Head unit so many choices

thumpin07

Whats the best way to determine the amp needed for the sub Look at the rms rating for each and get as close as possible, And look at the ohm's too, i dont know ive never done this before its all new and exciting. Also i plan on running three mono blocks one for each sub , i realiaze having 4 amps will require alot of power how do i take care of this problem.

thumpin07

your telling me to run 125w rms into the momo components they are only rated for 100wrms and peak at 200 rms is 125rms really safe to do with out blowing them

thumpin07

im curious like half my thread dissaperd

thumpin07

I i have decided on the subwoofers i want and need some advice, i was thinking either three 12 inch Alpine type r series, or two type r 12 inch and one type are 15 inch, all dvc 2+2 ohm. which would be better three 12's or 2 and a 15?

Also what are good amps to power these subs and to power the Polk/momo components up front?

I am also wondering if i will need to fool with capacitors, and extra battery and junk.i want to pretty much keep it simple, But i want to shake the earth with bass but at the same time have the music loud clear and distinct.

thumpin07

If anyone could help i would greatly appreciate it

MacLeod

thumpin07 wrote: »

Whats the best way to determine the amp needed for the sub Look at the rms rating for each and get as close as possible, And look at the ohm's too.

Yes. Get an amp that will make as much power as your sub is rated for RMS. As for ohms, it depends on how many subs youll be running. If youre running a single DVC sub - get an amp stable to 2 ohms mono. A pair of DVC subs, get an amp stable to 1 ohm mono and so on.

your telling me to run 125w rms into the momo components they are only rated for 100wrms and peak at 200 rms is 125rms really safe to do with out blowing them

They will be fine. 120 watt speaker wont blow at 121 watts and your 125 watt amp isnt putting out 125 watts all the time. So long as you dont build up more heat in the voice coil than it can dissipate, the speakers will be fine. Just use common sense with the volume and gain and if you hear the speakers bottoming out - pull back.

I i have decided on the subwoofers i want and need some advice, i was thinking either three 12 inch Alpine type r series, or two type r 12 inch and one type are 15 inch, all dvc 2+2 ohm. which would be better three 12's or 2 and a 15?

Dont mix subs. Doesnt work. If youre going to use 12's, use 12's. Since youre just wanting to be insanely loud, get three 15's.

Also what are good amps to power these subs and to power the Polk/momo components up front?

The new PA amps from Polk would work just fine.

I am also wondering if i will need to fool with capacitors

No!

and extra battery and junk

Double NO! You do need a good battery and a good alternator.

i want to shake the earth with bass but at the same time have the music loud clear and distinct.

thumpin07

MacLeod wrote: »

Yes. Get an amp that will make as much power as your sub is rated for RMS. As for ohms, it depends on how many subs youll be running. If youre running a single DVC sub - get an amp stable to 2 ohms mono. A pair of DVC subs, get an amp stable to 1 ohm mono and so on.



They will be fine. 120 watt speaker wont blow at 121 watts and your 125 watt amp isnt putting out 125 watts all the time. So long as you dont build up more heat in the voice coil than it can dissipate, the speakers will be fine. Just use common sense with the volume and gain and if you hear the speakers bottoming out - pull back.




Dont mix subs. Doesnt work. If youre going to use 12's, use 12's. Since youre just wanting to be insanely loud, get three 15's.



The new PA amps from Polk would work just fine.



No!



Double NO! You do need a good battery and a good alternator.

why you shaking you head mac is that not possible to do lol I was thinking of running one mono block per sub to eliminate the problem of droping the ohms to low is this a good idea? or should i go with one big amp and run the three subs off of the one amp?
The subs im getting are rated at 500 rms for the 12's or if i go with the 15's they are 600 rms

black magic

That headshake made me laugh.

The number of amps you'll need depends on the power output of the amp. For example, if you have two 4 ohm 500watt DVC subs, an amplifier that puts out 1000 watts @ 1 ohm would be perfect. If the subs are SVC, then you'll want to find an amp that puts out 1000 watts @ 2 ohms. This should help you decide:
http://www.crutchfield.com/S-pnFcYB12Q5s/learningcenter/car/subwoofers_wiring.html

thumpin07

ok that kinda of helped, the subs will be three alpine type r 12 inch dvc 2+2 ohm
they are rated at 500w rms what would be a good amp to power these im going to run three amplifiers due to the extreme low impedence of these subs if i wire them together they wil be below 1 ohm, so im going to run three one ohm amps any ideas on a good amp

thumpin07

i am corrected if i wire them together they will be a three ohm load, but is it possible to run each sub at a 1 ohm load? im still confused but the lower the ohms the better right? or am i mistaken?

thumpin07

the subs will add up to 1500 rms and according to crutchfield's diagram they will be a 3 ohm load, 1 0hm per sub= 3 ohm load on the amp. So would a amp that makes 2,000 watts rms be safe to run? or should it be less than 2,000 watts rms?

thumpin07

crutchfield also stated that the diagram they should was not for a low impedence system to to the rarity of amps that will handle ohms that low. how would you wire three 12 inch dvc 2+2ohm subs at a low impedence, and do they even make amps that will handle a load that low?

black magic

I think low impedance usually refers to anything below 2 ohms. Some amplifiers such as Zapco and the new Polk amps can handle down to 1 ohm. There's a number of other amps that handle low impedances as well.

If you wire the three dvc subs in series/parallel, you'll have a 3 ohm load
http://www.crutchfield.com/learningcenter/car/subwoofers_wiring.html?imageID=3DVC%5F2%2Dohm%5Fmono

I don't think most amps will have a power rating printed for 3 ohms, but you can have a rough estimate by calculating average between the power output at 2 ohms and 4 ohms.

So for example, if an amp puts out 500 watts @ 4 ohms and 1000 watts @ 2 ohms, I would estimate that it'll put out 750 watts @ 3 ohms. This is probably different in reality, but I think it'll give you a proper estimate. I'm not 100% sure about this, so you might want someone to verify it.

It'll be hard to find an amp that puts out 1500 watts at a 3 ohm load. If it was me, I'd get those subs with dual 4 ohm voice coils (if available) and get 3 amps that put out 500 watts at 2 ohms like the Polk C500.1. If you can only get those subs with 2 ohm voice coils and you want to use 3 amps, you'll have to find amps that put out 500 watts at 4 ohms or 500 watts at 1 ohm.

thumpin07

This stuff is really tricky how much head room should i allow for the amps and subs? I do not want to blow subs, or fry amps. Mac told me it is better to give the speakers a little extra power, than to not give them enough power. Also crutchfield reccomended putting in a capacitor and a extra battery to run 4 amplifiers, Mac said there was no need to fool with that, what do you think black magic?

thumpin07

I think for the subs im going to run three Polk PA 600.1 amps they put out 600 watts rms at 1 ohm so plenty of power. and for the polk/momos id like to go with a polk amp but not sure which one would work best for me any ideas?

thumpin07

it might be more work but would it be better to go with a 4 channel amp and biamp the compnents up front, how is this done, and please help me find a amp for the components

thumpin07

i am not a genius at this stuff so anyhelp is appreciated

Deadof_knight

Pioneer Ib and Bt models are nice with 4 volt preout blutooth ipod control usb connections

thumpin07

ive allready decided on a head unit thanks im looking for a amp to power the polk momo components in the front

black magic

thumpin07 wrote: »

This stuff is really tricky how much head room should i allow for the amps and subs? I do not want to blow subs, or fry amps. Mac told me it is better to give the speakers a little extra power, than to not give them enough power. Also crutchfield reccomended putting in a capacitor and a extra battery to run 4 amplifiers, Mac said there was no need to fool with that, what do you think black magic?

Well, I'm still a car audio noob and I'm not at all an expert, but I would take Mac's advice and just upgrade the battery and alternator, then I think you'll be fine. I had purchased a cap for my setup but I sold it because I heard they can cause electrical problems. Plus, I believe a cap is used to make up for a voltage drop - its better to fix the problem than to find a temporary fix which is kind of like what a cap does. An additional battery will add more strain on your alternator (in most cases). I'm still using my stock alternator and battery and I'm using 3 amplifiers which generate 1400 watts and I haven't run into any problems... but then again, I don't really crank up the volume. As for your second concern, most people will agree that you should buy as much power as you can afford, as long as you know your limits... in other words be careful with your gain and volume knobs.

thumpin07 wrote: »

I think for the subs im going to run three Polk PA 600.1 amps they put out 600 watts rms at 1 ohm so plenty of power. and for the polk/momos id like to go with a polk amp but not sure which one would work best for me any ideas?

Sounds like a good plan, even the PA400.1 would be a decent choice. Right now, I'm using a Polk C400.4 to power my MMC6500 components and it provides plenty of power. If you want one of the new amps to match with your sub amps, both the PA200.4 and PA500.4 would probably work, but I'd go for the PA500.4 or C400.4 if you can dish out the extra cash.

thumpin07

well i might need a battery upgrade, but my alternator is still strong and good. Might replace the battery with a optima battery. also does anyone know where the best place to mount my crossovers would be I really want to keep them out of the doors and mount them somewhere else, crutchfield shows them installed in the door itself, but polk recommends against it. So where would a good place to mount them be I was thinking in the trunk near my amps; since stuff has a habit of getting my floor in the cab wet like accidently cracked windows, or the kids spilling something.

I know i will need a distribution block to run the power for the 4 amps, what gage wire should i use coming off the battery to the block, and from the block to the amps? Also where would a good place to mount these amps be, there is a wall in my trunk that would be perfect but it will have the sub box against it, due to space issues and the size of the amps i dont think i will be able to have them neatly in a row. might have to put one hear, one there wherever one will fit lol. i dotn know if it would hurt the amps but i was thinking one amp on the shelf where my spare tire goes, i have room next to it for one amp and possibly the crossovers, the other three might fit on the wall behind the bumper i dont know about this location since they will be hidden from view and also the subs would be fireing directly at them. i will post a pic of my trunk soon from a few angles so you all can get an idea of what i have to work with.

thumpin07

Also thought of another question how do i run the rca cables to the amps, i will have three monoblock sub amps and either a 2 or 4 channel amp for the components. so my question is on the back of the hu there is only one preout for the sub do i run one sub amp off of this preout and then go from amp to amp to amp with the rca's or do i run a seperate rcas from the hu to each individual amp, just curious how this works and hwo do u use a 4 channel amp to bi amp the components?

thumpin07

any ideas guys

thumpin07

if anyone can help me please

black magic

thumpin07 wrote: »

well i might need a battery upgrade, but my alternator is still strong and good. Might replace the battery with a optima battery. also does anyone know where the best place to mount my crossovers would be I really want to keep them out of the doors and mount them somewhere else, crutchfield shows them installed in the door itself, but polk recommends against it. So where would a good place to mount them be I was thinking in the trunk near my amps; since stuff has a habit of getting my floor in the cab wet like accidently cracked windows, or the kids spilling something.

I know i will need a distribution block to run the power for the 4 amps, what gage wire should i use coming off the battery to the block, and from the block to the amps? Also where would a good place to mount these amps be, there is a wall in my trunk that would be perfect but it will have the sub box against it, due to space issues and the size of the amps i dont think i will be able to have them neatly in a row. might have to put one hear, one there wherever one will fit lol. i dotn know if it would hurt the amps but i was thinking one amp on the shelf where my spare tire goes, i have room next to it for one amp and possibly the crossovers, the other three might fit on the wall behind the bumper i dont know about this location since they will be hidden from view and also the subs would be fireing directly at them. i will post a pic of my trunk soon from a few angles so you all can get an idea of what i have to work with.

Its not a question of whether or not your alternator is in good condition, its how much power it can output. For example, my stock alternator is only like 75 amps, but I purchased one which puts out 175 amps. a high output alternator will generate more power and charge your battery faster. I find that the best way to find ideas on how to install your setup is to go to as many auto/audio shows as you can. You can also look at galleries online like cardomain.com. You can put the crossovers next to your amps (thats what I did) or if you're running an active setup you don't even need them. Some people even put their crossovers in their glove box, but i think thats a little ghetto.

As for your wiring, most headunits will have separate preouts for the sub, front and rear speakers. I would not recommend using the sub preout as your signal for both the speakers and subwoofers. The reason for this is that your headunit has some basic EQ built into it which will effect the signal. If you use the sub preout only, you will loose many of those features... plus any time you change the EQ for the sub, you'll also be doing the same for all the speakers. You're going to be using a lot of power, so I think you should run the thickest wire you can afford. you can also have multiple runs of smaller gauge wire if you prefer. I have 2 4gauge wires going from my battery to the distribution block and 4gauge wiring from the distribution block leading up to all 3 amps.

thumpin07 wrote: »

Also thought of another question how do i run the rca cables to the amps, i will have three monoblock sub amps and either a 2 or 4 channel amp for the components. so my question is on the back of the hu there is only one preout for the sub do i run one sub amp off of this preout and then go from amp to amp to amp with the rca's or do i run a seperate rcas from the hu to each individual amp, just curious how this works and hwo do u use a 4 channel amp to bi amp the components?

bi-amping means you're powering a set of speakers using two channels. if you look at your cross-over for the mmc6500, you'll see there's two types of inputs that you can switch between: single and dual.

Single means you'll be using 1 channel to power the components. This single channel will power both the driver and the tweeter. Or you can set it to "dual" and send 2 channels to the cross over. In this case you'll be using two sources to power your component set - 1 for the tweeter and 1 for the driver - thus the term "bi-amp". Most people who are into SQ will bi-amp their components b/c it offers more tuning flexibility.

Just a suggestion I might offer; I find it best to do some reading/research on your own so you understand how everything works and then ask questions to clarify an issue or to ask for suggestions. My reason for saying this is because people will generally have biased opinions. Unfortunately, I learned this the hard way. In any case, we'll all be glad to help.

black magic

ps. you might wanna compare the costs of 3 less-powerful amps versus the cost of 1 powerful amp in order to power your subs. It'll save you time, space and a bit of a hassle if you can find one amp that puts out 1500 watts at 3 ohms. By all means do whatever you're most comfortable with, but its always a good idea to consider all the options.

thumpin07

will do i just liek getting as much info as possible, and i was thinking about the space issue myself, but my trunk is plenty big enough for the amplifiers but il compare the cost, that is if i can find one that will put out that much at 3 ohms. i guess odd amount of subs to run.

black magic

thumpin07 wrote: »

will do i just liek getting as much info as possible, and i was thinking about the space issue myself, but my trunk is plenty big enough for the amplifiers but il compare the cost, that is if i can find one that will put out that much at 3 ohms. i guess odd amount of subs to run.

If space isn't an issue and cost isn't a problem, I'd definitely go with 3 amps. It looks much cooler than just one amplifier. than 1 :cool: Plus if something was to happen to the amp and you only had one, you'd be without bass while its getting repaired or replaced, whereas if you have 3 amps and only one of them encounters a problem, at least you'll still have another 2 amps you can still use. Plus, they'll probably be easier to sell when its time to upgrade

The only thing I can think of off the top of my head is RF's higher end amps and I also think Hifonics has some powerhouse amps as well. Since I'm not an SPL guy, I'm not really sure which amps provide a ton of power.

thumpin07

gotcha there im going for a somewhat mix of spl and sq, i dont knwo if i want a ported box or sealed box though

black magic

If you want to be crackin' the pavement, build a ported box thats tuned to a low frequency. Since I'm more of an SQ guy, I'd go with a sealed enclosure. My subs sound really nice and they'll play pretty loud for my taste.