When will doubling the power really add 3dB?

[Nelson9937955 10+ year member]

It would be in a trunked 2 door coupe. Sealed enclosure. 1.5 cu ft for the 1 vs 3.0 cu ft for the 2 subs.

 

[SPL140.2 5,000+ posts]

in a trunk in my opinion go with 2-12"s itll hit lower

 

[Nelson9937955 10+ year member]

But i kind of take it from the tone of your comments that there "probably" wouldn't be a huge difference in that comparison or did i read you wrong?

The 2 12" setup would cost me about 150.00 more than the 1 12" setup.

 

[SPL140.2 5,000+ posts]

the 2-12's will hit deeper in a sealed enclosure if you were talkin about a hatch id shoot for the single 12 if you want it louder port the enclosure.

 

[newusername 10+ year member]

3db is twice as loud

3dB is roughly when you perceive an increase in loudness. 10dB is twice as loud.

There are a lot of factors to consider, but in a general sense, you might see the 3dB increase if you have not run into power compression and you're playing a frequency in a physical position where there is little-to-no destructive interference.

 

[Chevyaudio 5,000+ posts]

I think that theory works when your dealing with over 5000 watts....

nope...and the old 3db boost theory probably is more suited to lower power applications, like 300watts to 600 watts. If you are using 5000 watts depending on number of subs and the drivers used, more than likely you have almost reached power compression, where you hit a point of dimishing return. By adding a second amp...I only gain like 1.2.

 

[ghart999 10+ year member]

3dB is roughly when you perceive an increase in loudness. 10dB is twice as loud.
There are a lot of factors to consider, but in a general sense, you might see the 3dB increase if you have not run into power compression and you're playing a frequency in a physical position where there is little-to-no destructive interference.

How would I know if I have reached the subs power compression? Also part of the concern is that my car rattles like a mofo at 143dB. I have gobs of sound deadener too. I suppose that a 2dB increase would be pretty impressive. I wish I could juts buy the amp and try it and if not worth it then return it.

 

[ghart999 10+ year member]

nope...and the old 3db boost theory probably is more suited to lower power applications, like 300watts to 600 watts. If you are using 5000 watts depending on number of subs and the drivers used, more than likely you have almost reached power compression, where you hit a point of dimishing return. By adding a second amp...I only gain like 1.2.

But if a sub is rated at 1000w RMS and I am giving it 500, wouldn't the sub's power compression still be about 500 watts away from my current offering?

 

[Lakota 5,000+ posts]

The theory of a 3db gain comes from log equations starting that doubling the sound intensity = 3db.

 

[newusername 10+ year member]

How would I know if I have reached the subs power compression? Also part of the concern is that my car rattles like a mofo at 143dB. I have gobs of sound deadener too. I suppose that a 2dB increase would be pretty impressive. I wish I could juts buy the amp and try it and if not worth it then return it.

More about power compression:

http://www.soundsolutionsaudio.com/forum/index.php?showtopic=7112

 

[SPL140.2 5,000+ posts]

But if a sub is rated at 1000w RMS and I am giving it 500, wouldn't the sub's power compression still be about 500 watts away from my current offering?

depends upon the sub being used, some woofers will reach there power compression before the rated rms spec and others subs exceed there rated specs.

 

[audioholic 5,000+ posts]

I think that theory works when your dealing with over 5000 watts....

This coming from the guy with $5k SPL subs. Dude c'mon, you should know better than that. lol

 

[dleccord 5,000+ posts]

3db is twice as loud

that's definitely wrong.

a 2-3db boost you should feel it more and it will be louder example turn your head unit to volume 10 than turn it up to volume 20, can you feel it more is it louder?? //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

i dont think it works that way. my old alpine deck was quiet up until volume 23. once its 23/24, its definitely louder, but not in a linear way. i didnt measure my deck with a meter so i cant say for sure but my deck doesnt seem to increase in a linear (ie. doubling from 10 to 20). exponential maybe? i didnt amp my speakers btw.

3dB is roughly when you perceive an increase in loudness. 10dB is twice as loud.
There are a lot of factors to consider, but in a general sense, you might see the 3dB increase if you have not run into power compression and you're playing a frequency in a physical position where there is little-to-no destructive interference.

correcto! 10db is considered twice as loud to the ear.

 

[SplChoice- 10+ year member]

from what i heard 6db is twice as loud but i can be wrong 3 db is twice as much power

 

[phantom240 5,000+ posts]

depends upon the sub being used, some woofers will reach there power compression before the rated rms spec and others subs exceed there rated specs.

So, let em get this straight (I never really understood the effects of power compression) that power compression reduces the gains in output from a sub past certain power levels, and may actually reduce output?