rockFord_Expedition Posted February 17, 2015 Author Report Share Posted February 17, 2015 this is a great question.. bl, fs.. ... ported vs sealed... great question... Yeah, getting really tired of being in that group of people that thinks what are the ideal enclosure specs for this sub or that one etc then relying on a box guru (or not) to come up with a design and then just trust it, or thinking ok I have a certain amount of space, what subs/power/enclosure will work best etc. I want to learn and be able to apply that knowledge. Old School/New School RF Build March 2015 SOTM Winner How to crimp large wire Link to comment Share on other sites More sharing options...
rockFord_Expedition Posted February 17, 2015 Author Report Share Posted February 17, 2015 BAM https://docs.google.com/file/d/0B_l73GVBBlIUNTc2YTc2YTktNTNmYi00YWNmLTlmY2ItZTU0MTRhMzdkYTAy/edit?pli=1 Edit: Although what Mustang posted best helps figure out what enclosure to start with. I am still interested in what if any T/S parameters determine how much volume will be required. Like let's say 2 speakers have entirely identical T/S specs, except 1 parameter. Could that 1 make one speaker over the other require more, or less air space? And the same for port area. I remember seeing something about how bl and xmax are directly related to the amount of air space required. Just never fully looked into that. Exactly, and thank you Old School/New School RF Build March 2015 SOTM Winner How to crimp large wire Link to comment Share on other sites More sharing options...
kirill007 Posted February 17, 2015 Report Share Posted February 17, 2015 Loudspeaker design cookbook by Vance Dickason. And modeling is the only way to really know. Obviously to know for what type of enclosure it likes, you just calculate the EPB (Fs/Qes) anything over 100 is for ported enclosures, anything under 40 is for sealed enclosures.(and anything in between, you can choose) You take the Qes and divid it into the Fs of a driver. Depending on the number you get will show what enclosure is ideal for that individual speaker. 0-50, Sealed is highly preferred. 50-100, The speaker will work well in both ported and sealed. If it's 100+, then it is highly preferred to use a ported enclosure. Credit to user RooTxBeeR Lol, double post Thinking is the root of all problems... You ALWAYS get what you pay for. Link to comment Share on other sites More sharing options...
rockFord_Expedition Posted February 18, 2015 Author Report Share Posted February 18, 2015 Original post edited, question reworded. There has been some good input thus far, keep it coming. Old School/New School RF Build March 2015 SOTM Winner How to crimp large wire Link to comment Share on other sites More sharing options...
rockFord_Expedition Posted February 20, 2015 Author Report Share Posted February 20, 2015 TTT for more info Old School/New School RF Build March 2015 SOTM Winner How to crimp large wire Link to comment Share on other sites More sharing options...
aculous Posted February 20, 2015 Report Share Posted February 20, 2015 look at Basic Car Audio Electronics. There is a calculator that based on T/S parameters tells you whether a driver would be better for ported or sealed enclosures. Beyond that you are going to have to test the enclosure type in winisd or some other modeling software. And even that has its limitations. Although WinISD gets you pretty close. You just have to play with it. Link to comment Share on other sites More sharing options...
rockFord_Expedition Posted February 20, 2015 Author Report Share Posted February 20, 2015 look at Basic Car Audio Electronics. There is a calculator that based on T/S parameters tells you whether a driver would be better for ported or sealed enclosures. Beyond that you are going to have to test the enclosure type in winisd or some other modeling software. And even that has its limitations. Although WinISD gets you pretty close. You just have to play with it. But how do you do it in reverse? Like in math you learn that 3 x 4 = 12, then eventually you learn that how to solve for x in the equation 3x = 12 Well traditionally we say ok I have this much electrical and a certain quantity of a particular sub, now I need to find an enclosure to suit this situation (yes there is more to it like vehicle type etc but bare with me) and this is where WinISD is like the equation 3 x 4 = ____ where 3 is kinda like our electrical and 4 represents our subs and ____ is our enclosure. I am trying to solve for x, where if I know the given electrical potential and enclosure space and desired tuning, how do I pick subs? Old School/New School RF Build March 2015 SOTM Winner How to crimp large wire Link to comment Share on other sites More sharing options...
aculous Posted February 20, 2015 Report Share Posted February 20, 2015 I wrote up a super long response and then hit the back button like an idiot. You can't go in reverse, you did it wrong from the beginning it seems like so most likely you will have to start over. And traditionally I have NO idea why you would go electrical>sub>enclosure. Almost all SPL subs are going to be made for ported enclosures...4th/6th/transmission line. There I just saved you a bunch of time and you don't have to look at basic car audio electronics like was mentioned above. So heres the short version. -Before you buy anything....driver or amp or electrical....MODEL THE SUB. -You HAVE to have T/S Parameters in my experience. If you don't have them, Dayton Audio has the DATS system or you could use a SMD IMG-SG to obtain them or a mic could do it too (read above book) -Once you have the t/s parameters you can model it in WinISD but you have to have some idea of where you are going 4th order/6th/IB/Tranmission Line and that takes research -When you model one and get the freq response and performance you want plug info into torres, that will give you a cut sheet -buy a measurement mic and use REW to make sure things came out as planned or modeled Tweak as needed. Check out decware for their deathbox plans or whatever. The enclosure is crap for the most part but the design is cool because you can mess with tunning frequencies however this is only going to be for a bandpass design. Link to comment Share on other sites More sharing options...
rockFord_Expedition Posted February 20, 2015 Author Report Share Posted February 20, 2015 Thank you for chiming in. This isn't what I have done so to speak, or how i recommend going about things, but just trying to think in a little different manner than traditional and see if we can use this "reverse" method to see what T/S parameters would be needed from a sub. Old School/New School RF Build March 2015 SOTM Winner How to crimp large wire Link to comment Share on other sites More sharing options...
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