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#### vasyachkin

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derivation can be found here:

http://www.avsforum.com/avs-vb/showt...8#post17002458

i have edited this post because it used to be wrong. apologies to NEO Dan, Health Nut and Looney Bomber who replied to the original post with incorrect formula

Vasyachkin's Law States:

efficiency of the system is proportional to BOX VOLUME X RESONANCE FREQUENCY CUBED / SYSTEM Q

Hoffman's law is essentially a special case of this for when the Q is not allowed to change and instead ASSUMED to always be some "optimal" value such as 0.7

Vasyachkin's law by contrast ( hopefully ) makes you realize that maximizing performance is not only about building a bigger box, but also using high-BL subwoofers ( high BL results in low Q )

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E = mc^2

#### Looneybomber

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
Quote:
Originally Posted by vasyachkin /forum/post/17002583

efficiency of the system is proportional to ( BOX VOLUME X CORNER FREQUENCY / SYSTEM Q )

4.0ft * 34.4hz / .684 = 201.2

2.0ft * 44.2hz / .856 = 103.3

Does that even tell me anything?

#### NEO Dan

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Beware the electromagnetic crane Iron Man....for you are a flaming Tard

JBL 2226H

Box 1033.14743772165"³ Q=1

Yellow: stock

Purple: BL increased from stock 19.2 to 84.130184832793515026990558638203

#### NEO Dan

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

Same drivers

Yellow 1033"³ Q=1

Blue 853"³ Q=2

Purple 12"³ Q=1

#### vasyachkin

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by the way by corner frequency i meant resonance frequency.

and i forgot the cube ( x^3 ) so really its:

efficiency of the system is proportional to ( BOX VOLUME X RESONANCE FREQUENCY CUBED / SYSTEM Q )

but anyway let's wait till i am not stoned then i will think about it some more.

i am defintiely onto something here i just haven't had the time to think about it. i was running out when posted this.

#### NEO Dan

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Quote:
Originally Posted by vasyachkin /forum/post/17003512

but anyway let's wait till i am not stoned then i will think about it some more.

LOL, that'd be a good start

#### vasyachkin

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
Quote:
Originally Posted by NEO Dan /forum/post/17003550

LOL, that'd be a good start

dan with the cube in place the only part different from hoffman's law is the part that deals with Q.

#### NEO Dan

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If that means more BL it's not gonna work

#### vasyachkin

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ok i had some sleep. bring it on. i say:

efficiency of the system is proportional to ( BOX VOLUME X RESONANCE FREQUENCY CUBED / SYSTEM Q )

what say you ?

i had one hypothetical scenario worked out in another thread. now let me do another one. in this case we will decrease box volume by factor of 4.

decreasing box by x4 makes resonance go up by x2. it also makes Q go up by x2. we have ( 1/4 * (2^3) / 2 ) = 1. in other words efficiency does not change as you would expect.

so once again the point of all this is to say that for system efficiency in a given box volume the resonance frequency is not the only factor that determines efficiency. Q is also a factor.

in other words when you need to get the most bass out of a small box Low Q, high-BL subs are inherently more efficient.

#### Johnsteph10

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
Quote:
Originally Posted by vasyachkin /forum/post/17004715

what say you ?

Stop doing drugs. Get a job.

#### vasyachkin

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
Quote:
Originally Posted by NEO Dan /forum/post/17003589

If that means more BL it's not gonna work

of course it will silly.

try model a sub with zero BL see how much efficiency you get

#### vasyachkin

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so can anybody find a case inconsistent with this formula ?

come on i did the thinking - you do the modeling. it is only fair

#### NEO Dan

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Look up

fixed box size and fixed Q examples

#### vasyachkin

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ok your first screen with quadruple MMS and quadruple BL proves i am right. first efficiency goes down due to lowering of resonance frequeny then it is raised back due to lowering of Q ( same resonance frequency )

second screen i dunno what the **** you were doing

#### NEO Dan

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
Quote:
Originally Posted by vasyachkin /forum/post/17006963

ok your first screen with quadruple MMS and quadruple BL proves i am right. first efficiency goes down due to lowering of resonance frequeny then it is raised back due to lowering of Q ( same resonance frequency )

But it's not more efficient. It SUX

Quote:
Originally Posted by vasyachkin /forum/post/17006963

second screen i dunno what the **** you were doing

Second set is where the enclosure volumes are manipulated to achieve the system Q you claimed

Stock Q= 1 = 1033"³

4xMMS Q= 2 = 853"³

4xMMS+BL Q= 1 = 12"³

So basically you would have a closed back midrange with MASSIVE BL and MMS

#### vasyachkin

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in the first one my purple trace is clearly kicking your ass at 10 hz

in the second one why did you reduce the box volume ? i said increase MMS by x4 then boost BL by sqrt(2). i didn't say decrease box volume. not in that logic experiment.

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