air space and fiberglass

89fivept0

i've gotten pretty good with working with fiberglass with the compleation of my front end that was hit on my mustang. so i decided to make a custom box out of fiberglass. i just dont know how much air space, and if i should add ports. and if i do add ports, then where do i put them so they will sound the best. this is going in the back of my durango. the subs that i have are 2 12inch polk momos.. i donk know which ones though, im too lazy to take them out of they box and look. whats the difference between the MM2124DVC and the MM2124... and whats the best amp to push these two? i had a SPL 1600, but i blew that some how. my next choice is the kicker 1200.1... thank -Jeremy

neomagus00

the difference between those two subs is that one has two voice coils, and can handle twice the power (i THINK, someone else confirm/deny!).

on sealed vs. ported: it's all personal. ported can be louder, but sealed usually sounds better, and takes up less space. for a ported box, you want the ports to open into the listening area, which usually means having a hole of some sort through the rear deck (which is often then covered with a speaker grille to look stock).

the best amp depends upon which subs you have and how much you want to spend.

exalted512

if youre going to do ported i would consider making it out of all mdf and not fiberglass. reason being its a lot easier to tell the volume of a pure mdf box than a fiberglass one. with ported boxes, just a little off in the volume can tweak the sound.
you can always make the box, then fiberglass on top of the mdf to match the curves of the interior. as far as how you should place the subs/ports. i would do subs up, ports facing the rear...just because its louder:D
-Cody

silva95teg

he is correct the sub has 2 voice coils , but it does not handle twice the power , i think both versions handle 400 watts rms , 2 voice coild just gives you a little more flexabitity in wiring , thats all. as in one sub can have two 4 ohm voice coils so you can wire it in parallel to 2 ohms , so if you had an amp that put out 400 watts rms at 2 ohms it would match it.

MacLeod

As far as I know, the DVC subs handle twice the power. Jesus, at least I hope that right. Ive been telling people that for months. We're about to start getting a lot of complaints of shredded DVC Momos!!

KIM!!!! Get in here!!

Actually I just used the search feature and found this.

I new I was right. Never doubted it.

silva95teg

well i have talked to quite a few people , and all of them have said they handle the same power , also if you look at the specs for both those subs it does not list the dvc to be twice that of the svc , i think what you mean is that a dvc sub will draw twice the power from an equiped amp , one that is stable at that impedance , but i might as well be wrong , i am assuming the power per coil is half that of the svc sub

silva95teg

after reading this i am pretty sure they do not handle twice the power http://www.jlaudio.com/tutorials/dvc/index.html

MacLeod

Well, according to Kim, who knows these things, they handle the rated power PER COIL. So that would be 300 for the MM2104 and 600 for the MM2104DVC.

As you read, Kim stated just that in that thread about the MM2084DVC. Plus Ive been telling people for months that the DVC subs handle twice the SVC ratings and if I were steering people wrong surely one of the moderators wouldve stepped up and corrected me.

Kim? Josh? A little clarification please.

neomagus00

silva - note that the link you posted, while informative (i've read all of jl's tutorials previously), IS written by JL. Innovation happens all the time here, so it is certainly possible that the polk DVCs can handle twice the power that the SVCs can.

That, and Kim said so in the link Mac posted.

silva95teg

well you are right innovation comes around and maybe polk dvc's do handle twice the power of the svc'c i would just assume that polk would make use of those figures and rate their speakers that way. if someonecould clear things up it would be much appreciated

silva95teg

well it could also be that kim is completely right and each coil can handle 200 watts rms , but maybe when both coils are connecten in series or parallel the power handling does not go up , only the effective resistance changes , hey i am only throwing some ideas out there , someone will clarify thing i am sure

MacLeod

Ya dont understand. Kim is the customer service mack daddy. Its his job to know everything about Polk gear and he does. If he says it, you can bet on it.

Hopefully one of the mods will see this in the morning and clear it all up. My reputation is at stake.

silva95teg

well , i dont know about kim and i am sure working there he does know his stuff but i have my manual in front of me right now and both the svc and dvc subs have the exaxt same posted ratings , like i said before, if polk made their woofers special i am sure they would most likely exploit that fact. my 2 cents , i am not meaning to cause any heated debates or anything

89fivept0

i was asking what the difference was between the mm2124 and the mm2124DCV. i dont know where the SVC's came up i compared the specs and there is very little difference that i could tell. i might be wrong. as for my other questions.... o well


i pretty much got them all answerd, the air space was given to me in the polk manual, im going with a 2200 watt audiobahn. i have a friend that im going to paint his body kit for his car, and in return he's giving me a good deal on that amp and is going to help me build that box. he works at audio plus so i trust him. i dont know if thats the best amp, but he's selling it to me for 100 bucks so im going to take it. so now all i need are some highs and an amp for them and i'll be set. as for the rest of the car im just going to hit up my grandfather and see if he'll buy me some 22's. after all he said i was his favorite grandson so im putting it to the test. i cant wait to start the fabrication, i'll post pics as i go

neomagus00

wait, you're actually considering putting 22s on a mustang? isn't that illegal, somehow?

oh, and svc describes the vast majority of subs that are not dvc, the mm2124 included.

89fivept0

Originally posted by neomagus00
wait, you're actually considering putting 22s on a mustang? isn't that illegal, somehow?

oh, and svc describes the vast majority of subs that are not dvc, the mm2124 included.

no i have a mustang now, putting 22 on durango

MacLeod

Ick. Youre not gonna like that dude.

The Durango is a truck built on a truck frame and as such aint the smoothest riding vehicle in the world cause its made to be hauling big loads. You put 22's on there and thats gonna be a lot of hard, unforgiving metal between your suspension and the road. Stick to 16's and get bigger tires. Much better ride.

And yeah, Audiobahn blows but for $100 why not.

silva95teg

if he has a brand new durango it will be fine they have a more car like suspension

MacLeod

Actually Im just against the whole 48" wheel thing. Especially on cars.

First it was those stupid go cart wheels that stuck out 16" on each side and bent tie rods. Now its the 52" wheels on a 83 Monte Carlo that had to be raised to fit. These trends just get more and more stupid looking. Or maybe Im just too old.

neomagus00

apparently i am too, then. i'd never put anything bigger than 17s on my car, cause it'd look retarded, and those 17s better be damn nice lookin (this counts, even though the page loads wrong)
18s look bad on all but the biggest cars and some suvs. bigger than that is simply wrong (i think the 22s on suvs are funny, cause then the brakes look like children's toys )

silva95teg

that is why with wheels like that you always upgrade to a big brake kit ...

exalted512

im thinking about 17x10 welds on the new truck...
im going up from 16s:D
-Cody

neomagus00

Originally posted by silva95teg
that is why with wheels like that you always upgrade to a big brake kit ...

ah, but most people don't. sure, it can look good on the right car with the right wheels in the right setup, but most people aren't that... well, right...

silva95teg

i agree with you on that one most people dont , and there are lots of vehicles that look like **** with them too , but even the new dodge trucks come with factory 20's if you want em