Matching An Amp (Newb Here)

[Improv]

Hello Guys, Just got my first car a 2010 Polo, cost me £4000 1 downside is that the sound system is factory fitted. I have £1000 budget which I think is decent.

My cousin who also has got his car recently now has a 1200 watt enclosed sub which he thinks is the dogs bullocks (British expression). I have done a small amount of research and from what I see the big number (1200) is usually the peak power which from what I understand is just what it can handle for short bursts (Don't know what a short burst is 3, 30 seconds?)

The magic number we need to look at is the RMS power as this is what it can constantly deliver if I am not mistaken. Now from what I've seen is that these low quality cheap rubbish (his was £80) is that they boast huge numbers but only have like 200-300 RMS (I have seen 350 RMS but not at £80).

So what I want to do is pretty simple get a sound system in my Polo which will literally rattle his little Peugeot 107 from down the road

I have done some looking around and found these:

"Precision Power PPI PC.12 1600W"

They say 1600 Watts Peak but RMS is 800 Watts and Impedance is Dual 2 ohms, So I want 2 of these (Obviously).

I am not a Bass Junkie I would also like to get some normal speakers for the highs and mids and not be drowned out by the lows from the subs.

What Speakers to match the subs so I don't look like a bell-end (British expression)

 

What Amp do I get? I get confused with all the 2 ohms and 400 4 ohms at 900 and stuff like that...

Click to read more...

 

[jrdnhsnbrg 10+ year member]

Do you know the conversion factor to USD by chance? I have no idea what you're working with.

1. Completely ignore peak power, RMS and impedance is all you have to worry about.

2. If you want to run 1600W RMS you will probably need to do the Big 3, maybe a second battery and if you don't get a second battery a strong front battery.

3. I feel like you'll get what you pay for with those subs, although I could be wrong. I don't hear of many people running Precision Power subs, their amps are pretty nice though.

Hopefully someone more experienced than I will chime in here //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Jeffdachef 5,000+ posts]

1000 British Pounds Sterling equals

1596.80 US Dollars

with 1.5k dollars, you can do some serious damage.

i know in UK things are more expensive and its going to be hard finding good underground brands to choose from unless you go to SPL competitions there. I would start off with a good pair of component speakers for the front stage with a 2 or 4 channel amp. PrecisionPower - Products - Amplifiers - Phantom - P900.4 this amp should do the trick fine.

As for subwoofers, You will soon find out that numbers dont mean much Compared to how well the subwoofer is built. here's a link to some reliable brands.

Sub Woofers - SSA STORE

Fi Car Audio, Custom Car Audio, Made in the USA | Join the Revolution!

Subwoofers

be sure to check out the monoblock subwoofer amplifiers on those sites as well they are very high quality and dependable to put out a lot of rms power.

wire kits should cost you 120 pounds for the 4 channel and sub amps. go for knukonceptz, stinger or rockford.

Now the question is, do you want to keep your head unit stock or do you want to change it out for a headunit that has enough RCA outputs to run all this?

 

[Jeffdachef 5,000+ posts]

also the thing you really need to consider before buying subwoofers is how much space in your trunk do you really want to give up? How loud you get is based on your subwoofer's enclosure design and most subs do not like/cannot get loud in small boxes. The design is very important too. If you are good with woodworking, you can buy a design on this forum and build the box yourself or have someone else build it. You dont need to have a lot of watts in your system to get loud, some lower powered quality subs in a good box will definitely smash your friend's system and probably a lot of other systems in your city.

 

[Improv]

The simple answer is Yes, I don't have a choice but to change the head unit.

EDIT: I wasnt planning on having a box, I was thinking of using the shelf on the boot (Re-enforced with fibreglass and stuff) A guy in my workplace got a new shelf totally custom made was really heavy and was wrapped in leather, a really well done job.

 

[dtbingle]

You have posted a lot of questions in one thread and we don't have too much to go on. For starters, figure out what your preferences are on some of the questions below.

1) How much trunk space are you willing to sacrifice? Roughly get dimensions (L x W x H) of the area you have to work with. From there it'll be easier to decide on how many subs and what size. Since you said you want to rattle his car from down the street, you should probably be looking at a ported sub enclosure, but keep in mind, ported set ups require usually close to double the space. EDIT: From your follow up posts it seems like you're going with a fiberglass install. I hope you're familiar with working with it or are going to pay someone who does because it can be messy and a pain to do right and look good until you've had some practice. Also, the space you mentioned to fiberglass a box (at least what I'm picturing) would be rather small for a ported setup, but rough measurements can prove/disprove that.

2) Do you have an aftermarket radio installed? If not, then you will need line out converters, but they aren't as good as RCA preouts from an aftermarket radio. I recommend looking into an aftermarket raido solution. EDIT: Scratch this since you decided on aftermarket head unit.

3) Since you plan on upgrading your door speakers to nicely match your sub output, you should either get a higher end radio with a high power output or separate amp for them or else you will be drastically underpowering the door speakers. A lot of average setups have a 1-channel amp (mono amp) to power their sub and then something like a 4-channel amp to power their door speakers. Another solution would be to look into 5-channel amps (1 for sub, 4 for the door speakers), but with a 5 channel amp, you may have difficulty getting the power you are looking for.

4) Lastly, I would look up info on your alternator to figure out its current output (in amperes). This will be one limiting factor depending on how many watts your amp(s) will be needing. For example, the alternator in my car has a 136 amp output. To be safe, I'd say 30-40 amps are going towards the car's other functions leaving me with roughly 100amps. Power = Voltage * Current and my battery is usually in the range of 13.5volt - 14volt when running. Power = 14v * 100a = 1400W. So in my situation approaching this 1400W area is when I expect to have to upgrade my eletrical system (2nd battery, maybe capacitor, bigger alternator, larger gauge wires), etc.

As a final note, it doesn't seem like you're very familiar with how things are installed and set up. I would honestly suggest doing a lot of reading online, talking to your friend for help, and/or going to a local car audio shop for advice. Once you've brushed up on the various aspects, then decide on what you want to buy. I really encourage DIY projects, but if you're really unsure of what you're doing and no one you know can help, I would get estimates of the shop install fees.

EDIT: sorry if some questions are repeated, other people beat me to it as I was typing it out

 

[Improv]

You have posted a lot of questions in one thread and we don't have too much to go on. For starters, figure out what your preferences are on some of the questions below.
1) How much trunk space are you willing to sacrifice? Roughly get dimensions (L x W x H) of the area you have to work with. From there it'll be easier to decide on how many subs and what size. Since you said you want to rattle his car from down the street, you should probably be looking at a ported sub enclosure, but keep in mind, ported set ups require usually close to double the space.

2) Do you have an aftermarket radio installed? If not, then you will need line out converters, but they aren't as good as RCA preouts from an aftermarket radio. I recommend looking into an aftermarket raido solution.

3) Since you plan on upgrading your door speakers to nicely match your sub output, you should either get a higher end radio with a high power output or separate amp for them or else you will be drastically underpowering the door speakers. A lot of average setups have a 1-channel amp (mono amp) to power their sub and then something like a 4-channel amp to power their door speakers. Another solution would be to look into 5-channel amps (1 for sub, 4 for the door speakers), but with a 5 channel amp, you may have difficulty getting the power you are looking for.

4) Lastly, I would look up info on your alternator to figure out its current output (in amperes). This will be one big limiting factor depending on how many watts your amp(s) will be needing. For example, the alternator in my car has a 136 amp output. To be safe, I'd say 30-40 amps are going towards the car's other functions leaving me with roughly 100amps. Power = Voltage * Current and my battery is usually in the range of 13.5volt - 14volt when running. Power = 14v * 100a = 1400W. So in my situation approaching this 1400W area is when I expect to have to upgrade my eletrical system (2nd battery, maybe capacitor, bigger alternator, larger gauge wires), etc.

As a final note, it doesn't seem like you're very familiar with how things are installed and set up. There's much more than just buying a sub and amp and throwing it in. I would honestly suggest doing a lot of reading online, talking to your friend for help, or going to a local car audio shop and having it installed there.

EDIT: sorry if some questions are repeated, other people beat me to it as I was typing it out

1 - By rattling his car I was simply meaning I want it to be loud. As for a measurement I will be using the parcel shelf on the boot

2 - Will add an aftermarket

3 - how about a decent Head unit for the door speakers, and the amp for the back subs

4 - The alternator says 90 Amps by your logic I have 50 Amps remaining (just to be safe) and the battery is 12v so I have 600watts

5 - I am not and thus I would like to be sure of what I'm doing rather than pissing down 1000 pounds and claiming ignorance

My flatmate is a mechanic though he has no clue about sound otherwise I'd ask him and my cousin is 18 years old so he knows less than me

So getting a new Alternator upgrade or a new battery isnt really a big deal.

 

[jrdnhsnbrg 10+ year member]

You have posted a lot of questions in one thread and we don't have too much to go on. For starters, figure out what your preferences are on some of the questions below.
1) How much trunk space are you willing to sacrifice? Roughly get dimensions (L x W x H) of the area you have to work with. From there it'll be easier to decide on how many subs and what size. Since you said you want to rattle his car from down the street, you should probably be looking at a ported sub enclosure, but keep in mind, ported set ups require usually close to double the space. EDIT: From your follow up posts it seems like you're going with a fiberglass install. I hope you're familiar with working with it or are going to pay someone who does because it can be messy and a pain to do right and look good until you've had some practice. Also, the space you mentioned to fiberglass a box (at least what I'm picturing) would be rather small for a ported setup, but rough measurements can prove/disprove that.

2) Do you have an aftermarket radio installed? If not, then you will need line out converters, but they aren't as good as RCA preouts from an aftermarket radio. I recommend looking into an aftermarket raido solution. EDIT: Scratch this since you decided on aftermarket head unit.

3) Since you plan on upgrading your door speakers to nicely match your sub output, you should either get a higher end radio with a high power output or separate amp for them or else you will be drastically underpowering the door speakers. A lot of average setups have a 1-channel amp (mono amp) to power their sub and then something like a 4-channel amp to power their door speakers. Another solution would be to look into 5-channel amps (1 for sub, 4 for the door speakers), but with a 5 channel amp, you may have difficulty getting the power you are looking for.

4) Lastly, I would look up info on your alternator to figure out its current output (in amperes). This will be one limiting factor depending on how many watts your amp(s) will be needing. For example, the alternator in my car has a 136 amp output. To be safe, I'd say 30-40 amps are going towards the car's other functions leaving me with roughly 100amps. Power = Voltage * Current and my battery is usually in the range of 13.5volt - 14volt when running. Power = 14v * 100a = 1400W. So in my situation approaching this 1400W area is when I expect to have to upgrade my eletrical system (2nd battery, maybe capacitor, bigger alternator, larger gauge wires), etc.

As a final note, it doesn't seem like you're very familiar with how things are installed and set up. I would honestly suggest doing a lot of reading online, talking to your friend for help, and/or going to a local car audio shop for advice. Once you've brushed up on the various aspects, then decide on what you want to buy. I really encourage DIY projects, but if you're really unsure of what you're doing and no one you know can help, I would get estimates of the shop install fees.

EDIT: sorry if some questions are repeated, other people beat me to it as I was typing it out

From what I've heard it's closer to 60-70% of the rated amperage of your alternator goes towards your car's electrical needs, especially at night and in the cold due to more accessories needing to run like headlights, climate control, defoggers, and your head unit itself. I may be off, though.

 

[Improv]

From what I've heard it's closer to 60-70% of the rated amperage of your alternator goes towards your car's electrical needs, especially at night and in the cold due to more accessories needing to run like headlights, climate control, defoggers, and your head unit itself. I may be off, though.

Not really bothered I can get a 125 Amp battery to sort me out

 

[jrdnhsnbrg 10+ year member]

Not really bothered I can get a 125 Amp battery to sort me out

A battery will only get you so far, you will need a HO alt depending on the stock alt and how much power you want to run.

 

[Jeffdachef 5,000+ posts]

1 - By rattling his car I was simply meaning I want it to be loud. As for a measurement I will be using the parcel shelf on the boot2 - Will add an aftermarket

3 - how about a decent Head unit for the door speakers, and the amp for the back subs

4 - The alternator says 90 Amps by your logic I have 50 Amps remaining (just to be safe) and the battery is 12v so I have 600watts

5 - I am not and thus I would like to be sure of what I'm doing rather than pissing down 1000 pounds and claiming ignorance

My flatmate is a mechanic though he has no clue about sound otherwise I'd ask him and my cousin is 18 years old so he knows less than me

So getting a new Alternator upgrade or a new battery isnt really a big deal.

realistically your car's stock alt should handle up to 1500-2000 rms if you have upgraded your big 3 (adding bigger earth wires in your engine) and add an AGM battery in the back or upgrade the one in the front. A daily system is not going to pull that much amperage all the times and AGM batteries have enough reserve capacity to keep your voltages moderately high and safe. Unless your competing in SPL then thats a different story. Plenty of people have ran 2k systems on stock alts with no trouble at all as long as your voltages are high and stable you should be good.

That being said with the amount of space you said your going to use, i wouldnt go for subs higher than 1000 rms since those tend to want more RMS than needed and need big enclosures. The amp is pretty important, make sure you have a bigger budget for your amp rather than dumping it all on subs. Also your going to need sound deadening for sure.