inches of support for the interior ports and have 7.5 inches of port showing in each chamber. This would also give you a sturdy divider but care would just need to be taken to cut both port holes on the boards precise. While also making sure the two pieces were joined tightly. An added effect would be .75 more added to the (external) box width over just a .75 divider originally. |
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 663 Registered: Sep-04 | okay, i follow. thanks a ton. well there one thing i want to just make sure... one sec i;ll draw a picture on paint... |
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 664 Registered: Sep-04 |  |
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Gold Member Username: InsearchofbassPost Number: 2981 Registered: Jun-04 | reverse it |
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Gold Member Username: InsearchofbassPost Number: 2982 Registered: Jun-04 | by the way take a look at my external port post |
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 665 Registered: Sep-04 | okay could i do that?... pretend that the ports are evenly sized and spaced lol... but give the left ports 1 inch distance from the left wall. and 1 inch distance from the right wall to the right ports... 1 inch should be enough? or should i do more? and i;ll figure out how to evenly space the ports and do that. that i can handle lol. and for the sub placement, can i place it all the way to the right of the big chamber? or should it be centered between the mid wall and the left ports? i hope you understand what im saying i probobly get confusing sometimes sorry lol. jus to let you know i was trying to get some space between the left ports and the sub to place an ascendant audio logo... but performance if far superior to that. |
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 666 Registered: Sep-04 | what do you mean reverse it? have the small chamber on the left side? does it matter? |
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Gold Member Username: InsearchofbassPost Number: 2983 Registered: Jun-04 | i know certain what your asking but what i mean is the large chamber goes on the left and the small on the right and the external ports from my ideas would go on the left side of each chamber |
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Gold Member Username: InsearchofbassPost Number: 2984 Registered: Jun-04 | i guess it doesnt matter |
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 668 Registered: Sep-04 | okay give me one second.... i;ll draw to what ur last post says...well what i think. |
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 669 Registered: Sep-04 |  |
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Gold Member Username: InsearchofbassPost Number: 2985 Registered: Jun-04 | as a rule i like to keep the internal ports at least three inches from other ports and walls in all directions |
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Gold Member Username: InsearchofbassPost Number: 2986 Registered: Jun-04 | except in the case of your exterior ports along the side walls you cant give them three inches ....and no that isnt what i meant...ill try to draw |
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 670 Registered: Sep-04 | but yeah, i was thinking it wouldnt matter, and actually if they ports to the small chamber were on the right wouldnt air flow easier through the extermal ports and the internal ports? because...pictures time.. lol.. |
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 671 Registered: Sep-04 | okay i;ll wait for ur drawing lol... but meantime lok at this...   the first one if more desireable right? maybe not... i know they are so far form perspective but....lol |
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Gold Member Username: HdubbFarmington, Nm Usa Post Number: 1911 Registered: Nov-04 | yo trevor check your email man |
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Gold Member Username: InsearchofbassPost Number: 2987 Registered: Jun-04 | i cant draw it no i just meant the 66.666 side on the other side and the 33.333 side on the other side ports left and right |
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Gold Member Username: InsearchofbassPost Number: 2988 Registered: Jun-04 | yes the interior ports go like that |
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Gold Member Username: InsearchofbassPost Number: 2989 Registered: Jun-04 | the first way for the ports is right |
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Gold Member Username: InsearchofbassPost Number: 2990 Registered: Jun-04 | interior ports i meant the first way is right |
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Gold Member Username: InsearchofbassPost Number: 2991 Registered: Jun-04 | part of my comments in my long response to you were visualized wrong as far as the ports increasing the spl |
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Gold Member Username: InsearchofbassPost Number: 2994 Registered: Jun-04 | im gonna get offline here let me know if you cant understand what i meant |
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 672 Registered: Sep-04 | im sorry i had to go get ready, i was suposed to leave an hour ago and im leaving now.. i;ll draw another picture, i think i understand what you mean now though... hunter i;ll get back to about my e-mail thanks a million guys |
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 673 Registered: Sep-04 | hunter... theres nothing in my e-mail???? |
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Silver Member Username: GeekbikePost Number: 213 Registered: Dec-04 | Why so many ports? I haven't modelled it at all, so I can't see how port length works out. With so many ports and how close they are together, it may affect tuning frequency and create some odd resonances. |
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 679 Registered: Sep-04 | umm ask sean. hes the mastermind behind it... lol |
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Gold Member Username: InsearchofbassPost Number: 3002 Registered: Jun-04 | the amount of ports are needed because you have to account for port volocity at the rated power. I modeled it using winisd online version. The reasom i went with 2 inch pvc is because i had to shorten the port lengths because two 4 inch ports would be twice as long and 4 two inch ports would have the same port area as two 4 inch ports. As far as resonances from what ive read so far that usually only comes into play at longer port lengths. Am i right knacko? I know your smart and know your stuff. Ps...of all the abc boxes ive listened to online everyone has port noise and I figured out why...port volocity. In reality trevor should round off each port end to make sure he doesnt have port whistle. |
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Gold Member Username: InsearchofbassPost Number: 3003 Registered: Jun-04 | i tried to stick to the rule of a minimum of three inches from box walls and ports as much as possible but I dont no how to do that for the outside ports with all the other ports. |
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Gold Member Username: InsearchofbassPost Number: 3004 Registered: Jun-04 | you think its tough in the dual chamber knacko think of me with the triple chamber im going to make for my 6.5 inch tangbands. i almost have it all figured out tho on paper but it will require for one inch ports per chamber and 4 inside from chamber 1 to chamber 2 near side and 4 from chamber 2 far side to chamber 3. A total of 20 ports 7 inches long each. |
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Silver Member Username: GeekbikePost Number: 222 Registered: Dec-04 | Port noise has as much to do with velocity as it does with shape and size of the port. Round ports cause lots of port noise because of their shape. The air moves very quickly over the sides and causes the noise. Rounding helps but PVC is limited on how much rounding can be done. Smoothing the flow of air is very important to reduce port noise. Have you thought of using slot ports? Rectangular ports produce much less port noise, are easier to round (3/4" versus 1/8" or so of PVC), gives really good flow and add the the strength of the enclosure. Lengths are longer though.  Something else you could look into is aeroports. |
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Gold Member Username: InsearchofbassPost Number: 3031 Registered: Jun-04 | jonathan actually said the reverse of what you did. He said slot ports have more port noise. Now I wonder which is right? |
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Gold Member Username: InsearchofbassPost Number: 3032 Registered: Jun-04 | the pvc im using is 3/8 by the way areo ports are also a good choice but very expensive in the amount we need and only in certain lengths |
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Silver Member Username: ShadylimitedxPgh, Pa Usa Post Number: 224 Registered: Apr-05 | those abc boxs sound any go0d |
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Gold Member Username: InsearchofbassPost Number: 3033 Registered: Jun-04 | Ill let you be the judge of that http://www.cardomain.com/ride/683513 ABC box 3 ABC box 4 ABC box 5 |
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 688 Registered: Sep-04 | okay i let my mind run and this is what i came up with.... couldnt i have PVC port without port noise... i mean what if i did this....  okay now what if i put resin over the end of the port like that to make a widerpiece for the air to travel past but keep the 2 inch diameter of the port and that would take up very little volume so there shudnt be any difference in perfprmance form that little of a difference in volume... what do you think? also, thats a horible drawing.... i would do it so that it doesnt reallystick out further (port length) but increases the 3/8 width of th e pipe material to like 1 inch. rounded of course. |
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Gold Member Username: InsearchofbassPost Number: 3047 Registered: Jun-04 | just round both edges of your ports and youll be fine less work too. By the way did you see my dual chamber tangband 6.5's abc box is done using that guys specs for them on here (except i used .75 mdf) The box has good output in my living room and is only getting 60 watts rms divided into both speakers off my onkyo home reciever. http://www.cardomain.com/ride/683513 |
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 689 Registered: Sep-04 | congrats sean! next is the 3 chamber right? i cant wait to see what youve discovered.... goodluck with that project im sure its a difficult one. |
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Gold Member Username: InsearchofbassPost Number: 3050 Registered: Jun-04 | i just metered the abc box and hit 104 db in my apartment at 64 hz with 30 watts rms to each 6.5 |
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Gold Member Username: InsearchofbassPost Number: 3051 Registered: Jun-04 | almost 3 feet away i took the measurements and i could have pushed them harder but they arent broke in yet |
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Silver Member Username: Tdeaton1021Near Tampa, Florida USA Post Number: 691 Registered: Sep-04 | nice.,... what do they take? 75w rms each? or 50? or what? lol |
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Gold Member Username: InsearchofbassPost Number: 3052 Registered: Jun-04 | 60 rms each im going to ahve 140 rms amp on the in the car not sure if im gonna add my bass cube to it yet |
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