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How can you tell if an amplifier/subwoofers wattage is legitimate??
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A lot of companies out there have been getting worse and worse about overstating or flat out lying about their power ratings. Comparing 1 brand vs another has become very difficult for the consumer these days because of this. CEA, certified, non CEA 2006 Certified, 10 million watts at 18V, 14V, it is all over the place.  Some manufacturers like Pyle Audio , Visonik,  Sony,  Pioneer,  etc,  do this to psychologically  confuse consumers and make them think they have something that they do not.

1 example is the Pioneer TSA-6999 5 way 6X9's box says 480 "watts".. Look up the RMS (Root Mean Square or Continuous) value it is 80 RMS...  
The definition of peak means the product can take that power for an instantaneous burst, it cannot take it for extended play times.  Power Handling is about heat dissipation and magnetic field strength keep that in mind. Why do they list the peak at 6X the RMS?? So the consumer will think they have a 480W speaker,  yet they only really have a 160 watt speaker, or thereabouts. It is all a psychological game to get you to buy it based on some confusing numbers.  

When you compare speakers/subs, magnet is not everything. A big magnet means big power yes, the huge ferrite magnet creates a strong magnetic field. This also means that the speaker will be less efficient and require a higher minimum wattage to run the sub well.  More efficient woofers can run very hard on just a little bit of power, where a less efficient speaker will require a ton of power just to move the coil through the strong magnetic field created by the less efficienct woofer with the larger magnet. SO.

Things to look for in speakers/subs

1. Voice coil diameter (Larger the better)
2. Frame material  (Aluminum is higher end, retains less heat than stamped steel meaning more power handling, and better sound.
3. Cone material (Kevlar, Carbon Fiber, Woven Fiberglass, Poly, Paper, Injected/impregnated paper/poly, etc.) All sound differnet but hard to hear for a noob.. Paper and poly are generally entry level speakers,  The others and the hybrids move higher end.
4. Surround material (rubber and foam have different performance characteristics arguable which is better)
5. Crossover materials (Mylar, Electrolytic, Poly Capacitors) Mylar/Poly are better, Air and iron core inductor coils, air are better
6. Crossover slopes (6dB,12dB, 18.... ) Higher is steeper and is generally better
7. Tweeter material (Aluminum, Silk, Titanium, etc) Silk is softer on the ears, better for Jazz, Classical, R&B . The metal tweets peak out very loud on the high high end so they are good for Rock/Heavy Metal. Titanium and Aluminum are more accurate on an RTA but seem harsh because of that accuracy on the high high end.

Typically over the years manufacturers have use a general rule in rating RMS to Peak values... If the amp/sub is 100 RMS, the peak value would be 200 "watts". Some manufacturers like JL, Orion, Soundstream , Hifonics, higher end, do not even list peak values. I have a couple things to go off of on amplifiers to make sure it is what is says it is..

Ohms Law   V = I  x R     Voltage in volts equals current in amps times resistance
a derivative of that is P = I x E     Power in watts equals current in amps times electromotive force or voltage

 
P(Power in Watts) = I (Current in Amps) X E(Electromotive Force or Voltage). Keep in mind that is theoretic, 100% EFFICIENCY,  meaning an ice cold amplifier with no energy lost to heat.

So if an amplifier has a 100A fuse in it , using P = I x E

P = 100 Amps x  13.5V charging voltage   +/-

P = 1350 Watts

Keep in mind this is a theoretic value.. This means that none of the energy coming through your power wire gets burnt up as heat energy within the amplifier.  If you want to be more precise, most amplifiers are 70-85% efficient in converting input current into output power , or sonic "energy".  This means that for every 1 amp of input current , you will get .7-.85 watts of actual power to your subwoofers.
So fuse ratings are important, if an amp says ity is 1000 watts RMS, it better have at least an 80-90 A fuse in it.. If it has a 50 amp fuse, the amplifier is full of it.

Another important thing is the power/ground inputs.. These are my general guidelines.

8G Power wire   750RMS
4G Power wire   1250 RMS
2G Power Wire 2250 RMS
0/1G Power Wire  2250 RMS +

Car Amplifier Power Wire Guage Chart

There is a lot if other issues surrounding high power systems,  charging system upgrades, caps, batteries, etc.. MAKE SURE you address these issues with ANY system over about 1500  watts RMS total for all amplifiers.  If you do not address the "issues", you will have problems..
If you need some help figuring out what you need, let me know.

Jerry
Owner
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