Tweeters in Db Drag

They measure SPL in decibels. 

Now, I guess if you got enough tweeters you could make up for the low individual power handling relative to sub bass drivers. 

You lose out on cabin gain help though.  This reason alone is probably enough not to do it.  Other than it sounding like a knife running down a chalk board. 

so your saying it can work just not as good.

Oh good, another reference to sound pressure.  And an opportunity to ask the question I asked on the first page:

stevdart wrote:

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SPL means "sound pressure level", that much I do know.  Do they measure sound pressure or do they measure volume in decibels?  And if they measure volume in decibels, is it correct to say they are measuring SPL?

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How many tweets do I need for my amp (SPL question)?

You need this many like this:

Dude, that's what I needed to know.  Thanks!

..........uh...uh...but Dude, wont that hert my ears?

It's SPL, who cares?

okey, thanks.

............but,  uh....it wont pressurize the cabin!

Good!  There's a benefit I didn't think of.  Now you won't need your SCuBA gear!

kfr01] wrote:

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ASS SPL usually = increase power
TWEET SPL usually = increase drivers

Every time you double power = 3db gain

ALSO

Every time you double the number of tweeters = 3db gain

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kfr01] wrote:

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Every time you double the number of tweeters = 3db gain

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poorman wrote:

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It's not quite that simple.

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It really IS that simple, really.  In order to double something you have to already have something that you are going to double.  You already have a standard.  It doesn't need to be more complicated than that....and

... OH what's this?  Poorman, you didn't finish your correction of kfr01................Do I need to read "Cone Area and Power Myths" to figure out what you had in mind?"

auex - sorry I posted before you could edit your question!

Poormanq45 wrote:

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It's not quite that simple. There are alot of factors that determine exactly what the acoustical output increase will be.
Here's a good reading: Cone Area and Power Myths

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That article is barely worth commenting about.  I'm frankly disappointed that you even thought it was worth mentioning.  

The author states these principles ARE true and then presents minutia limitations that knowledgeable readers are aware of anyway.  Good job, author of that article.  Way to use minutia variables to make newbs who are still learning believe that laws of physics are "myths."  His argument is akin to arguing that $1.00 as currency is a MYTH because the dollar is constantly fluctuating.  Does the dollar fluctuate?  Yes.  Are there an infinite number of variables that COULD affect the value of a dollar?  Yes.  Is it retarded to call the dollar MYTH currency because of these tiny variables and limitations?  Yes. 

I wonder if that author feels smart, pointing out the completely obvious to most people and confusing newbies...

Conclusion:  that was probably one of the most worthless articles I've ever read. 

Poormanq:  I find it funny that you even knew it was worthless.  Indeed, you site the article then contradict it in your analysis.

Look, everyone knows that there are limits to rules.  When limits to rules are very tiny and on the periphery, it only damages new user understanding to go around calling rules  "MYTHS."

sh*t, pretty much every physics course you'll ever take is based on the fact that we except the tiny and peripheral variables.

SO...

DOUBLE POWER = 3db INCREASE
DOUBLE CONE AREA = 3db INCREASE

kfr01] wrote:

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oormanq: I find it funny that you even knew it was worthless. Indeed, you site the article then contradict it in your analysis.

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Poormanq45 wrote:

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Now, I'm thinking(ut ohh), that when you double the cone area, without doubling the power, you are halving the power to each driver which itself would cause a 3dB decrease, which would negate the 3dB increase from the doubled cone area.

Does that make sense?

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1) You are wrong.
2) While you spot a good issue, your characterization of the issue is wrong and oversimplified.

First, the part you're just plain wrong about. IF you were able to keep system power equal THEN the +3db would stand. It would not go to 0.

i.e.   Take 1 woofer being driven by 100w. 2 of the same woofers also being driven by 100w = 3db gain. Forget about wiring for now. It is a 3db gain. The rule takes the halving into acount. 3db gain. 3db gain. 3db gain. You were wrong about that part.

I have to give you credit though, it was a good question. I do wish you would do a quick google search to arrive at answers before making me explain it though. :-) I know you're smart enough to absorb everything you find out there! Since you seem to ask enough of these questions, I highly recommend buying The Loudspeaker Cookbook by Vance Dickason. It has helped me quite a bit and I think you'll eat it up.

Here's the story. Doubling the cone area increases acoustic efficiency by 3db. Ok. End of that rule. Stop thinking about the basic rule. I hear those wheels turning. :-) Shut it off. Please. The double cone area rule is valid.

Ok, NOW, start to consider OTHER RULES or OTHER LIMITATIONS that could change the end result of adding another driver. Let me repeat it. These are OTHER RULES that could change the end result of adding another driver.

One of these OTHER RULES is related to system impedance. When adding a driver, "[combined impedance will be half of a single unit when connected in parallel, and twice the value of a single unit when connected in series. . . . Sensitivity will increase [ANOTHER] +3db for a parallel connection and -3db for a series connection compared to a single driver." Vance Dickason, The Loudspeaker Cookbook, page 40.

So, IF you bought two drivers AND wired them in series THEN the result would be a 0db gain.

Do you see how these are two separate issues?

But, IF you bought two drivers AND wired them in parallel THEN the result would be a 6db gain.

Now, if you have dual voice coils, multiple drivers, and a stable amplifier do you see why I insist on splitting this issue from the cone area issue? It gets complicated!

Other than the complication, however, they really are separate prongs of analysis that need to be addressed one at a time.

hoaxs] wrote:

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f this is so why don't i see it more often.

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Because dogs would be howling for miles around?

kfr01] wrote:

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ther than the complication, however, they really are separate prongs of analysis that need to be addressed one at a time.

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kfr01] wrote:

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ote: Firefox is not very compatible with this forum software.

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