explain different voltages to me plz

Big10Fan

I'm confused, when looking at an amp, do you look at the RMS power at 12.5/14.4/13.8 what is it? How do I know the kinda power my electrical system will supply the amp? I am getting mmc6500 for front and mmc460 for rear I am looking at kicker amps(get deals) and dont want to under or over power. I am assuming It'd be best to get 1 amp for fronts/1 amp for rears and a mono for the sub?

as we all know the mmc6500s are 125w rms and the mmc460 are 50rms


----ALL 4 OHM LOADS---
these are my options if I am going with 2 seperate amps:

kx450.2 on the 6.5's (150.2 @14.4, 90.2 @12.5 plus tack on maybe another 30rms(about) for the amp being underrated)
kx350.2 on the 6.5's (110.2 @14.4, 70.2 @12.5)
SX400.2 on the 6.5's (88.2 @13.8, 100.2 @14.4)
SX500.2 on the 6.5's (113.2 @13.8, 125.2 @14.4)

kx250.2 on 4x6 (85.2 @14.4, 50.2 @12.5)
kx200.2 on 4x6 (70.2 @14.4, 35.2 @12.5)

now if I were to go with a 4 channel amp:

kx650.4 (120.4 @14.4, 70.4 @12.5)
kx850.4 (175.4 @14.4, 90.4 @12.5)
SX700.4 (85.4 @14.4, 82.4 @13.8)
SX900.4 (115.4 @14.4, 107.4 @13.8)

So which would you put on these speakers? also I was wondering, will I notice a difference if I mix a KX with an SX series with sound quality? Sorry to bring kicker questions to a polk forum, but you guys always answer unlike many other fourms, dont let me down :P

AustinKP

Your car battery will usually be around 12.5-12.8 volts, so that is the voltage you'll get when your car is turned off. When it's running, the alternator will put out somewhere between 13-14 volts or so, thus the two different numbers some companies give.
13.8 is an average number you can expect to get from an alternator, so that is probably the most common voltage at which amps are measured.
-Austin

neomagus00

like austin said, if you can get 13.8 numbers, great, if not, i usually go with the 12V ones, for 2 reasons:
1) again, this is the voltage you get with the car turned off, and i listen to music with the car off fairly regularly (usually while washing it )
2) it's generally better to use the smaller number IF the amps aren't known for underrating... if you're looking at polk, mtx, or the like, you'll want the 14.4V numbers because those are likely to be more realistic.

That being said, the sx 900.4 is a good match. i like 4 channels because they're often cheaper than 2 equivalent 2-channels, and it's easier to wire 1 amp, and it gives a more unified look to the car. plus you can biamp much more easily if you decide to try that down the road.

on which series you should get, it depends on the features you want. it is very unlikely you'd hear any sort of sq difference between the two series, so base your decision on the xover flexibility, etc. and looks (it has to look good, too )

Big10Fan

no matter how many I use the prices are really similar, anyway if the 4chan is putting out 100x4 how do you prevent 100wrms going to the tiny 4x6's that only handle 50???

AustinKP

to avoid overpowering the weaker speakers, just turn down the gain.

Big10Fan

I thought gain only as associated with signal from the deck? say I have the gain set 1/3 on the rear speakers of that 4channel amp, how much power do you assume will be going to them?

AustinKP

The gain on the amp is used to match the input signal to what the amp is expecting. For example, my amp's input sensitivity ranges from 0.2V to 6V. At full volume, my HU puts out 4V. Thus, I set the gain on my amp to 4V.

If I had speakers that couldn't handle the power my amp was putting out, I'd set the gain lower, like to 6V so the amp amplified the signal less, giving less power to the weaker speakers. Make sense?
-Austin

Big10Fan

alright that makes total sense now Thanks!

Anyway I have a new question, I drive an 03 silverado extended cab, I want to get in on the group buy for SS, anyways I am not exactly sure how much damp i need, here are measurements

fronts doors 2.5ftx2.5ft
rear doors 1.5 ftx2.5ft
back wall which not much will have room for damping, but its 2ftx5ft, I'd assume maybe 1x5ft will have room after amps are mounted.

thats about 50square feet right?

I just really wanna deaden rattles mostly, does the floor or roof produce rattles? Is it worth the extra effort to try and dampen them(if so whats more worth it floor or roof if had to pick one)? my system isnt the loudest, momo components, some rear fill and a 400w sealed sub 10" downfiring

what I wanna know is how many layers do I install and how(Ive never seen the inside of my door, do you put a piece on every single side of everything? like behind the plastic/on both sides of the part with the holes, and another on the outer skin which would be about 4 pieces)? I want to order today if I get enough replies. is 1 layer enough on most places not near any speakers? I was thinking double up around the speaker area, but as you get 12"+ away from the speaker 1 layer might be fine? you tell me. I'm not a fan of ripping the seats/floor/headliner out to dampen that stuff if It will only cut road noise, like I said mostly rattles bother me. let me know

exalted512

id get 3 gallons of the new spectrum and do the floor and the head liner...
i would call ant, number is listed on www.secondskinaudio.com and see what he says...
-Cody

Big10Fan

Thanks for the reply, but forgot to mention I only want to use mats, I dont want to wait for stuff to dry

swerve

Originally posted by Big10Fan
Thanks for the reply, but forgot to mention I only want to use mats, I dont want to wait for stuff to dry

man you think you are cool.... get your entertainment **** out of the roadshops kicker accomodation book punk.

heh

Big10Fan

Originally posted by swerve
man you think you are cool.... get your entertainment **** out of the roadshops kicker accomodation book punk.

heh

ent is what is keeping CC alive bish :P now u help me l8r when u get on I am ordering tomorrow and I dont want to regret anything

AustinKP

Originally posted by Big10Fan
Thanks for the reply, but forgot to mention I only want to use mats, I dont want to wait for stuff to dry

I used two gallons of the stuff and it only takes like an hour to dry. It's not that bad, but it's HALF the price of the mats. Even Ant, the owner of secondskin will tell you that for the same thickness, the liquid is better than the mat. Anyway, it's your decision, but I thought I'd let you know my experience.
-Austin

Big10Fan

It's hard for me to believe an hour to completely dry enough to put the interior back in? I'm doing the install at a friends house, so go morning and have my truck back together by night and out of there... I'm still thinking I'm just going to try the doors first, and hopefully down the road if I need to do other parts, maybe he'll have another discount.

neomagus00

i dunno, austin did put an awful lot of the stuff on - go here, scroll down, find texas, look at the pix. i'd trust his word on this one.

Big10Fan

after replying I went to SS forums, everything I've read has been let it dry an hour between coats, then 24hours before putting interior back in.

neomagus00

you can't deal with no panels for 24 hours?

Big10Fan

no =(

situation:
new truck (03 silverado) parents dont like the idea of upgrading anything in it, the only reason I got my alpine h/u in was cause I had to say it was sat radio, and I had to say it only cost $200(more like 550 after adapters) if I leave my truck at a friends house(which i never do) there will be too much to explain to them, they will wonder why its there, then i'd have to say why, then in the process of that I'd have to say I have speakers/amps comming in the mail. It's too much of a mess to deal with, I'm actually having everything I can sent to friends house so they wont notice, then just on weekends do stuff little by little. haha sux right?

Big10Fan

Ok, now on to wiring, I checked out the manuals for the 4001. and the 900.4 the 900.4 says 2awg and the 400.1 says 4awg....1/0 kits can get expensive... length from battery to amps is about 12-13 feet (including making corners) what kind of wire do I have to run? how would I do it? whats the difference between a battery terminal and a distro block? I'm assuming the wiring rule goes as follows, 1/0 can split into 2 4awgs and a 4awg can split into 2 8's?

swerve

Originally posted by AustinKP
I used two gallons of the stuff and it only takes like an hour to dry. It's not that bad, but it's HALF the price of the mats. Even Ant, the owner of secondskin will tell you that for the same thickness, the liquid is better than the mat. Anyway, it's your decision, but I thought I'd let you know my experience.
-Austin

austin, that is V2 right? I'm going to V3 everything I think being the rich mother F***** that I am nowadays.

ahahah

-adam

neomagus00

a battery terminal is a piece that you stick on the battery to make it easier to run audio and stock cables off the battery. you'll want the 2 gauge cable - larger isn't necessary for your application. a distro block takes that 2 gauge power line and splits it into multiple power lines, one for each amp. an identical block is used to collect the ground cables into one large cable. the wiring rule isn't as simple as you've guessed - it depends upon length, too. so that 2 gauge could be split into 2 2-gauge wires, if you wanted. those amps can take 4 and 2, and i'm sure a distro block can be found that takes in a 2 and makes a 2 and 4, and that will work well.

swerve

Originally posted by neomagus00
a battery terminal is a piece that you stick on the battery to make it easier to run audio and stock cables off the battery. you'll want the 2 gauge cable - larger isn't necessary for your application. a distro block takes that 2 gauge power line and splits it into multiple power lines, one for each amp. an identical block is used to collect the ground cables into one large cable. the wiring rule isn't as simple as you've guessed - it depends upon length, too. so that 2 gauge could be split into 2 2-gauge wires, if you wanted. those amps can take 4 and 2, and i'm sure a distro block can be found that takes in a 2 and makes a 2 and 4, and that will work well.

but neo... can you just have 2 grounds as well?

neomagus00

you can indeed. but:

grounding to two different places is just asking for ground loop noise. thus, you always ground everything to the same bolt, and if everything's going to the same place anyways, may as well simplify it and get a d-block, which will make for a cleaner install with less cable. and can make expansion much easier.

swerve

Originally posted by neomagus00
you can indeed. but:

grounding to two different places is just asking for ground loop noise. thus, you always ground everything to the same bolt, and if everything's going to the same place anyways, may as well simplify it and get a d-block, which will make for a cleaner install with less cable. and can make expansion much easier.

guess i'll hav4e to pick a ground distro up...