Ported or sealed?
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 64 Registered: Jan-08 | as most people probably know by now i plan to get a Fi Q 12. i know they are a SQ sub, which is what i want, but my question is now, should i go with a sealed box or a ported box? i know ported increases power handling and makes the sub louder. but would a ported box diminish the SQ of the sub, and if it will, will it be by a lot or wont hurt SQ much at all? as i've stated before, i do play some rap but mostly rock. should i stick with a sealed box or would i be ok with a ported? a local dealer will sell me a 1.5 ft^3 for $80. that would give me 1.34 ft^3 after sub displacement. would that be right for a Fi Q? |
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Gold Member Username: CtmikeCt. Post Number: 5830 Registered: Feb-06 | who said ported increases power handling? and i would go ported tuned low if you have the room. |
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Gold Member Username: Nd4spd18Northwest PA Post Number: 6078 Registered: Jul-06 | You need the box custom built for the sub. A low tuned ported box can sound as good as a sealed |
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Gold Member Username: •cam•BC Canada Post Number: 1900 Registered: Nov-06 | And don't forget that there aren't just ported and sealed enclosures. |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 66 Registered: Jan-08 | being able to make a ported box that would still sound as good as a sealed would be ideal for me. how do i make a ported box though? i've made one before but only by following an already pre-designed box. what is the math involved in knowing how large the volume of the box is and how long and wide to make the port? can anyone give me detailed instructions or know a great site?? |
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Silver Member Username: Stateprop486PA Post Number: 312 Registered: Jan-08 | http://www.subwoofertools.com/forum/ported-box.asp |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 69 Registered: Jan-08 | great site, but its giving me some weird looking box saying it's 200 and some inches deep. i keyed everything in right i believe. the max height i have counting wood is 15.5" and max depth is 2 foot. width is up to around 40" or so. can anyone help? |
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Silver Member Username: JnoelAIM= j69noel, KY Post Number: 978 Registered: May-07 | ported if you got the room......that's just my preference though....and please dont go prefab |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 70 Registered: Jan-08 | what's the formula's for box size, port length and port width? and i was thinking last night...the sub needs to be in a box from 1.8-2.5 ft^3. thats huge. if i made a 2 ft^3 box that would have to be 20 inches deep, 14 inches tall and then 38 inches wide in internal size. |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 72 Registered: Jan-08 | ok i downloaded WinISD and put in all the info on my sub. the box it told me is going to be 28.1 inches wide, 12.1 inches deep and 15.5 inches tall. it will be a total of 2.271 ft^3 with a port size of 14 inches tall and 1 inch wide. total length of port will be 21 inches. the tuned Hz will be 24.80. does this sound right? |
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Gold Member Username: InsearchofbassPost Number: 7883 Registered: Jun-04 | dont do a port more than a 8 to 1 ratio |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 75 Registered: Jan-08 | ok so if i did a 14 inch tall, by 2 inches wide, that would work correct? i would just need to have the length of the port changed accordngly. i've never used winISD before, i think i understand it. i'd just hate to make a box by following plans that weren't right. |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 76 Registered: Jan-08 | i'm not understanding this... according to the WinISD program, to have my port length not be some huge length, longer than my box is, the port needs to be short and then 2 inches wide. the wider i go in port width, the longer the number. but i can't go one inch because then its more than a 9 to 1 or 8 to 1 ratio. so my ideal size is only like 13 inches tall, if that, by 2 inches wide. i've never seen a slotted port that short though. normally the port will be the height of the box, minus the wood making the box, and then however long it needs to be. i cant make my slot 14 inches tall though because at 2 inches wide the port need to be 47 inces long. how is this going to work?? |
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Gold Member Username: InsearchofbassPost Number: 7884 Registered: Jun-04 | a 14 x 2 will probably give you port noise at between 1000 to 1200 rms and a very long port |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 77 Registered: Jan-08 | Finally. ok i think i got it now. the box is going to be 15.5 tall, 11 deep and 29 across. port height will be 14 tall and 2 wide. 1 to 7 ratio, should be good right? tuned at 30 Hz. port length is 31.5 inces long. my question now is, does it matter where the subwoofer is placed along the baffle? should it be dead center, far right, far left, or does it matter where it is placed at?? |
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Gold Member Username: InsearchofbassPost Number: 7885 Registered: Jun-04 | well this is where you have to create a port that is made with turns to make it fit in the box and the turns will cut down the length because of a thing called end correction basicly you take the width of the port and cut it in half and for every turn thats how much length is taken off the total length |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 78 Registered: Jan-08 | ok so since there is one turn and my port width is 2", the total length will be 30 1/2" now. is 30 Hz low enough? i tried to compute 28 Hz but the port and length was too large. i'm going to draw up a sketch of the box today at work and post it to make sure everything looks right. i want this box to be perfect :o) |
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Gold Member Username: InsearchofbassPost Number: 7886 Registered: Jun-04 | place the subwoofer on the far side away from the ports internal start but a few inches from the box wall |
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Gold Member Username: InsearchofbassPost Number: 7887 Registered: Jun-04 | 30 hz is fine you wont play any music that will go lower than that and yes you are correct on the port length...the ports going to take up room so adjust for that but im sure you know that |
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Gold Member Username: InsearchofbassPost Number: 7888 Registered: Jun-04 | it might have some port noise at 1200 watts rms |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 79 Registered: Jan-08 | i dont believe winISD takes into consideration of sub. displacement. so i made a box of 2.41 ft^3 - .16 for disp. = 2.25 ft^3 of room. tuned to 28 Hz so it works now. is 28 Hz better than 30 Hz, is there a big difference? |
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Gold Member Username: InsearchofbassPost Number: 7889 Registered: Jun-04 | honestly id stick with a 30 hz test tone...like I said you wont play any music that goes lower than that....and your right linearteam doesnt account for subwoofer displacement...It looks like youve done your homework before posting on ecoustics...just remember to calculate how much room the port takes up too...if you havent already |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 80 Registered: Jan-08 | ok so here is the ported box enclosure i drew up for my Fi Q. i just have a couple more questions and i should be good to go with this box. 1.) when measuring cubic feet of the box, do you just measure the area where to the sub is, the "main" part of the box, or do you also take into consideration the area that the port has?? in the drawing i just got the volume of the area where the sub is, not counting the port itself at all. 2.) my sub should be mounted on the right side of the box? so it is right in front of the port opening? i was thinking of mounting to it dead center. i know that most are more to the right side though. 3.) do the dimensions on this drawing look correct? as far as making it 30 Hz, if you think I should do that i can just shorten the length of the port and it will drop it down to 30 Hz. oh and bracing. i'm guessing i should brace a box of this size. my question is how many braces, and where should i place them? i was thinking of doing 2 pieces of mdf using them like pillars, one of each side of the sub, as proportional as possible. good idea or no?  |
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Gold Member Username: Mike11202DD9515G VFL 200.1 = : , Sewell, NJ US Post Number: 1283 Registered: Nov-06 | Ehh just get someone to professional design and build it for you. I would HIGHLY Recommend JD Builder. VERY Cheap and outstanding products. Tell him Mike, with the SS and JL sent you. http://eastcoastenclosures.homestead.com/index.html |
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Gold Member Username: InsearchofbassPost Number: 7936 Registered: Jun-04 | "1.) when measuring cubic feet of the box, do you just measure the area where to the sub is, the "main" part of the box, or do you also take into consideration the area that the port has?? in the drawing i just got the volume of the area where the sub is, not counting the port itself at all." Right you only count the usable area the subwoofer is in minus the subwoofers displacement not the port too but you made a mistake you fogot to include the area after the port 13.5 wide roughly by 2.75 deep by 14 high 519.75 equals .30 more in usable internal volume...also I looked on fi's website for the fi 12 q and the displacemnt for the sub is .12 no big deal though so we have 2.19 cubic feet net plus the .30 thats 2.49 cubic feet net but your port length is wrong using a 2 x 14 for a 28 hz port tune you would need a 33.25 port length but with end correction it would be 32.25 but with 26.5 inch long port which your drawaing looks like its showing plus end correction youll have a 30.36 hz port tune 2.) my sub should be mounted on the right side of the box? so it is right in front of the port opening? i was thinking of mounting to it dead center. i know that most are more to the right side though. mounting it to the center will be fine 3.) do the dimensions on this drawing look correct? after my corrections like I said youll have 2.49 cubic feet net |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 87 Registered: Jan-08 | man thanks a whole lot for the help. i will shrink the box down a little, cause i want to stay around 2.15 ft^3 total since thats the mid-range of the recommended specs. for me to achieve a 30 Hz port it should be the physical length of 36.5 inches? |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 88 Registered: Jan-08 | man thanks a whole lot for the help. i will shrink the box down a little, cause i want to stay around 2.15 ft^3 total since thats the mid-range of the recommended specs. for me to achieve a 30 Hz port it should be the physical length of 26.5 inches? will that port length stay relivant even if i change the size of the usuable area by shrinking the box down? |
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Gold Member Username: InsearchofbassPost Number: 7937 Registered: Jun-04 | you can add bracing if you like but it will take up room inside the box as long as you dont use too much it wont change things much in that reguard but putting bracing in the corners where the sub gets its airspace will be good (the four corners.. im not talking inside the port ) that should be good enough |
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Gold Member Username: InsearchofbassPost Number: 7938 Registered: Jun-04 | if you change the size of the usable area for the sub the port tune will change if you give it less the port tune goes up with the same port size if you give it more the port tune goes down with the same port size |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 89 Registered: Jan-08 | the port length now in the drawing is 28 5/8". the total area, counting all space is 2.45 ft^3. i am going to shrink the box by one inch of the depth and on the width. doing that, counting sub disp. will give me the 2.15 ft^3 i was looking for. the height, 14 inches, will remain the same. when i do this, how long will the physical port length need to be to achieve 30 Hz? (sorry for bugging so much, i just want to make sure everything is correct) |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 90 Registered: Jan-08 | my head hurts... ok so i keyed in the sizes into WinISD and for the measurements i gave it, with 2.31 ft^3 for 2.15 after sub disp. it gave me a port length of 29.7" for 30 Hz. taking in consideration on end correction, this is 28.7 which is roughly 28 11/16". is this correct? with the following adjustments to size as stated above ^^? |
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Gold Member Username: InsearchofbassPost Number: 7951 Registered: Jun-04 | if you keep it at 2.15 cubes after the sub and port youll need 33.75 inches with end correction 32.75 for a 30 hz port tune... but looking at your port original length in the diagram it doesnt look like you have 28.5 inches of port length even with end correction can you tell me you port length measurements I cant see them right oh by the way I forgot to give you the link to this port calculator before http://www.carstereo.com/help/Articles.cfm?id=31 |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 92 Registered: Jan-08 | if u look, there is a faint line, dead center from the beginning of the port to the end of the port. measuring from the opening to the center at the turn is 12.75" and from the corner there to the end of the port is 15 7/8" equaling 28 5/8" port length. am i measuring from the wrong area? if so where do u start measuring from? |
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Bronze Member Username: 2000celicaRoanoke, VA U.s. Post Number: 93 Registered: Jan-08 | that calculator page is awesome! says i need 33.63 length for 30 Hz. 32.63 after end correction. thanks a whole lot man. |
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