anybody know why my friend hit 144 decibals with 2 tens

[nosv6]

my friend also has a 95 camaro an had ultimate electronics calibrate the machine just before they tested it and hit 144 decibals with only 2 tens in a box that he made. the display vehicle they have is a pt cruiser with 4 of the highest rockford 10's you can buy and they only hit 148.

[Snowman]

im pretty sure i heard wrong...and correct me if i am...but every 3 decibals is twice as loud, so 4 decibals would make it more than twice as loud as your friends. don't listen to me, that sounds wrong....anyone else?

[96firebird311]

144db with 2 10"s....... totally possible. Possible with one 10. Ever heard of Nathan Munson? What kind of box was in the PT cruiser? 4 10" Fosgate Power HX2's right? How many watts? That does seem a little low in a cruiser. I have 3 10" PUNCH HX2's (500W RMS each) and only 1000RMS in a small sealed box and I do 145's. Oh, a you wanted to know why too..... It's all in the install. Are both the boxes ported? What are the boxes tuned to? Power in each install? Also, the cabin of the two vehicles are different. Tons of variables. And to be twice as loud is 10db. 3db is said to be "a noticable difference". If you were to double power or the amount of effective cone area then, in theory, you will gain 3db. However, once you get up there in db many other factors come into play. Such as power compression.

[ November 12, 2002: Message edited by: 96firebird311 ]</p>

[RedBird96]

hey nosv6 do you drive a teal camaro with a system?

[v6maro]

a guy with a single 10" hit 157db's before, it's all about the box.

What kind of box does your friend have? custom? pics?

also, what kind of subs?
-Steve

[96firebird311]

Nate has hit in the 160's off one DD 10". No S#!t.

[Jhonathan]

with 2 DD 10s and a crappy kenwood amp i hit 145.9 outlaw, probably 147 with the crossfire, now im in the 50s with my new setup

[nosv6]

they were just middle grade audiobahn's with a home-built vented box, and it is every 10 decibals is twice as loud, 3 is a noticeable difference.

[MTMike]

<blockquote>quote:</font><hr>Originally posted by nosv6:
they were just middle grade audiobahn's with a home-built vented box, and it is every 10 decibals is twice as loud, 3 is a noticeable difference.<hr></blockquote>

I'm not sure where you're getting your info, but you have to double the power to get a 3db increase, and inversely, a 3 db increase requires twice the power. Where do you get 10 db is twice as loud? Decibels are actualy the unit for 'loudness' and it is a logrithmic formula to calculate it.

-Mike

[Big Tymer]

<blockquote>quote:</font><hr>Originally posted by nosv6:
they were just middle grade audiobahn's with a home-built vented box, and it is every 10 decibals is twice as loud, 3 is a noticeable difference.<hr></blockquote>

3 dB is TWICE as loud.... and to gain 3 dB u have to double the watts.. 3dB is also the smallest incriment a human ear can tell in difference...

[nosv6]

that's the technical term for what i just said. :D

[96firebird311]

<blockquote>quote:</font><hr>Originally posted by 96firebird311:
And to be twice as loud is 10db. 3db is said to be "a noticable difference". <hr></blockquote>
There were these two monkeys in a tree. One named Pete and the other named repeat. If Pete fell down, who is left?

:D :D [img]tongue.gif[/img]

[TransNot]

<blockquote>quote:</font><hr>Originally posted by MTMike:


I'm not sure where you're getting your info, but you have to double the power to get a 3db increase, and inversely, a 3 db increase requires twice the power. Where do you get 10 db is twice as loud? Decibels are actualy the unit for 'loudness' and it is a logrithmic formula to calculate it.

-Mike<hr></blockquote>

Actually, according to a study done in the 40's, the human ear hears about 10dB as twice as loud. Of course, this changes from person to person and is completely subjective, but that might explain why he was confused. both decibels and the human ear work on a logarithmic scale, which conviniently matches up pretty well.

-Travis

[Dominic]

We hear logarithmically .

We can hear anywhere from 10 x E-12 to 120dB, 120dB being the "threshold of pain" and 10 x E-12 being the "threshold of hearing" as far as loudness is concerned.

Humans hear best between 1K and 6K, hence why our voices naturally fall in this range. Most people have severe trouble hearing over 16K and below 40Hz... much of what is heard below 40Hz is actually felt, its called bone resonance, and its not technically heard through the air.

3dB is technically doubling the volume, but it won't sound like its double [img]smile.gif[/img] Most volume controls are logarithmic in nature so that each click sounds like a linear step up in volume. If it wasn't logarithmic you'd turn it up and turn it up and turn it up and then BAM it'd be way too loud and so you could never find the right volume :D (Wouldn't that suck?)

[Dominic]

144dB is doable with 2 10s... but at WHAT FREQUENCY?

I always hate dB drags because they're IMO stupid. Decibals is meaningless unless the woofer is capable of that over a very good range of frequencies. The boxes I design are generally flat from 30Hz-1,000Hz and above. I have some 8" Sonys which sony says will not and should not be ported that are in my home boxes and hit 26Hz @ -3dB, and they're accoustically bass increased because they're aligned as a 4th order Chebvyschev.

So far there is no person on the planet I have met that actually knows how to properly design woofer enclosures such that they're the right size to maximize the frequency response curve of the given woofer. Over and over I see these people building boom boxes, and it sounds horrid. Ported enclosures are the most difficult to design, they require 4th order equation mathematics to calculate the proper box size and resonate frequency... sealed boxes only require a second order equation (think X squared).