Decibel Questions

[cotjones 10+ year member]

Ok, so your post has been answered by numerous people, what more are you looking to find out?
It's a theory, who cares if it actually makes sense or holds true.

Hell, you even answered the question yourself. Obviously you should know that it won't take 512 subs to gain 20 db over 4 subs. There is a point of diminishing returns there.

On top of that, the decibel levels you suggested are unrealistic as well. I've seen stock stereos do in excess of 120 dB. Also, the higher the decibel levels, the harder it is to gain by adding more cone area/power. This is evidenced in extreme vehicles. More does not always = better.

I really don't see how you still can't understand the point of my question which has still NOT been answered.

my question has nothing to do with a particular setup, an enclosed environment, your stock setup nothing...

I am asking for the sake of understanding the principle itself:

(and i will try to put this in as clear of terms as i possibly can since you are such a brain surgeon....)

Does the 3db increase rule ONLY apply when your reference point is a single sub?

re-word of the same question:

using the rule that says, "if you have one sub and add another, you will gain 3db" and accepting that as true...

is the statement "if you have 4 subs and add another 4 you will gain 3db" also true?

 

[UCF_Knight24 10+ year member]

 

[tommyk90 5,000+ posts]

140 db is what is sounds like 100 ft. back from a 747 engine on take off.

150 db WILL cause instant permanent hearing damage. Yea good for sound offs and getting the loudest, but what's the point, you can't listen to it.

You cannot compare a jet engine to a car stereo. A jet engine produces 140 dB at a VERY high frequency which is much more damaging that 140 db in the 30-40 hz range that most car stereos peak at.

So while yes, they both do 140 db, they are nowhere near in the same ballpark frequency wise.

And I know plenty of guys (all ages) who have listened to stereos in excess of 160 dB and still hear perfectly fine. And yes that includes guys in their 50's and 60's who have been listening to 150+ db's for decades.

I really don't see how you still can't understand the point of my question which has still NOT been answered.
my question has nothing to do with a particular setup, an enclosed environment, your stock setup nothing...

I am asking for the sake of understanding the principle itself:

(and i will try to put this in as clear of terms as i possibly can since you are such a brain surgeon....)

Does the 3db increase rule ONLY apply when your reference point is a single sub?

re-word of the same question:

using the rule that says, "if you have one sub and add another, you will gain 3db" and accepting that as true...

is the statement "if you have 4 subs and add another 4 you will gain 3db" also true?

Well, based loosely off the theory, it shouldn't matter what number of subs you start off with. So yes, if you start off with 2 subs then add two more, it should theoretically gain 3 dB. But as I stated before, why even look into this more since the theory has been proven false on numerous occasions.

Why you have to be an ******* about it is beyond me. Perhaps you are looking to take another vacation?

 

[cotjones 10+ year member]

You do realize that SPL is about pressure level of air in an enclosed environment. Also cone area does have marginal effect in dB level . It does not mean that each time you double cone area you will have 3dB's gain.
And whats up with the attitude?

My attitude comes from these 4 pages of ignorant replies and your wrong statements... SPL is about Sound pressure level, period. not in an enclosed environment. It is easier to achieve higher SPL in an enclosed environment but the environment has nothing to do with SPL itself...

(if i go out ontop of a mountain and shout, and it is just a fell whisper when you hear it a mile away, it still has an SPL.

And cone area has a much larger than MARGINAL effect in db level.

In fact, it's one of the biggest factors. aside from cone area and excursion your sub wouldn't make any noise... other factors such as tuning of an enclosure are only secondary factors reguardless of their influence.

And yes theoretically doubling cone area SHOULD give you 3db gain... however, certain physical factors influence this negatively, But my question was assuming that the theory is true.

//content.invisioncic.com/y282845/emoticons/crying.gif.ec0ebefe590df0251476573bc49e46d8.gif some of you are so stupid it makes me sad

 

[Ed Lester 10+ year member]

theoretically, doubling the cone area would add 3 dB. of course with power compression and other factors, this is rarely a reality. But based on that theory, you will need

250 or so.

 

[cotjones 10+ year member]

You cannot compare a jet engine to a car stereo. A jet engine produces 140 dB at a VERY high frequency which is much more damaging that 140 db in the 30-40 hz range that most car stereos peak at.
So while yes, they both do 140 db, they are nowhere near in the same ballpark frequency wise.

And I know plenty of guys (all ages) who have listened to stereos in excess of 160 dB and still hear perfectly fine. And yes that includes guys in their 50's and 60's who have been listening to 150+ db's for decades.

Well, based loosely off the theory, it shouldn't matter what number of subs you start off with. So yes, if you start off with 2 subs then add two more, it should theoretically gain 3 dB. But as I stated before, why even look into this more since the theory has been proven false on numerous occasions.

Why you have to be an ******* about it is beyond me. Perhaps you are looking to take another vacation?

Your first post...

Jesus Christ.
Who let this guy back in?

but i'm the *******

All you had to do was answer the simple question and this thread woulda gone like 4 posts and died, instead you and numerous others just said it was a stupid question and wrestled with me for 4 pages about it.

i have to give it to you though at least you were saying stuff on subject... (unlike the italian superchip)

The application of the question was never a factor, none of you knew the reason i was asking, and thus had no right to question why i was asking it just because it's not completely applicable in the real word.. i made it clear i wanted the answer from a theoretical perspective.

coulda been a simple answer, instead i got this for 4 pages...//content.invisioncic.com/y282845/emoticons/verymad.gif.3f39c5c2fd57527b671fad3efdfac756.gif

 

[01 S 10 10+ year member]

to the OP, go shoot yourself. this is so fckin stupid. get a fckin life, buy some better subs and do your own "real world" testing. Do you really care that it takes 512 subs to get to 121db? wtf your a moron.

 

[cotjones 10+ year member]

to the OP, go shoot yourself. this is so fckin stupid. get a fckin life, buy some better subs and do your own "real world" testing. Do you really care that it takes 512 subs to get to 121db? wtf your a moron.

Thank you for proving my point. I had a perfectly good reason for asking the question, and it's none of your business. Did i ever say anything about having the subs i was asking about?

you are the moron, do you even know what theoretical means?

 

[RKPsk8er 10+ year member]

this is so easy. if 1 sub puts out 100dbs then 1/5 of a sub puts out 20 dbs.

therefore, 1 and 1/5 subs will get you a 120dbzz. //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

 

[cotjones 10+ year member]

this is so easy. if 1 sub puts out 100dbs then 1/5 of a sub puts out 20 dbs.
therefore, 1 and 1/5 subs will get you a 120dbzz. //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif

//content.invisioncic.com/y282845/emoticons/omg.gif.05aa02c3095d6ce9338996654eca0863.gif

 

[Notloud00 10+ year member]

My attitude comes from these 4 pages of ignorant replies and your wrong statements... SPL is about Sound pressure level, period. not in an enclosed environment. It is easier to achieve higher SPL in an enclosed environment but the environment has nothing to do with SPL itself...(if i go out ontop of a mountain and shout, and it is just a fell whisper when you hear it a mile away, it still has an SPL.

And cone area has a much larger than MARGINAL effect in db level.

In fact, it's one of the biggest factors. aside from cone area and excursion your sub wouldn't make any noise... other factors such as tuning of an enclosure are only secondary factors reguardless of their influence.

And yes theoretically doubling cone area SHOULD give you 3db gain... however, certain physical factors influence this negatively, But my question was assuming that the theory is true.

//content.invisioncic.com/y282845/emoticons/crying.gif.ec0ebefe590df0251476573bc49e46d8.gif some of you are so stupid it makes me sad

u need to hook me up with one of those Italian chips lmao

 

[tommyk90 5,000+ posts]

other factors such as tuning of an enclosure are only secondary factors reguardless of their influence.

Not necessarily true. Building and tuning an enclosure correctly can net you WAY more than the 3 dB from your cone area theory.

Hell, on one of my SPL enclosures I tried making the ports 2" shorter and lost nearly 3 dB!

All b.s. aside, i don't know why people even still talk about this theory at all. It has been proven wrong so many times that it should be never talked about.

 

[02parkave 5,000+ posts]

theoretically, doubling the cone area would add 3 dB. of course with power compression and other factors, this is rarely a reality. But based on that theory, you will need 250 or so.

Thought your retarded *** was leaving the site also.

u need to hook me up with one of those Italian chips lmao

Dude, im first in line for one. you know they the shit

 

[cotjones 10+ year member]

Not necessarily true. Building and tuning an enclosure correctly can net you WAY more than the 3 dB from your cone area theory.
Hell, on one of my SPL enclosures I tried making the ports 2" shorter and lost nearly 3 dB!

All b.s. aside, i don't know why people even still talk about this theory at all. It has been proven wrong so many times that it should be never talked about.

I know other factors have a bigger influence in the output, you can take a sub that does 150 db's out of enclosure, and get 80db's, maby less at certain frequencies... i was just alluding to the fact that if you didn't have surface area, you couldn't make sound, period. So it's ridiculous to say cone area has nothing or little to do with SPL. In a particular line of subs it is allmost allways true that in terms of output 18 > 15 > 12 > 10 > 8.

Believe me, I don't for a second plan on applying the theory in a real world situation. I had a simple theoretical question involving the theory. I made this thread to first verify that I had the correct understanding of the theory, and then figure out if it applied in my particular problem.

 

[cdcooper]

You cannot compare a jet engine to a car stereo. A jet engine produces 140 dB at a VERY high frequency which is much more damaging that 140 db in the 30-40 hz range that most car stereos peak at.
So while yes, they both do 140 db, they are nowhere near in the same ballpark frequency wise.

And I know plenty of guys (all ages) who have listened to stereos in excess of 160 dB and still hear perfectly fine. And yes that includes guys in their 50's and 60's who have been listening to 150+ db's for decades.

Well, based loosely off the theory, it shouldn't matter what number of subs you start off with. So yes, if you start off with 2 subs then add two more, it should theoretically gain 3 dB. But as I stated before, why even look into this more since the theory has been proven false on numerous occasions.

Why you have to be an ******* about it is beyond me. Perhaps you are looking to take another vacation?

Db is Db, yes lower fq hurts you more, but stand under a 747 when its landing or taking off you'll see what I mean, its friggen loud.

Yea, I know installers who are now deaf from playing around with too many 150 db systems, your not immune.