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Ray

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Posts posted by Ray

  10. How do you guys afford it?

    in General Audio - Can't find a category for your question? Ask here.

    Posted

    some of us do this for a living, so coming across deals or build huge customer cars and getting to keep all their old equipment, then i sell it or trade it for 1 nice piece. sure i do pretty well for myself, but i would say alot of it comes from trading. think about this. Add up how much all you stuff is worth then what high end piece you could trade it all for.

    Plus your only 17, hell i know most of the guys around here are at least 20-21, im 26 and alot of these peeps are ol' schoolers. we have been doing this for years. myself coming up on 12 years, meade's got me beat , so dont rush it, take your time.. the time you have right now needs to be used for researching what is good equipment. If you only do 1 thing i ever suggest, its this. read and read and read about car audio, take most of it with a grain of salt but when the time comes for you to buy some equipment you wont buy crap at the very least.

    Ray

  25. comparing cone area & loudness??

    in SPL - SOUND PRESSURE LEVEL

    Posted

    So many times we still hear that doubling the power gets us 3dB and doubling the cone area gets us another 3dB.

    It is a MYTH. 

    It is untrue!

    Electrons flow through our wires to our speakers.

    The electrons are changed to electromagnetic energy.

    The electromagnetic energy works with permanent magnet energy to make a speaker cone move.

    The movement vibrates air and we have sound..

    Doubling the power into the speaker motor may get us 3dB more sound to our ears, but again it may not!

    Just like dumping twice the gasoline and twice the oxygen into our cars motor may not make us go twice as fast.

    It may not, because there are so many variables between the point of the energy being electrons and the energy making it to our ears. There are several variables that may not always have the same value and thus it is impossible to guarantee that a 3dB increase will occur. For instance a loudspeaker motor is not entirely linear, that means if we double the power to it then it may give us 3dB or it may give us less than 3dB depending on things like is the voice coil in the gap at the most efficient spot? Or is the speaker suspension restricting the speaker movement when you add this extra power (it always does!)..?   Or does the acoustic suspension of our box restrict the cone movement (it always does!)..?   

    Along this path from electrons to sound, there is also a lot of our energy that is turned to heat and the heat does not translate to more sound, so there is some loss, quite a bit as a matter of fact.. 

    So, to say doubling the power will always get you 3dB is just a guess at best!

    Defiantly not a law of physics! Definitely not always true.

    But unfortunately, a lot of folks seem to spread this MYTH as if it were fact. 

    Now,  Cone area!

    Cone area is another MYTH, although like power it is very important, it is still just one variable out of many that have to do with getting sound to our ears.

     

    Many say doubling your cone area will get you 3dB.

    This is UNTRUE as well.

     

    It is true that the cone vibrates the air to make sound,  and if we had double the cone area ALSO vibrating the air making the same sound then we might have 3dB more sound!

    But we did more here than to simply change cone area!

    We added cone area that was already playing the same sound!

    So that means that in addition to cone area we ALSO added a motor and the power to drive that motor so it would move the cone the same amount as the first cone!

     

    We cant easily just ADD CONE AREA!

    And if we did by just gluing more cone area to an existing cone then we would have a problem in that the cone area would add mass, thus needing more power to move the extra weight!   So it cant be JUST cone area!

     

    PLUS!

    We can play a 15 inch speaker at 100dB and then play a 10inch speaker at 100dB and we will achieve 3dB more and we can see we DID NOT double the cone area!

     

    Or we can use a 15 inch speaker and have a fat lady sing the same song at the same amplitude and we would still get a 3dB increase, and we have to ask, where is her cone area? And/or where is her power and it is double that used by the 15?  Almost certainly not!

     

    So you see, the POWER MYTH and the CONE AREA MYTH  although based in facts are often misused in the car audio world and are easily proven to be untrue..

     

    But don’t loose all hope!  there is some truth!

    The truth to the physics of sound is actually much simpler!

     

    1. Adding one sound to another sound of the same amplitude (volume) will gain you 3dB.

    2. Adding one sound to another sound of the same amplitude and correlated will gain you 6dB.

    (correlated means exactly the same phase, and likely to occur with the long wavelength of bass notes in our cars)…

     

    How can things be simpler than that?

    Blame these things on the laws of physics of how two or more sounds work together, not

    on cone area or power alone.

    WTF?????????????????

    :-

    Wow, that was horrible.

    It gave me a headache.  Makes no sense at all.

    If you need help deciding on what RF woofers to purchase, I help you out a little...

    Save just a little bit more and get 2 decent 10's or a nice 15" if you have the room..  

    What kind of car?

    What is the budget?

    Do you all ready have some equipment? amp, wire etc????

    Are you looking for the loudest setup within this budget or more towards it sounding good on a certain type of music, ie: rock?

    What type of music do you listen to?

    Ok go with that for now.

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