im gonna build a box for 4 8" subs pretty soon( gonna go with memphis subs again) sealed box... going for sound quality over loudness...
should i seal off each sub? run 2 subs per enclosure? one big enclosure?
i would think seperate enclosures would be the way to go..
the box is gonna go across the back wall keeping it under the window level.
im hoping to run a memphis 500/1 mclass amp for the subs and either the 200.4 mclass amp my boss has or go with the 300.4

 

which model memphis usb are you going to use

tang-band has an awsome 8 if you wanted some other options

 

id be going sealed for each one.. but listen to kyle hes got good input^^

 

i'd also go seperate boxes for each sub. if anything were to happen to one of them... you could disconnect it, and continue to use your system... if they're all in one box, that one sub not working would throw off the other subs.

 

HUH? if the one wasnt working oh well.. who cares..doesnt change much..i found that with one big open area and 4 subs there always fighting against 1 and another pushing air..put 2 subs in a non enclosed box turn 1 on and watch how much teh second one unplugged moves and then hook them both up and listen to teh difference i used to have a box like that then went to ported with a single chamber each WAY CLEANER WAY NICER!

 

tang-band? is that the brand?
with the memphis subs, i was going to go with the M class.. i had 4 12s memphis PR's in my last truck and they were louder than crap! and my buddies truck, he had 2 10" of the mclass, and were crisp!

 

8'' subs.... why even buy subs?

 

it changes everything. when you build a box and have multiple subs using common space, the box must be built with the appropriate cubic volume for the sum of the subs. simple example- you have 2 subs.. each requires about 1 foot of cubic volume for a sealed enclosure. putting them both into a box where they'll share box volume, the box volume itself is 2 cubic feet while both subs are in it, firing away.. if one sub were to cut out... that would leave just one sub, but now with a box volume of 2 cubic feet instead of 1, and that will not sound right.

that's not exactly whats happening... but, at the same time, i prefer seperate spaces for each sub anyway, so... i'm fine with that.

i really don't know what this means. you just compared a ported chamber to a sealed box... totally different worlds.

 

^^^[/QUOTE]it changes everything. when you build a box and have multiple subs using common space, the box must be built with the appropriate cubic volume for the sum of the subs. simple example- you have 2 subs.. each requires about 1 foot of cubic volume for a sealed enclosure. putting them both into a box where they'll share box volume, the box volume itself is 2 cubic feet while both subs are in it, firing away.. if one sub were to cut out... that would leave just one sub, but now with a box volume of 2 cubic feet instead of 1, and that will not sound right.


....makes sense

 

why does everyone figure it says REC 1 cubic foot it only can have 1 cubic foot?im runnin 8.25 cubic feet for subs that only rec 3 for both total? and its killer loud and killer clean? you just get a deeper bass..


and duh..THEY STILL FIGHT against eachother..you tell me how they dont.. go take your 1 chamber box turn on both subs now unplug one and watch the one thats not plugged in it still moves when the others going and when there both on there fighting eachother...i dont see how you figure there not? the box will not be as loud as a sealed chamber for each sub..ive made lots of boxes and built many systems and nothing has sounds as nice as sealed chambered box..

im not here to argue but put my point of view out there..i dont have one of the loudest rangers /systems kicken around for no reason..just look at my cardomain.

 

thanks! i was planning on building the box this weekend but i think im gonna stay inside and keep warm! im not used to it being 30-40degrees haha.
the subs im thinkin bout havs 100rms 200 peak.. i think a 500w amp would be just right... or would yal think it would be too much stress on the amp powering 4 subs...
and a concern i have... im runnin a 4ch amp now... and when i add the 500w amp, will it be ok to run 8ga to each amp without the wires getting to hot? i think splitting the 4ga into 2 8ga should be sufficient

 

my .02 cents
sealed enclosure for each
if you have all in one enclosure and one busts... if you really think about it the presure that the othere subs make as they push in are actualy pushing the busted one out (making an oposite sound wave) canceling out some bass.. not smart
and as the good ones push out the busted one returns to normal (making an oposite sound wave(.. again))canceling out some of the bass... again

sorry
physics rules!

 

depends on the type of box you are going to build. i never use what the manufactures put on their boxes as recommendations. i use the t/s parameters, just like anyone else that knows what they're doing would do.

you're probably well aware, but i'll post it anyways... the proper equation for a sealed box volume is as stated.... Vas / (((Qtc / Qts)^2)-1). using an optimal Qtc of .707, you can go ahead, punch in your t/s parameters, and be on your merry way. the formula to calculate box size for the coupled design is exactly the same, except that the Vas is entered as twice the stated spec of one driver.

go ahead and find your t/s parameters, and try it out... you'll see that the box for two sharing a sealed chamber is nearly double that of a single driver.. which is what i've been saying all along.

yes they still fight each other, that is because a properly sealed box is just that- sealed!!!! in a well sealed, coupled box, you push in on one sub, you will see the other push out... this is because you are moving the air within. when one is powered, yes it will push the other, looking like it is still playing, even though it may not be plugged in.


after reading and trying to understand what you're getting at, i'm coming to the conclusion that one of us is misreading the other's posts, lol.

 

here is a pic of one of their 8's, uses neo mag: 120rms 12mm xmax



150rms for this one^

they arnt the prettiest things but they are nice

you feeling naughty go for this 8...

 

thats a 8............HELL i want 2 lol

 

 

eh... this isnt necessarily true.

sealed boxes, if built properly, have less distortion and coloration across the entire sub frequency range than a comparable ported setup. ported boxes exhibit less distortion mainly at and around the ported frequency only.

when youre dealing with a sealed enclosure, and you're sharing airspace between multiple subs, thats not automatically bad. in fact, it would sound pretty much exactly the same as the same sealed box where each sub had its own chamber. theorhetically, if you have say, 2 subs, and each sub requires 1 cubic foot of airspace for a sealed box, and you built a sealed box for both subs with 2 cubic feet of total airspace, as far as the subs are concerned, they each think theyre in a 1cuft box.

the problem lies in that if one sub dies, then the other sub suddenly has all that airspace to itself, which is obviously more than it should have, and audio quality will suffer.

 

Exactly what i was saying.

plus.... if you've got two subs sharing airspace in a single box, you will actually gain up to a 6 dB increase in SPL at any given amplifier volume if wired in parallel, and up to a 3 dB increase if wired in series... depending on the characterisitics of the amplifier.

 

Another thing to consider if that if you are using a monoblock amplifier, or a bridged connection (ie common single) you are SUPPOSED to use common airspace. Why? Because contrary to your idea of subs "fighting" each other, this allows them to work together. If you use a mono amp and push 2 subs side by side, but in separate sealed enclosures it is possible that they may fire slightly off from one another. If that occurs, you can suffer fro cancellation and sloppy sounding bass.

On the contrary, when you take those same two subs and put them in common airspace they will be sharing the push and pull of the air, which will keep them much closer together in their movement.

You should never run multiple subs off the same signal in separate enclosures.

 

ding ding ding!

 

well dam! i just got confused haha.
i talked to some guy today at a stereo shop and he suggested 2 L7 8's in ported box with a kicker 1500.1 amp... would that setup work?
i just know im gonna go with 8s or 1 10... but cant decide

 

hey man... it's been a couple of weeks now... did you ever decide on what you were going with?

 

probally going to do 1 10" sub just to keep it simple and clean install. i want my interior to look simple and clean.
i just quit my job b/c of some bullsh1t and im gonna put a drop on my truck in 2 weeks.. but once my friend buys my door speakers im gonna run the factory ones off my amp and choose a 10" sub and amp and hide everything