Okay so as it goes with almost every forum there is alot of wonky and misguided information being thrown around. Especially about Car Audio. It seems to be in industry epidemic for retailers, particularly "big box" stores to hand out alot of misinformation to make the sale. I'm going to try to help clear up alot of this mumbo jumbo wihout getting too technical.

I'll start with Speakers.

wattage: The biggest misconseption there is. Pretty much everywhere tells you that wattage is very important and will tell you how a speaker will sound and how loud it can get etc. It's a complete falsehood. Wattage is actually one of the least important factors when choosing a speaker. Wattage rating is merely how much heat a given speaker can dissipate without being damaged. It has nothing to do with anything else. THD, Excursion( XMAX), Frequency response are far more important factors.

Peak vs RMS. Peak wattage mans absolutely little to nothign since there is no standard for measuring this. Some unscrupulous companies will rate 6.5" speakers at 600watts peak. What they neglect to mention is that it is how much power the speaker can handle for 0.5seconds before it cathes fire.

RMS (root mean square) is the actual power the speaker a handle. Always ONLY look at RMS numbers on amps, head units speakers. It's the ONLY accurate power number that has standardized testing. Keeps comparisions apples to apples instead of apples to watermelons


Xmax: very simple and straight forward it's the amount of distance a speaker can travel in one direction. Speakers move both outward and inward an equal amount. Xmax is the measurement of its maximum one way travel. This effects the amount of bass a speaker can produce. (More XMAX isn't always better since a midrange speaker can only play so much bass before causing all the midrange sound to distort a sound jarbled. 5mm Xmax for 6.5" speaker is plenty)

THD: Total Harmonic Distortion. easiest terms it's the loss of quality in sound the speaker suffers. (anything below 3% is acceptable, if your into good sound and have a good ear .5% and below is the good stuff)

Frequency reponse: I'll need a pic to help explain this one.


the verticle column is the speakers output in dB's the horizontal colun is the speakers frequency measured in Hz. at the far left is 20Hz which is really low bass. So ow that few humans can actually hear it. To the right is 20,000hz, ultra high frequency to the max limits of human hearing.

Frequency response is the speakers ability to play at the same level throughout the whole frequency range. As you can see from the Graph above it's all over the place. ranging from high 90's to low 70's. This setup would sound really peaky with some notes being very quiet and other being painfully loud.

Good speakers will have at least a frequency reponse from 80-20,00hz of +/- 3db. Which means the hloudest notes it can play to the quietst notes won't range more than 3 Decibels up or down.


Sensitivity: This is the speakers loudness. usually measured at 1Watt at 1 meter. or 2.83Vrms (which is actually 2 watts a 1 meter or a cheater number) for 6.5" speakers this will usually range from 87 up to 96DB's.
If the rating is 1W 1M then it's how loud the speaker will get listening from 1 meter away giving it a mere 1 watt of power. if it's rated at 283Vrms then the number is actully 3dB's higher than the 1WM rating so when shopping be careful and rememebr that anything rated at 2.83Vrms will always artificially see 3D's louder.

Last but not least. Listen to the speakers everyone's hearing is a little different and what may sound great to one person can sound peaky and crappy to the next. and aoid any speakers that have rediculously high wattage ratings. like 250watts peak and up.. these are usually the crapyiest the market has to offer some companies just rate them to seem like they are good.

Always feel free to PM me if there's any questions or reccomendations you need. I'm always glad to help debunk missinformation and help out.

I'll add more on Head units and amps later it's enough writing for today

 

I was with you up until this point. It seemed to be a very lazy explanation for a very broad and irresponsible statement. Just avoid a speaker that boasts 250watts and up? I will assume that you were talking about coaxial or component speakers and not subwoofers since that would make no sense whatsoever otherwise. But I think you need to explain the "WHY" a bit more than just to say that companies just rate them higher to make the speakers "seem like they are good". While I will agree that numbers can at times seem a bit inflated, any misrepresentation by the companies would be just that...misrepresentation...and therefore open them up to lawsuits. If they marketed their speakers that way, then that would be false advertising.