andym85 Posted September 3, 2009 Report Posted September 3, 2009 the problem compared to mine, is port displacement...because u have to take into account end correction (half the ports width)....so if ur port is 10hx3w...and u want to achieve an length of say 18", really the port only needs to be 16.5" (the other 1.5" comes from end correction).... i will do a few sketches and scenarios later today/tonight when i feel like to try and show u what i mean... i likes me some audio stuff...
Sanitarium Posted September 3, 2009 Report Posted September 3, 2009 Alright, i worked out a formula which matches up with online calculators for square ports but not slot ports. What am i missing? Edit: Figured it out, end correction + made new input box for that. Calculator is done, look for it in my signature soon!
andym85 Posted September 3, 2009 Report Posted September 3, 2009 k...here we go port specs: 4" wide, 10"tall(not shown)....effective length is 21" first up is a "L" port - displacement is .502 next is a slot port - displacement is .522 now i know those two displacements dont vary a whole lot....but it would get more drastic the longer and wider u made it... i likes me some audio stuff...
Sampsonite Posted September 3, 2009 Report Posted September 3, 2009 yes to both tuning is figured after sub and port displacement it kind of becomes a circular equation because of that...if u are any good with excel, then u can figure out a way to account for it...like i did Wheres the dl link for your calculator? --Sampson 816-591-6592 www.kcrimshop.com
Torres Posted September 3, 2009 Report Posted September 3, 2009 I'm majoring in Computer Science, so I'd like to build myself a little program for my own personal use, so knowing the formulas would do me some good there.that's what i'm majoring in as well. i made a box tuning program from visual basic yea, that wouldnt be too bad...that actually wouldnt be too bad at all come to think of it the only thing i dont like about most calcs is that u dont know if port length is the physical length of the wood, or the measurement down the middle of the port....which really is only a problem with "L" shaped ports...because its multiple pieces of wood, but one measurement, and the actuall length of the port that is measured down the middle is going to be quite longer than the wood used to make it... the one i made accounts for that. the 'check if port bends' box changes the physical length of the port so you know how long the actual wood has to be. doing this also changes the net volume just a tad as well, which in turn will change the tuning. it's very minute, but doing this properly makes it all the more accurate. uncheck it, and it's a regular slot port and the 'port length' output box is the same length as the port dimension entered. try zshare.net i know exposport used the same program u did, and that is where he uploaded it... i'm at school so i cant download his, but i clicked the link and his looked like it was made in excel (which i think he said too) and mine was made in visual basic. it's a graphical user interface program so no excel spreadsheet on mine it all sounds simple in theory....but once u sit down with pen and paper, do a few sketches, run thru a few scenarios for hours...u begin to realize making a simple program isnt so simple...and questions will arise that cant be answered... i spent days and days doing sketches and number crunching in college...learned a lot, but also raised more questions for me... yes...yes it is. VERY long and VERY time consuming process. i thought i found all the errors i could find...after it took forever and a day to get all working right...and when i uploaded it over on ***, a user there found an issue right away it seemed. and i completely overlooked it the whole time. it starts to get tricky when you need to figure out where to put certain inputs, where in the coding they need to be in order to execute properly, and how to figure out certain variables and where to put them. like the slot port, or if the port bends or not. it will start out easy. finding the volume of a box - (L * W * H) /1728. then even finding net volume after wood displacement - ((L-1.5) * (W-1.5) * (H-1.5)) /1728. then figuring out port displacement, sub displacement, etc, it just gets all the more fun
andym85 Posted September 3, 2009 Report Posted September 3, 2009 Wheres the dl link for your calculator?nowhere...because i dont feel like explainging it to a ton of people like i have before...lol i likes me some audio stuff...
Maxim Posted September 4, 2009 Author Report Posted September 4, 2009 Wow, reading through these posts just made me understand so much of that I was trying to figure out. I didn't know what "effective length" or end correction was, but now I know that, and I also now know how L-shaped ports work. Makes me feel crazy smart. I'm gonna try to make a spreadsheet of my own so I can better understand this stuff. I'll have it calculate volumes of a couple box shapes and whatnot. I already got part of it in the works, I just need to put the big parts in. Hopefully I'll have it done by tonight. If possible, I'd like you guys to look at it for me so i know I'm doing it right. wtf is lolcats? I'd def get a fat hooker if i had to resort to that kinda thing. I feel like they'd be grateful and work harder. Also its more bang for my buck, more real estate for my dollar if you catch my drift. its like the Costco of streetwalkers. I was hoping for 150 . I was hoping she would let me put it in her butt
Maxim Posted September 4, 2009 Author Report Posted September 4, 2009 Wait, I lied. Confusion is setting in again... End correction is required for a slot port, but not a square port. What is the difference? Does a slot port share at least one wall with the box, while a square port has it's own separate walls? Or by slot and square are we referring to the actual shape of the port? And in sanitarium's spreadsheet, he asks for the number of common walls. What does this mean? The number of walls the port shares with the box? Or is it something else? wtf is lolcats? I'd def get a fat hooker if i had to resort to that kinda thing. I feel like they'd be grateful and work harder. Also its more bang for my buck, more real estate for my dollar if you catch my drift. its like the Costco of streetwalkers. I was hoping for 150 . I was hoping she would let me put it in her butt
andym85 Posted September 4, 2009 Report Posted September 4, 2009 you are correct on both accounts slot port shares at least one common wall with the box...square port does not.. and u r correct on sanitariums spreadsheet from what i gather... trust me..questions will keep coming ..ive been down this road.... but i sincerely applaud u for making the effort of trying to figure shit out so u can know what ur doing..instead of posting the same question everytime somethin arises like some ppl do! i likes me some audio stuff...
Sanitarium Posted September 4, 2009 Report Posted September 4, 2009 Wait, I lied. Confusion is setting in again... End correction is required for a slot port, but not a square port. What is the difference? Does a slot port share at least one wall with the box, while a square port has it's own separate walls? Or by slot and square are we referring to the actual shape of the port? And in sanitarium's spreadsheet, he asks for the number of common walls. What does this mean? The number of walls the port shares with the box? Or is it something else? Yeah, common walls = walls in common with the box. Slot ports can have 1 to 3 common walls. And andy, i've put in a spot for end correction factor with a note on how to use it. Download link is in my Sig, only changes i need to make are either making notes on how to use it or throwing in a seperate document with a diagram.
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