Cubic Ft w/ a backward sub?

[Epic18s]

Suppose I wanna do a setup kinda like this with out the subwoofer in the box just the one facing into the box(to try to save room in my truck between the seats). Will I need the same recommended cubic ft for the subwoofer or will it be greater or smaller. Thank you

[mnchvgs79]

It will be slightly smaller, but only smaller the amount of space you are saving by not having the speaker inside the box... make sense?

Remember if you do it that way, you need to reverse speaker polarity.

If you set it up just like is shown in the picture (isobaric) you can cut your box volume in half but it takes 2x the drivers to make the same SPL

[shady4evr]

dont have a clue but i want to know. i like the idea a bunch. i might glass them and make some cool box for it. who knows.

[bigroy80]

you will actually need a smaller box because now you extra air that the sub is not taking up anymore

[shady4evr]

so you need to overdrive the crap out of it to make it sound the same as if it were in the box the way it was meant to be?

am i correct in that statement

[mnchvgs79]

so you need to overdrive the crap out of it to make it sound the same as if it were in the box the way it was meant to be?

am i correct in that statement

No, power requirments stay the same. The box volume is the same, minus the space in the box ie. box needs to be slightly smaller. The speaker magnet and cone and frame take up a bit of space when mounted "normally" in a box, you just have to subtract that from the box volume.

[shady4evr]

you will actually need a smaller box because now you extra air that the sub is not taking up anymore


ok now i am lost. i need to sit down with one of you guys. probably scott and talk to him about this. cuz i might glass some speakers into a custom box/console. who knows. the possiblities are endless with an extended cab.

[shady4evr]

im lost i will have to sit down with yall before i go and build a custom box.


dan that is your duty for me when i get back building my box. that will be a pain in my arse. plus it will get you away from the wifey. lmao.

[bigroy80]

just read adams its a lot more explanatory. by the time i finished typing my post there was already 2 new posts before i could finish haha

[02sonoma]

i cant glass for shiot man... if anything i'll show up to laugh at you for trying...haha

lets say you fill a tub to the top... then you get in, the water goes over the side right? all your doing when you turn your subs upside down is... subtracting the space the subwoofer takes up in the box, and getting rid of that measurment in your dimensions... so instead of a rightside up cone needing 1.25 cf... it only needs 1.00 upside down... (just an example, probably way off) get it dave?

[mnchvgs79]

i cant glass for shiot man... if anything i'll show up to laugh at you for trying...haha

lets say you fill a tub to the top... then you get in, the water goes over the side right? all your doing when you turn your subs upside down is... subtracting the space the subwoofer takes up in the box, and getting rid of that measurment in your dimensions... so instead of a rightside up cone needing 1.25 cf... it only needs 1.00 upside down... (just an example, probably way off) get it dave?
Good explaination

[shady4evr]

i cant glass for shiot man... if anything i'll show up to laugh at you for trying...haha

lets say you fill a tub to the top... then you get in, the water goes over the side right? all your doing when you turn your subs upside down is... subtracting the space the subwoofer takes up in the box, and getting rid of that measurment in your dimensions... so instead of a rightside up cone needing 1.25 cf... it only needs 1.00 upside down... (just an example, probably way off) get it dave?


now i feel like a total idiot. lmao that was a great explanation. FROM NOW ON ADAM WILL DO THE TECHNICAL SIDE OF EVERY ? THAT COMES THROUGH HERE AND DAN WILL EXPLAIN IT IN DUMMY TERMS SO THE REST OF US CAN UNDERSTAND. lmao.

thanks i understand now.
but how do you calculate for how much airspace you have when you build a box?

[mnchvgs79]

LxWxH/1728

[Epic18s]

I will have to reverse polarity? could you please explain this in detail. Thank you

[mnchvgs79]

I will have to reverse polarity? could you please explain this in detail. Thank you

The speaker has to function backward since it is mounted upside down. meaning you have to run + to - and - to +

[shady4evr]

so pretty much after all of that you just have to find out how much each speaker is allotted for airspace. and then reverse the polarities on them and that is it. no biggie now. pretty simple. thanks

[Epic18s]

What would happen if it was wired the regular way?

[mnchvgs79]

What would happen if it was wired the regular way?
blown subs worse case

sound ****ty for sure

[nickf829]

alot of distortion when regular polarity.. my subs are inverted like that, and i am running only 1 cu ft per sub and its badass IMO i've had people complain they aren't "that loud" but honestly i think its badass for what i want... i show up a few people but i like the quality moreso then the crazybass

[Epic18s]

mnchvgs79, I understand what your saying but I'm just curiouse how they could blow since they would be wired originally how they're supposed to be.(If that made any sense)

[mnchvgs79]

mnchvgs79, I understand what your saying but I'm just curiouse how they could blow since they would be wired originally how they're supposed to be.(If that made any sense)
because you are doing something that isnt normal, the speakers are not meant to be run that way, therfore you need to correct for that by inverting the wiring. Personally I wouldnt run speakers like that, you lose so much cone area by inverting them. Inverting your speakers will essentially take a 12" woofer and make it put out the sound of a 10"

[Epic18s]

Looks like I'll just have to build a regular box then.

[dloonam]

I just got done putting mine in inverted and still trying to finish it up. Instead of reversing polarity if the amp has a phase control I heard you can run it 180 degrees out of phase and do the same thing. Is this true or am I working on blowing my sub too? It sounds pretty good now I was just wondering....

[mnchvgs79]

I just got done putting mine in inverted and still trying to finish it up. Instead of reversing polarity if the amp has a phase control I heard you can run it 180 degrees out of phase and do the same thing. Is this true or am I working on blowing my sub too? It sounds pretty good now I was just wondering....
The phase 180 switch will do the exact same thing. You will be all set

[dloonam]

The phase 180 switch will do the exact same thing. You will be all set
Aight, cool. I just wanted to make sure, I really like this sub and I'm not looking to blow it already...

[El Camino SS]

thats my old sub u cheap bastard u better not blow it