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Silver Member Username: Langless28Post Number: 132 Registered: Dec-04 | how do i calculate dimensions for a ported box tuned to like 30hz i hear that good for sq and spl am i right? the sub is a polk mm2124 |
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Silver Member Username: Algirard1OH United States Post Number: 109 Registered: Dec-04 | Go to http://www.accelerator-pedal.com/l-ported-box.htm |
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Silver Member Username: Langless28Post Number: 133 Registered: Dec-04 | how would you tune a sealed box to that fq? is it possible cus im really cramped for space and ive been listen to ported enclosures my whole life so im worried i wont like sealed. |
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Gold Member Username: InsearchofbassPost Number: 1801 Registered: Jun-04 | looking up your sub as we speak to design you a box |
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Gold Member Username: InsearchofbassPost Number: 1802 Registered: Jun-04 | what is the usable demensions of trunk space you have for a box? |
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Silver Member Username: Langless28Post Number: 134 Registered: Dec-04 | well its for a jeep cheorkee and im using that panel with a indent in it and i want the box to be as stealth as possible |
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Gold Member Username: InsearchofbassPost Number: 1803 Registered: Jun-04 | what kind of power are you running to it? if you could go measure that area in the jeep it would help alot ...make sure you give yourself room for error |
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Silver Member Username: Langless28Post Number: 135 Registered: Dec-04 | umm its round 190 rms and this is what im kinda leaing towards http://www.cardomain.com/memberpage/791202/5 but space wize im just not sure to go sealed or ported. i have it in a ported box now and its sounds real good but i never head a sealed box all my old subs were in ported. |
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Gold Member Username: InsearchofbassPost Number: 1804 Registered: Jun-04 | ok i got an idea now lemme punch a few more numbers |
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Gold Member Username: InsearchofbassPost Number: 1805 Registered: Jun-04 | ill tell you now ported is you best option for that sub when i run it in my box program |
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Silver Member Username: Langless28Post Number: 136 Registered: Dec-04 | alright on their site they give 1.5 cuft and a port of 4 inch diameter and 10 inches long. i think that is like 40hz tuned i think but i want to go down to like 30 or 35 |
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Silver Member Username: Langless28Post Number: 137 Registered: Dec-04 | also what box program do you have? is it free |
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Gold Member Username: InsearchofbassPost Number: 1806 Registered: Jun-04 | no it isnt free its probox professional....are you going to build exactly like this guy did on that link? or not? |
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Silver Member Username: Langless28Post Number: 138 Registered: Dec-04 | well of couase im gonna make so it looks pleasing to me and im not sure if i want to use the panel as the back with glass, i still thing it wont be as ridgid |
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Gold Member Username: InsearchofbassPost Number: 1807 Registered: Jun-04 | i have an idea if you are |
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Silver Member Username: Langless28Post Number: 139 Registered: Dec-04 | sure |
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Gold Member Username: InsearchofbassPost Number: 1808 Registered: Jun-04 | i meant are you definately going to use that location |
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Silver Member Username: Langless28Post Number: 140 Registered: Dec-04 | yeah i want to |
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Gold Member Username: InsearchofbassPost Number: 1809 Registered: Jun-04 | if you definately want to use that location ported looks out of the question for sq do sealed and line it with say an .75 to an inch of poly batting that comes in sheets...if it boost your box to 1.40 cf sealed your center frequency will be 50 hz and your cuttof will be 43.37 hz youll have alot of drop off after 50 hz but you jeeps cabin gain should even that out ...should be a very nice sq box |
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Gold Member Username: InsearchofbassPost Number: 1810 Registered: Jun-04 | well as nice as you can get with that space |
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Gold Member Username: InsearchofbassPost Number: 1811 Registered: Jun-04 | the more space the better....optimum is 2.65 cf sealed |
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Silver Member Username: Langless28Post Number: 141 Registered: Dec-04 | why is ported outa the question cus if u look at that pic their is alot of unused space over the tire well. i wanted to cut the port at an angle so it comes outa the box near the seat and goes throught the box over the wheel well (all inside the box of course) |
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Silver Member Username: Langless28Post Number: 142 Registered: Dec-04 | then why does the polk site say a sealed box of .88 is ideal? |
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Silver Member Username: Langless28Post Number: 143 Registered: Dec-04 | what im most afraid of is how diff ported and sealed boxes sound? i listen mostly to rock then thiers the ocasional thechno song to show off my system and a little bit of hip hop |
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Gold Member Username: InsearchofbassPost Number: 1812 Registered: Jun-04 | i dont no but i can tell you in that size it will sound like crap trust me....if you want to do ported here was my idea build your enclosure and use the 4 inch portidea you had and cut the hole out like you need to of course then take as long of a length short of 3 inches from the back of the box and run test tones and listen to it or run music and cut some off a little at a time until you hear what you want it to sound like...you may need extra pvc tubing till you find what you like with the test piece |
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Gold Member Username: InsearchofbassPost Number: 1813 Registered: Jun-04 | try the ported and make and adaptor plate like i did if you want to go sealed or ported whenever you want |
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Silver Member Username: Langless28Post Number: 144 Registered: Dec-04 | well at 1.5 cubic feet what size port would i need for a tune of 30-35hz? and im rusty on math how do you find cross section area of say a 4 inch dia port so i can start using that long a$$ equation. |
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Gold Member Username: InsearchofbassPost Number: 1814 Registered: Jun-04 | to make an adaptor plate simply cut out a square window and make an internal bracing for the plate to screw into and cut out your 4 inch pvc hole in one and mount it and make a plate solid without any holes to place over the cutout to make it sealed when you want to go sealed...thats what i did....its flush mounted too |
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Silver Member Username: Langless28Post Number: 146 Registered: Dec-04 | and with your program requardless of using that space or not, what is the ideal box/port combo for that sub? |
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Gold Member Username: InsearchofbassPost Number: 1815 Registered: Jun-04 | just use this http://www.linearteam.dk/default.aspx?pageid=ventcalculator |
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Silver Member Username: Langless28Post Number: 147 Registered: Dec-04 | thanks alot what is the acoustic power? |
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Gold Member Username: InsearchofbassPost Number: 1816 Registered: Jun-04 | if it was me id do a 2.00 cf box and drop the sub in and port it to 33 hz but youll prob have a little port whistle at that tune |
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Gold Member Username: InsearchofbassPost Number: 1817 Registered: Jun-04 | that would be 1.85 cf after dropping the sub in if the subs displacement is .15 cf its the rms power...(basically the true rated power) |
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Silver Member Username: Langless28Post Number: 148 Registered: Dec-04 | yeah dont want any port whistle how do i find acoustic power? |
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Gold Member Username: InsearchofbassPost Number: 1818 Registered: Jun-04 | its the rms power of your amplifier ...what amp is it? |
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Silver Member Username: Langless28Post Number: 149 Registered: Dec-04 | i appreaciate all the help sean. ill do my best i really want to lean towards ported so i guess i fool around with the design for a while. my sub is in a ported box now 1.5 cf 4dia port 10 inches long and it sounds good. this new box plan is for a rainy day or for the summer time to keep my hands busy. so i have some time to tinker. if i were to build a .88cf sealed box with 3/4 foam on the inside with polyfil, how do you think that would sound compared to the box it is in now(my ported box has polyfil in it as well) |
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Silver Member Username: Langless28Post Number: 150 Registered: Dec-04 | alpine mrd-m301 at 4 ohm i know thier stuff is underrated |
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Gold Member Username: InsearchofbassPost Number: 1819 Registered: Jun-04 | ahh very good...your at about 1.90 cf with the poly if its a pound and with the new info i found ...trust me on this it goes against what they were teaching....your at about 1.90 cf after displacements for the sub which brings you to a 37 hz port tune... i bet you pound all the way through the 50hz to 60 hz spread dont you...and you prob barely have any port whistle if at all ...duplicate that box again af far as airspace and port size and length and the same amount of poly |
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Gold Member Username: InsearchofbassPost Number: 1820 Registered: Jun-04 | well if your running 175 rms at 4 ohm your fine |
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Silver Member Username: Langless28Post Number: 151 Registered: Dec-04 | alright thanks, as for i should have no port whisle i would be able to detect it right, like its not something minute right? also since nobody on speakers thread talks. i have the polk momo mmc5250 comps and i was wonderin if i were to put plactic and tape on the back of the speaker and then put glass resin on it, then took off the plastic and tape leaving a removable fiberglass cone. would that be a good idea for an enclosure for the speaker? or is this a stupid idea? this is my last ? for now so thanks for all your help. laters |
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Gold Member Username: InsearchofbassPost Number: 1821 Registered: Jun-04 | you would here it yes it would be a low pitched whistle in your case if you have any at all |
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Gold Member Username: InsearchofbassPost Number: 1822 Registered: Jun-04 | as far as your other question youd have to ask jon or glass about that im not familiar with that area |
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Anonymous | hey could someone tell me what all the colored dimensions on that site are? and also what is the drivers displacement.... ex: qts, vas, etc. and does the net volume include the mdf and sub or are u suposed to subtract that from it before u enter the net volume? thanks alot |
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Gold Member Username: InsearchofbassPost Number: 1824 Registered: Jun-04 | not sure what your asking concerning the colored demensions...the displacement is the amount of space taken up by the subwoofer and your ports if you have any...your ports are almost nill space wise but anyway the qts vas etc is your theil small specs for the sub it usually comes written on a sheet in the box with the sub if it has any referance but if not you call the manufacture to find out these specs but your best approach would be to ask for a box size and type to what your goals are like sq or spl or a mix of both and tell them your rms power of your amp and it will make things easier for you....thn simply build to the specs the give you |
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Anonymous | hey thanks a ton sean but im sorry im an idiot... the colered dimentsions is what they give u and they are color coded for better understanding... thanks |
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Gold Member Username: InsearchofbassPost Number: 1825 Registered: Jun-04 | yw |