School me on car audio

[tiger_handheld]

I'm trying to put together a sub and amp and i'm trying to figure out how to buy the correct 'amp wiring kit'. I've reached out the two favourite audio sponsors here and they've given me their quotes/advise on how it should be done. I figured I should at least learn a thing or two even though I will take my car to one of them.

So, the amp has the following specs:

4-ohm Power:
200 watts x 1

2-ohm Power:
300 watts x 1

1-ohm Mono Power:
500 watts x 1

Peak Power:
1000 watts


The wire kit has the following specs:

• 8 Gauge OFC Amp Kit Power/Ground Amp Install Kit
• HEPTAflex ultra-flexible MAXX blue power wire
• 735 strands of high-grade pure copper
• For systems up to 700 watts RMS
• FLEXIbrass AGU fuse holder with 60amp AGU fuse installed
• Tinned copper resists oxidation
• Easy-open perforated packaging

This is all french to me. Can someone explain the following:

1-Peak power vs 4ohm power? Do I not get 1000W? I only have 1 sub



2-What is RMS power and how does that convert to 4ohm, 2ohm, peak power?



3-Gauge I presume is the thickness of wire. Is thicker the better?

4-I was told Oxygen Free is better than Copper Clad Alum. Whats the chemistry behind this?

[LenovoTurbo]

Originally Posted by tiger_handheld

I'm trying to put together a sub and amp and i'm trying to figure out how to buy the correct 'amp wiring kit'. I've reached out the two favourite audio sponsors here and they've given me their quotes/advise on how it should be done. I figured I should at least learn a thing or two even though I will take my car to one of them.

So, the amp has the following specs:

4-ohm Power:
200 watts x 1

2-ohm Power:
300 watts x 1

1-ohm Mono Power:
500 watts x 1

Peak Power:
1000 watts


The wire kit has the following specs:

• 8 Gauge OFC Amp Kit Power/Ground Amp Install Kit
• HEPTAflex ultra-flexible MAXX blue power wire
• 735 strands of high-grade pure copper
• For systems up to 700 watts RMS
• FLEXIbrass AGU fuse holder with 60amp AGU fuse installed
• Tinned copper resists oxidation
• Easy-open perforated packaging

This is all french to me. Can someone explain the following:

1-Peak power vs 4ohm power? Do I not get 1000W? I only have 1 sub



2-What is RMS power and how does that convert to 4ohm, 2ohm, peak power?



3-Gauge I presume is the thickness of wire. Is thicker the better?

4-I was told Oxygen Free is better than Copper Clad Alum. Whats the chemistry behind this?

Peak power is the power that may be reached at one point so it does not matter at all. RMS is the continuous power that it will run at.

The RMS depends on your subwoofer configuration. Since your amp is 1 ohm stable, you would want a 2+2 ohm dual voice coil subwoofer. Wired in parallel would put you at 1ohms. When subwoofer is wired at 1 ohms, it will be driven at 500 watts.

Yes thicker wire would be better, but for 500 watts, a true 8 gauge is good enough.

[gramser57]

I would go straight to OFC 4gauge power wire, it would give you an option to upgrade to a more powerful amp down the road.

[tiger_handheld]

Do do you compare RMS to wattage at 1ohm then? Is 1 ohm the true power of the amp?

Wire parallel? 2 + 2 ohm? What? Is there perpendicular wiring? What if its 4 + 4? I'm lost on this point.

4 gauge vs 8 gauge. Lower the number thicker the wire?

[Volvo-brickster]

Shameless plug for an amp if you want one

http://www.revscene.net/forums/69576...block-amp.html



2 and 1 ohm stable

[gramser57]

Originally Posted by tiger_handheld

Do do you compare RMS to wattage at 1ohm then? Is 1 ohm the true power of the amp?

Wire parallel? 2 + 2 ohm? What? Is there perpendicular wiring? What if its 4 + 4? I'm lost on this point.

4 gauge vs 8 gauge. Lower the number thicker the wire?

1ohm is the lowest impedance you can safely run the amp, the lower impedance the more watts in rms the amp will produce.

Dual voice coils on subs will give you options to wire the final impedence. Example on a dual 2 ohm voice coil subwoofer you can wire the subs in either series or parallel to give you 1 ohm or 4ohm options.

Lower the number the thicker the wire.

[tiger_handheld]

My sub has these following specs:
Size: 10in
Power Handling
(RMS/Peak): 275/550 watts
Nominal Impedance:
Single 4-ohm or Dual 4-ohm
Voice Coil Size: 2 in
Frequency Response:
33Hz - 500Hz (Single)
33Hz - 500Hz (Dual)
Sensitivity: 86dB
Cutout Diameter: 9 1/8 (230.1mm)
Mounting Depth: 5.25 in
VC Impedance: 4 ohm + 4 ohm
Test Impedance: 1.6 ohms
Fs: 33 Hz
SD: 330.06 sqCM
Vas: 39.7 Ltr
Cms: 256 µM/N
Mms: 98.5 g
BL™: 7.44
Qms: 4.85
Qes: 0.566
Qts: 0.51
No: 0.2%
Spl: 86 dB
Xmax: 9.5 mm

Since its only 1 sub, and it says 4+4 ohm, can it still operate at 1ohm? Which means to power this sub 500W sub the amp will put out 500W and the 8 guage wire kit is ok because it can handle upto 700W?

Also, series wiring is christmas lights right? Where one powers the other?


Oxygen Free vs. CCA - What makes Oxygen free better?

[gramser57]

This is wired in Parallel, the lowest you can wire too is 2ohm. If you wired in series it would be 8ohm.
Oxygen Free Copper VS Copper Clad Aluminum. Copper is a better conductor than aluminum which in return will have steadier voltage feeding your amp. If price of wire is a concern you can pick up welding wire at princess auto for dirt cheap.

Are you running a ported or sealed enclosure?

[Lomac]

I've used welding cable in the past. Only downside is that it's more of a solid cable than strand, so trying to get it around tight corners is a PITA.

That's about the extend of my car audio knowledge.

[Soundy]

Originally Posted by tiger_handheld

So, the amp has the following specs:

4-ohm Power:
200 watts x 1

2-ohm Power:
300 watts x 1

1-ohm Mono Power:
500 watts x 1

Peak Power:
1000 watts


The wire kit has the following specs:

• 8 Gauge OFC Amp Kit Power/Ground Amp Install Kit
• HEPTAflex ultra-flexible MAXX blue power wire
• 735 strands of high-grade pure copper
• For systems up to 700 watts RMS
• FLEXIbrass AGU fuse holder with 60amp AGU fuse installed
• Tinned copper resists oxidation
• Easy-open perforated packaging

This is all french to me. Can someone explain the following:

1-Peak power vs 4ohm power? Do I not get 1000W? I only have 1 sub

As already noted, 1000W is the peak power that the amp can deliver for a short period. The other ratings are "RMS continuous" power.

2-What is RMS power and how does that convert to 4ohm, 2ohm, peak power?

RMS (Root Mean Square) is a method of averaging that gives you the "real" power of an AC waveform.

Power is derived from the formula P=VI, or voltage times current. At a given voltage, current is derived from Ohm's Law, I=V/R, or voltage divided by resistance. So power can be calculated using P=V^2/R, or voltage squared, divided by resistance.

As you can see, as the resistance becomes less, the power across it increases (because you're dividing it by a smaller number). Now in theory, halving the resistance should double the power; however, there are numerous design factors that may limit the REAL increase in real-world situations - current capability (lower resistance means more current draw, which can cause supply voltage to drop, and also generates more heat), power supply design, types of output stages, the desire to stay below a certain distortion level, and others.

One important thing to note: these calculations are based on DC resistance, while speakers are a very reactive load, and the ACTUAL resistance (or impedance, properly) they present to the amp will vary depending on the frequency... which is another thing that can affect the real-world output.

3-Gauge I presume is the thickness of wire. Is thicker the better?

4 gauge vs 8 gauge. Lower the number thicker the wire?

Correct. If you want to bend your brain a bit, details are here: http://en.wikipedia.org/wiki/American_wire_gauge

4-I was told Oxygen Free is better than Copper Clad Alum. Whats the chemistry behind this?

Put simply, the more copper, the more efficiently the cable will carry electricity. Aluminum is a fair conductor, but not as good as copper. For short runs, there won't be a noticeable distance, but for longer runs and higher current draw, the added resistance of CCA will result in voltage loss at the the amp end.

Originally Posted by tiger_handheld

Wire parallel? 2 + 2 ohm? What? Is there perpendicular wiring? What if its 4 + 4? I'm lost on this point.

The two types of circuits here are parallel and series (not perpendicular). When dealing with resistance or impedance, you calculate total resistance of a series circuit by simply adding the two numbers... so two 2-ohm coils in series would be 4 ohms.

In parallel, you add the reciprocals of those numbers then take the reciprocal of that, ie. Rt = 1/(1/R1 + 1/R2)... so two 4-ohm coils in parallel would be 1/(1/4 + 1/4) = 1/(1/2) = 2 ohm. Easier way to think of that last step is just to flip the result... so 1/4 + 1/4 = 1/2, and flip it over (2/1).

[Soundy]

BTW, there's a lot of really great info here, arranged in a sort of "tutorial" format that you can work your way through, learning the basics and then building on that as you go: Car Stereo, Mobile Video, Navigation

[tiger_handheld]

Originally Posted by gramser57

Are you running a ported or sealed enclosure?

I have a sealed box. After reading, I realized I didn't want the big BOOM rather more clear bass, and sealed offered that. Hopefully the amp will be powerful enough to run the sub as a result.


Also, just want to say THANKS! to everyone that's been answering my questions. Hopefully, this thread will help another noob learn as well..

[tiger_handheld]

So I get the sub to amp wiring now... I think!!

How does the power wire for the amp play the factor?

I presume thicker wire is better because it has more strands?
Also using my example, the 700W wire will be reasonable because the sub/amp max power is 500W.

With that in mind, is the constraint usually the sub? Meaning if the Sub had 1000W but amp had 2000W and the wire had 3500W, no matter what the, the most wattage from the sub is 1000W? If the person had two 1000W subs wired in parellel, the sub would be 500? (assuming 4ohm = 1000 , 2ohm = 500 , 1ohm 250 - is this even a possible?)?

[Jmac]

Originally Posted by tiger_handheld

So I get the sub to amp wiring now... I think!!

How does the power wire for the amp play the factor?

I presume thicker wire is better because it has more strands?
Also using my example, the 700W wire will be reasonable because the sub/amp max power is 500W.

With that in mind, is the constraint usually the sub? Meaning if the Sub had 1000W but amp had 2000W and the wire had 3500W, no matter what the, the most wattage from the sub is 1000W? If the person had two 1000W subs wired in parellel, the sub would be 500? (assuming 4ohm = 1000 , 2ohm = 500 , 1ohm 250 - is this even a possible?)?

The number of strands doesn't really matter as far as the current-handling capability or resistance of the wire (it'll make an insignificant improvement). What matters is the cross-sectional area (or, more accurately, the circumference). More strands will generally result in a more flexible wire, however, so if you have to make a long run with many turns, more strands can make it easier to route the cable. But yes, thicker is better as a general rule of thumb, but you can go too big (won't fit in your amp, difficult to get through your vehicle, etc.).

Speakers don't have "watts." The rating is simply how much power the sub can handle.

The amplifier's rating is how much power it can produce, usually advertised with a given input voltage (from your alternator/battery) at a given distortion level.

[gramser57]

Originally Posted by tiger_handheld

With that in mind, is the constraint usually the sub? Meaning if the Sub had 1000W but amp had 2000W and the wire had 3500W, no matter what the, the most wattage from the sub is 1000W?

RMS rating for a sub is its thermal limits before the voice coils heat up and fry, peak is what it can handle for short bursts.

The reason why I ask about your enclosure is the sub specs that you posted is aligned better for a ported box.

[Cman333]

I've guessing this is for the sub won from us on FB. You basically need a 2ohm stable mono amp that pushes around 300RMS. Depending on the amp and it's current draw likely an 8AWG OFC kit will be sufficient. Lower the "GAUGE" wire, the thicker the wire is. Don't confuse AWG (AKA American Wiring Gauge) with GAUGE. AWG is standardized. Most no name companies use thick insulation but the wiring inside is much thinner. So what they'll call "4 gauge wiring" is really more like 8AWG or less.

Just remember it takes power to make power. If you have a huge amp and use thin wiring, yes it will work, but not properly. Think like a fire hose vs a garden hose. Which is gonna be able to supply more water (Or current).

Like one other member said, I would recommend 4AWG to give you room for expansion down the road. Down the road you may want to add a speaker amp or a bigger sub + sub amp. Price difference is marginal. That way if you do upgrade you don't have to reinstall the power wire again.

[finbar]

The length of power supply conductor matters.




Perry Babin has a useful explanation here with a couple of handy calculators.