figure out DB

[foomasta69 10+ year member]

how do you figuire out the db liek ppl do..

example

3 x SWS-1242Ds should be louder than 2 x CVR12s ...

2 x CVR12s - 86.7 + 10*log(400*2) + 10*log(2) = 118.725 dB

whats log mean and all that stuff...

all i kno is that the 86.7 is the sub db sensivity

Click to read more...

 

[PV Audio 5,000+ posts]

log = logarithm. are u familiar with the laws of exponents? if so, u should be able to do logs. me personally, i find them difficult.

 

[foomasta69 10+ year member]

hellllll no help me hahaaa

 

[PV Audio 5,000+ posts]

*whips out math binder*

 

[foomasta69 10+ year member]

lol goodddd //content.invisioncic.com/y282845/emoticons/cool.gif.3bcaf8f141236c00f8044d07150e34f7.gif

 

[JimJ 5,000+ posts]

Don't try to figure out overall SPL using speaker sensitivity...for subwoofers, it's almost worthless.

Use Sd*Xmax (displacement) instead. Even that is a very, very rough estimate.

 

[PV Audio 5,000+ posts]

Don't try to figure out overall SPL using speaker sensitivity...for subwoofers, it's almost worthless.
Use Sd*Xmax (displacement) instead. Even that is a very, very rough estimate.

but u DO have to agree that it gets u at least closer to a semi-realistic # than just half-assed guessing //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[JimJ 5,000+ posts]

but u DO have to agree that it gets u at least closer to a semi-realistic # than just half-assed guessing

Maybe.

He didn't specify whether those numbers were taken @ 1V/meter (industry standard) or 2.83V/meter (used by companies like Infinity to inflate their numbers)...so it could be 3dB off in either direction.

 

[PV Audio 5,000+ posts]

Maybe.
He didn't specify whether those numbers were taken @ 1V/meter (industry standard) or 2.83V/meter (used by companies like Infinity to inflate their numbers)...so it could be 3dB off in either direction.

more likely than not, 1 volt.

 

[RandyJ 10+ year member]

If yoru not familiar with log, think about it this way.

a^c=b

So logab=c

A being the base.

So you are finding out what© times the base will give you c.

 

[RandyJ 10+ year member]

Also, do a search on log rules and laws, youshould find a way to condense logs when you are adding, subtracting, multiplying.......