Explaining the WATTS!

Watts... Watts? Most people will ask you "How much watts can blow out?" just to see how loud it can go.

If your Hi-Fi system has a 10000w amplifier and 10000w speakers will it be loud?

The answer is YES and NO at the same time!

Watts means the amount of power on many things including speakers,but before we talk about power ratings we should mention the magic word --> Efficiency.

Speakers are having Efficiency too.The Efficiency of the speakers is actually called "Sensitivity".

Is getting measured in the labs of the company that makes the speakers by playing a sine wave of the frequencies that the speaker can play with the speaker running on 2.83v (let's say 1w @ 8ohms) and measuring the average SPL (Sound Pressure Level) with a calibrated SPL Meter.

Behind the Sensitivity there's also some other properties that can determine if a speaker will be loud or not,like the Non-Flat Frequency response.

If a speaker has an average Impedance of 8ohms and Sensitivity of 90db with 2.83v,there might be a trap on the Frequency Response of the speaker itself or the Amplifier.

For example if we say a Subwoofer has 95db average sensitivity it might be able to produce 100db with 2.83v at 100hz,but 90db with 2.83v at 50hz,so if we take an spl measurement on 50hz (90db) and 100hz (100db),the average sensitivity will be 95db,but there's a 10db difference between the 50hz and 100hz.

That's why they do a Frequency (20hz-20khz) VS SPL @ 2.83v or a Pink Noise measurement with the speaker and they not measuring the SPL on 2.83v only on a single frequency (for example 1khz).
This is unfortunately happening by many companies that are just looking to sell more and more.

With simple words the higher sensitivity you have,the higher the volume will be with less Watts,but only if the Sensitivity measurement has been done properly.

Let's see some examples and calculations:

Well in this calculation i have a PA Subwoofer with 105db properly measured sensitivity @ 2.83v running on 100w.

While i have a super high efficient Subwoofer,you currently have a Car Subwoofer with 82db Sensitivity running on 10000w.

With some fast calculations that i've made my maximum SPL will be: 125db @ 1 Meter.

If you have a subwoofer that has 82db Average Sensitivity running on 10000w,you can only output maximum: 122db SPL @ 1 Meter.

And remember:

When we are talking about Speakers with same Sensitivity,there's no noticeable difference in real use between "differences" like: 35w and 40w,25w and 50w,70w and 120w,120w and 140w,140w and 180w.

To get fully noticeable difference in SPL you need to give like 10 TIMES the power.
For example,if you have a 100w amplifier playing on the max with a speaker that has 87db Sensitivity (with 2.83v @ 1m),it will output maximum something like 107db,and 108.8db with 150w,so to get 10db more (noticeable difference) you need 1000w to output 117db.

If a speaker is loud that doesn't meaning it's better than a weaker one.
We are judging speakers from there quality,not loudness,high loudness can be given even by a chinese speaker,but quality is unique and rare.

Don't be so sure that your 5000w sound system is louder than my 10w one,because even if your watts aren't a marketing trick and they are real,your system might not even come close to me on an SPL Battle.

If for some reason you are not believing me because you don't know how to calculate this,there's some automated calculators on the Web that can do the trick,just search for "Sensitivity Watts Calculator"...
And before you start blaming the calculations if you see you can't blame me,if everything on your equipment is measured properly,they are an accurate approximitation.

As you can understand we are picking up speakers that are sounding good to our ears,and an amplifier that can drive our load properly without any problem (speakers),not what just mentioning on the box that can output 1000w or something like that.