why is efficiency so critical

[Remotia 10+ year member]

millisecond burps?
try 2 seconds //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

the termlab sensor has a full 1 second sample cycle... which means you better burp for 2 seconds to assure you don't cut it off in mid sample..

personally... efficiency doesn't factor into the top 5 things I look at when judging a woofer for its SPL capability //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Loyd L.

haha, tell me then, what are the 5 top things?

 

[Remotia 10+ year member]

Please do.

http://www.google.com/search?hl=en&q=transducer+power+compression&btnG=Google+Search

 

[audiolife 5,000+ posts]

most subs that are used in comp are what 87-93 db at 1 watt at 1 meter? loudest last year in 2 classes were on the under 90 db side so again not saying sensitivity is irrelivent but if i were to choose between the set up and sensitivity i would lean alot more towards set up. i believe nate munson said a few years back in a 1 sub set up he did that a jl w7 was within .5 -.3db of either a dd 9500 whatever was their top dog that yr. when he posted that he was pretty much the the number 1 guy in 1 woofer set ups. i know the way we measure things changes over the years but on a SIMPLE scale sensitivity numbers dont always figure what they should. there are too many variables to say when i put 3kw to 10kw + on said subwoofer that the more sensitive woofer will always finish on top. at any given point RE, pioneer, DD, kicker, RF,memphis, T3 and cactus sounds all could lay claim to some form or method to being the loudest as im sure there will be others but the deciding factor between all of these is the set up, and i know of guys that just changed woofers and their scores have gone up...and it wasnt because the woofer was more sensitive

 

[Towncar 10+ year member]

I never cared for efficiency ratings..

 

[JimJ 5,000+ posts]

http://www.google.com/search?hl=en&q=transducer+power+compression&btnG=Google+Search

I'll step in here before Loyd cuts a broad swath of pwnage in his wake...

Power compression is not the only issue here. If it were, we'd all be using extremely high efficiency designs derived from PA applications. And the Stroker is based on such a design, I'll admit. Does very well for SPL use.

But there are other forces at work here...for example, will a very high efficiency speaker react well to the kinds of enclosures that are needed to maximize in-cabin SPL? "All things equal" examples are all well and good, but the reality of the situation is is that more things will change than just the efficiency alone. Can't get away from that.

While we're on Google, I've got another handy search...

http://www.google.com/search?hl=en&lr=&safe=off&q=a+clue&btnG=Search

 

[bigbassman Premium Member]

haha, tell me then, what are the 5 top things?

Spider Deflection

Power Compression

Physical clearance rearward for the coil

Physical Footprint of the coil

Inductance and Dcr

in no particular order..

that information will show me a driver is capable of withstanding SPL use, at a frequency most efficient for the design goals, at a power level relevant for the highest score, with a stroke that won't mechanically break it..

sure... the basis of your arguement "all things equal" is dead on... but comeon.. when is all things equal?

never...

that's why you don't see a single company clean house at world finals..

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I just remember comments I made at the show sunday... if you could predict everything correctly using simulations, box programs, and parameters.. there would be no use for shows.. just bring you floppy disc and go "I MADE THE LOUDEST!!!!"

Loyd L.

 

[dustybear300ex 10+ year member]

well i appretiate the input from everybody, but there were some other questions that i listed that no one touched upon...just curious for some answers to those.

thanks

 

[Chevyaudio 5,000+ posts]

LOL, at Jims google search...

Im gonna stay out of this **** fest, its liabel to get nasty. So from this post on, I'll just be watching, and laughing.

 

[luvinthebass 5,000+ posts]

the spl(efficiency) for subs is they test it out in a free-air environment and put 1 watt of power on it and measure in db's from 1 meter away(about 3 feet) and they get that number and post it for that sub's spl, simple and easy, when really the car it's in and enclosure will up it to like over 100 db's easy...

 

[JimJ 5,000+ posts]

I almost forgot to post this:

http://www.adireaudio.com/Files/TechPapers/SPLCalculations.pdf

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[luvinthebass 5,000+ posts]

thanks JimJ

i love math //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Remotia 10+ year member]

Spider DeflectionPower Compression

Physical clearance rearward for the coil

Physical Footprint of the coil

Inductance and Dcr

in no particular order..

that information will show me a driver is capable of withstanding SPL use, at a frequency most efficient for the design goals, at a power level relevant for the highest score, with a stroke that won't mechanically break it..

sure... the basis of your arguement "all things equal" is dead on... but comeon.. when is all things equal?

never...

that's why you don't see a single company clean house at world finals..

//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I just remember comments I made at the show sunday... if you could predict everything correctly using simulations, box programs, and parameters.. there would be no use for shows.. just bring you floppy disc and go "I MADE THE LOUDEST!!!!"

Loyd L.

but who is even talking about spl finials here, I can use mathematical induction to prove my statement.

two drivers in an IB, and you and allow any driver to have any combination of T/S you want expect the SPL of driver 1 has to be lower than driver 2, and the power handling has to be the same or better yet, NO limit! And lets assume at whatever frequency they run at, there is no xmax limit. driver 1 will always be louder than driver two.

Who cares about the spiders or whatever else you’re worried about, hold them constant, that’s my point!

And yes, you can have two drivers which virtually the same parameters, but one vastly more efficient (larger motor) It will have a lower Q, but when you put them in an IB that doest matter for output.

SPL is very important, you wouldn’t want a driver with a SPL of 10dB would you? End of debate, this is VERY silly.

common guys, and one more thing, lets stop the insults please. (not directed at you lloyd, but that other guy)

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[audiolife 5,000+ posts]

show me a woofer that is 10 db at 1 watt at 1 meter and better yet where does this fall in an actual system? and since when did a larger motor mean its automatically more efficient? spl finals or not some of the same techniques used there can be applied to a loud daily driver. saying what you just said would be like saying xmax is the 1 factor if you had a sealed box with 2 12" woofers the same size with one having an xmax of 1mm and another with 36mm......means nodda its like cereal without the milk or a juggy without any jugs.....

 

[boomanchu]

Remotia=

 

[menikmati 10+ year member]

who cares about what they rate it at, efficiency is an unimportant number. yeah, you dont want a driver with 10 db rated SPL, but who the hell would make a driver like that.