posted
i have finished creating a hybrid sub consisting of various parts including a cone, surround and spider from a dd9515, but with a 4" former and different magnet and frame. i believe i have created my own weapon of mass distruction as it was designed for extreme power applications and is very stiff, so much so i could stand on it! but unfortunatly its also probably the worlds most inefficiant sub as it moves about 10mm with 5000wrms!! but that aside'
i want to know if theres a formula or some way i can work out the correct magnet vent size? it must be small enough to have back pressure that will be forced down beside the former and windings and out of the vents in the side of the basket but be big enough not to cause any undue restriction the the cones motion! do i work out the volume of air space between the underside of the dustcap and the pole piece and use the vent sort of like a port? or is there a way to work out how much resistance a certain sized vent will have on the cone? or perhaps a way to work out what percentage of air would go to each vent! back and the sides ih and the reason i ask this after its been built is that it normally has a vent that is way to big and i have to work out what sized restrictor to put in the hole.
anyone care to tackle this one
-------------------- _ _____________ _ *on 2004 rules - *australian extreme 1 record holder!* *Owner and builder of australia's loudest extreme spl car* 1 Digital Designs 9915 + 4 concept d2400a's -"160.9" on new termpro meter Posts: 37 | From: western australia, | Registered: Jul 2002
| IP: Logged |
quote: is there a way to work out how much resistance a certain sized vent will have on the cone? or perhaps a way to work out what percentage of air would go to each vent
yes. ask a university physics professor.
BTW designing drivers,without any backround info will be extremely difficult.
Its cool that u are DIYing it though...but u have to know alot! That sort of info you wont find on the net even,or youl find boring thesis and PDF Files at .edu sites and not be sure how to apply it to ur problem.
what id do- measure the t/s specs and see what they are!
posted
i could measure as many as posible manually,i do have a program that does t/s paremeter measure ment but my computer isn't set up for it
but seeing as its spl only' specs like those are not really needed, mabe Fs though! but i can tell you its extremely low, this sub plays subsonics i kid you not! i put it in my car just for a laugh and put 700wrms behind it(there was no cone movement at all!) and the only sound was 10 meters away where stuff was falling of shelves but no bass in the car .
building subs from scratch is easy! building one that sounds good with music and inproves upon a factory design is harder there must be some physics guys here?
-------------------- _ _____________ _ *on 2004 rules - *australian extreme 1 record holder!* *Owner and builder of australia's loudest extreme spl car* 1 Digital Designs 9915 + 4 concept d2400a's -"160.9" on new termpro meter Posts: 37 | From: western australia, | Registered: Jul 2002
| IP: Logged |
posted
put in a adjustible one like infinity uses then adjust accordingly
-------------------- 2001 dodge ram reg cab with sport package pioneer premier hu pioneer (2) 2inch mids and (2) super tweeters kicker IQ900 EQ crystal 5's in fiberglass kickpanels (2)crossfire 404's 4ch 400 watts each mmats dhc 1400.2 1400 watts mmats d300hc modded 0 watts(needs new board) (4)interfire 12's in 3.6 cu. ft. sealed box(daily driver)153.8 on AC 1 15 inch stroker in 5.5 cu. ft. (spl)needs reconed 1 15 inch armageddon sealed for (SQ)very tight and accurate sub Posts: 161 | From: huntington wv | Registered: Jun 2004
| IP: Logged |
![[Razz]](tongue.gif)
![[Frown]](frown.gif)
![[Smile]](smile.gif)
![[Confused]](confused.gif)
![[Eek!]](eek.gif)
![[Big Grin]](biggrin.gif)
Printer-friendly view of this topic