true?

Hey guys, i was on my honda civic website, and i saw a new forum called car audio. I was reading a few things on there, and ran across this statement.

"For example...let's use the JL Audio W7 series for arguements sake. The 10W7 has an efficiency of 84.3 SPL @ 1W/1M and the 8W7 has a efficiency of 82.7 SPL @ 1W/1M. The 10W7 has a power rating of 500watts continuous which is the recommended power rating for the woofer by JL. The 8W7 has a continuous power handling of 300watts but they recommend their 250/1 to power it. OK, if you take that single 10" and put 1watt of power in it, it will play 84.3db but everytime you double the power that rating will go up 3db so basically with 500watts of power it will play 108.3db. Now do the same with the 8W7, but before you start you add 3db because you will be running 2 8's, so instead of starting with a 82.7 SPL you will be starting with 85.7. Now that number with 500watts of power it will play 112.7db. Doesn't seem like alot but believe me that's a big deal and is very noticeable."

I was just wondering how true that was/is. it makes sense, but i dont think its that easy.

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1990 Honda Civic HB:
Clarion DXZ545MP H.U.
2- 6.5" Power Acoustik interiors
Diamond Audio 600.1 amp
Diamond Audio 15" M6MKII
Pyramid PB881X 4 CH. Amp

What's the website?

Here is a basic scale based on these numbers

84.3 = 1

87.3 = 2

90.3 = 4

93.3 = 8

96.3 = 16

99.3 = 32

102.3 = the square root of an the capacity of your dogs stomach

105.3 = 128

108.3 = 256

111.3 = 512

So either my math is out or their math is out. Maybe they did not factor in the dogs stomach? The principle that they list is correct but it seems the numbers are a little off.

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Top Secret, I can tell you but then my wife will kill me.

Plus due to losses and inefficiencies, it is not always a stricly accurate algorithm. 

And you have to use a schnauzer to get the most accurate dog stomach offset numbers.  If you use the standard golden retriever factor the math comes out closer to the results in the original message.  I think Bose and Sony use a wiener dog as their baseline, which is how they can advertise fake power ratings.

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lmao. u guys are awesome. to rob, the website is www.clubhonda.com 

this is a link to the thread. its about the 4th or 5th post down.

https://www.clubhonda.com/forums/showthread.php?s=&threadid=13442

check it out.

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1990 Honda Civic HB:
Clarion DXZ545MP H.U.
2- 6.5" Power Acoustik interiors
Diamond Audio 600.1 amp
Diamond Audio 15" M6MKII
Pyramid PB881X 4 CH. Amp

DYohn] wrote:

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p>Plus due to losses and inefficiencies, it is not always a stricly accurate algorithm. 

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And that's just the subs side of things.  This isn't taking into account the environment the sub is used in (room transfer functions) or the impact the enclosure will have on efficiency.  For subs, efficiency ratings are thrown out the window as soon as you place the sub in an enclosure.  Also, what frequency are we talking about?  If I can find the impedance peak I can get the sub to be REALLY loud off of one watt.

From what I understand, one company rates their subs at half a meter and in vehicle.  So their numbers are extremely inflated.

Steven Kephart

Adire Audio

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Could that perhaps be Audiobahn with 97db woofers? You don't have to answer that, but I have a hunch. :-)

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New Project: 2003 Pathfinder

kfr01] wrote:

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ould that perhaps be Audiobahn with 97db woofers? You don't have to answer that, but I have a hunch. :-)

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Not at all.  A bunch of chrome and flame designs actually adds efficiency to the driver.  Honest.

Steven Kephart

Adire Audio

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I never knew that... Damn, looks like I have to get rid of my Eclipse SW9122, 'cause there ain't no flames... and no chrome either!

Yer KILLIN' me, Steven!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Dang, well, time to sell my brahmas then for some super high quality efficient Audiobahns! lol

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"I don't play games. I play Nakamichi and that for real yo" - Probably some japanese kid said this in the early 80's trying to sell stereo out of his trunk lol.

but only if you have the stickers too

uthinkuknoaudio wrote:

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Dang, well, time to sell my brahmas then for some super high quality efficient Audiobahns! lol

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We chrome plate the voice coil of the sub to allow even better efficiency.  As for flames, well they will come later.

Steven Kephart

Adire Audio

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I needed a good laugh, does my brahma really have a chrome plate on that coil ? I really haven't looked at that to be sure ... As for the flames, they can make good solder as far as i'm concerned lol.

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"I don't play games. I play Nakamichi and that for real yo" - Probably some japanese kid said this in the early 80's trying to sell stereo out of his trunk lol.

i'll have to send back the eclipse i got coming for a coulpe audiobahns, and do they sell baskets seperate? or even the chrome paint? i figure the more of that i have the louder it will be, im gonna be setting the baskets right next to bare metal of the trunk to get the most out of them.

yeah... Maybe i can get those pyramids to hit 176 db's if i just put more chrome on them and all around them.

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"I don't play games. I play Nakamichi and that for real yo" - Probably some japanese kid said this in the early 80's trying to sell stereo out of his trunk lol.

^^^^
That's possible. But you don't need chrome. If you have enough of there 15in drivers ($25 each?), you can hit whatever Db you want to.

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8"s don't get low enough in their frequency response IMO.

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2009 Pontiac G8 in planning stage
HU: ?
Speakers: ?
Amps: ?

I think they are forgetting about the fact that, although you DO have two drivers, you are not starting with one watt, you are starting with TWO watts - one watt each

Power
1w     84.3          82.7
2w     87.3          85.7
4w     90.3          88.7
8w     93.3          91.7
16w     96.3          94.7
32w     99.3          97.7
64w     102.3          100.7
128w     105.3          103.7
256w     108.3          106.7 (maximum output for one 8 @ 250 watts)
512w     111.3          109.7 (maximum output for two 8 @ 250 watts, each)

The way I figure it, the one 10" will STILL play louder at the same power level than two 8" drivers, even allowing for losses... NUTS! I forgot to figure *MY* Rottweiler's stomach into the numbers!!!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

An 8" woofer is capable of reproducing the lowest range of human hearing, just not as efficiently as a larger cone may do so (in general.)  But frequency response actually has nothing to do with the SPL issue.

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Well in a car's case wouldn't it actually have something to do w/ it?  Forgot the name of what it's called.  Something to do w/ a smaller car means greater spl at lower frequencies right?  I might be wrong.

If you're talking about cabin gain, then yes, it is frequency dependent and different for every car and for every speaker position in the car.  But the power vs expected db performance based on efficiency is not frequency dependent...

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ANy driver/Speaker can produce any signal that you feed it. A 3in driver can reproduce a 5Hz frequency if that's the signal that you feed it. But it does not really matter if the driver can play the frequency, it matters if the Driver can play the frequency audibly, or causes noticable vibrations. BTW, a 3in driver would produce about 25Db at 5Hz. <- that is inaudible.

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