Box rise

[THATpurpleKUSH 5,000+ posts]

This article explains impedance rise pretty well:

The Rise to Power

 

[Popwarhomie 5,000+ posts]

Oh you mean the miniature midgets you look at lol

//content.invisioncic.com/y282845/emoticons/yumyum.gif.0556df42231b304b9c995aefd13928a8.gif

 

[kr15 5,000+ posts]

I hate to generalize, but you can often get rise down by decreasing volume and increasing port area... im also of the camp that believes it matters 0 in daily builds.

Competition on the otherhand.... was at a show on Saturday in which someone made 2000w in the 5k class. That isnt ideal

 

[youdoofus]

Impedance rise won't damage the subs. Heat will.

i know that, its not my subs that ever suffered any ill effects, it was my amp

 

[youdoofus]

This article explains impedance rise pretty well:
The Rise to Power

the info in that article is pretty much how i understood box rise before posting, good read tho. Suffice it to say that im still not putting that sq2200 back in my car until i get some 0 gauge welding wire, its just the funds situation that has prevented me from doing it yet and on top of that, my dog got bit by a husky at the dog park the other day, so off to the vet we go today and the impending bill for said services will put another hold on the project

 

[Papermaker85 5,000+ posts]

Sealed boxes/enclosures have no box rise.....I think, correct me if I'm wrong.
I mistakenly wired a MTX 81000D amp to 2 15w3 subs to 1 ohm and didn't even hiccup, or get warm.

Wrong

 

[Kam311]

the info in that article is pretty much how i understood box rise before posting, good read tho. Suffice it to say that im still not putting that sq2200 back in my car until i get some 0 gauge welding wire, its just the funds situation that has prevented me from doing it yet and on top of that, my dog got bit by a husky at the dog park the other day, so off to the vet we go today and the impending bill for said services will put another hold on the project

What wire were you running before?

 

[hispls 5,000+ posts]

If you are attempting to play more than 1 frequency ever this whole subject should not even be considered, if you are doing 1 frequency burps the only use of knowing your impedance at peak is knowing how low you can drop nominal impedance safely.

Making your box less efficient for the sake of saying you "get more power out of my amp" is really pissing into the wind IMO.

 

[youdoofus]

What wire were you running before?

still running the memphis ofc 4 gauge. its connected currently to a ppi pc250 to one sub, so its sufficient for its current use, but ive learned over the last year+ that it was woefullt insufficient for 200 amperes of draw over 15ish feet. I saw some charts that say that its sufficient for 200 amps of draw for a couple feet tho (i think, id have to find that chart again and double check) Pi$$er of the deal is that the amp died shortly after completing the big 3 with the 4 gauge i had from the original install that i was just unable to get to for a long time due to laziness and injuries

 

[youdoofus]

If you are attempting to play more than 1 frequency ever this whole subject should not even be considered, if you are doing 1 frequency burps the only use of knowing your impedance at peak is knowing how low you can drop nominal impedance safely.
Making your box less efficient for the sake of saying you "get more power out of my amp" is really pissing into the wind IMO.

ok, wasnt sure about that on the box rise topic. What about prolonged bass notes like what is found in many edm tracks? Thanks for your input, its always appreciated //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif i like the idea of a sealed box for a better overall response, but am thinking of going ported with a mild port for the sake of efficiency, and i guess i dont know what you mean about cutting efficiency for the sake of "getting more power from my amp"

 

[Kam311]

still running the memphis ofc 4 gauge. its connected currently to a ppi pc250 to one sub, so its sufficient for its current use, but ive learned over the last year+ that it was woefullt insufficient for 200 amperes of draw over 15ish feet. I saw some charts that say that its sufficient for 200 amps of draw for a couple feet tho (i think, id have to find that chart again and double check) Pi$$er of the deal is that the amp died shortly after completing the big 3 with the 4 gauge i had from the original install that i was just unable to get to for a long time due to laziness and injuries

Haha wow, yeah 4awg for a 2k amp, that's asking for smoke for sure. You were like "why do these amps have such huge terminals?! “

 

[youdoofus]

Ha!! Yeah, I had the gain at 1/3 at most so I thought I'd be ok. Guess not lol

 

[Kam311]

ok, wasnt sure about that on the box rise topic. What about prolonged bass notes like what is found in many edm tracks? Thanks for your input, its always appreciated //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif i like the idea of a sealed box for a better overall response, but am thinking of going ported with a mild port for the sake of efficiency, and i guess i dont know what you mean about cutting efficiency for the sake of "getting more power from my amp"

What is a mild port?

Ha!! Yeah, I had the gain at 1/3 at most so I thought I'd be ok. Guess not lol

Well I hope that by now you've learned that having the "gain up 1/3 of the way" means nothing. That could be full power depending on the voltage being sent by your head unit.

 

[youdoofus]

What is a mild port?


Well I hope that by now you've learned that having the "gain up 1/3 of the way" means nothing. That could be full power depending on the voltage being sent by your head unit.

i dont want a box to be the entire size of my trunk, but would like to keep both 12"s, so a smaller port as id rather still be able to access the spare, call me paranoid. Yeah, i have indeed learned that the amperage requires it to have sufficient cabling

 

[Kam311]

i dont want a box to be the entire size of my trunk, but would like to keep both 12"s, so a smaller port as id rather still be able to access the spare, call me paranoid. Yeah, i have indeed learned that the amperage requires it to have sufficient cabling

Not only that but your head unit is putting out a certain voltage, and setting your gain is matching that voltage. So depending on the voltage your head unit is producing, 1/4 gain might be full power, or full gain.

Now as for fitting two 12's in a trunk Ported, you aren't going to do it without it taking up most of your trunk. You need a certain amount of Port area or you risk annoying port noise and compression issues. So just doing a small port isn't really an option unless you go with a bigger box. Small port and small box don't really go together, which is why designing a good box is often challenging when limited in space.

Most 12's Ported need about 4 cubes. And judging by the size of the 4ft box in my truck, good luck lol. Go check out the box I posted in the build log section for two tens in my brothers focus, that's only 2 cubes. Two tens are very practical for people worried about getting to their spares while still having a Ported box that bangs.