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yehi just got the infinities 6000cs installed with a 201s RF amp

and it sounds kick ***, i have 2 10" subs in the trunk, combined with the crystall highs that the infinities can make, its sounds awesome

but it does lack in the punchy midbass a little bit
i keep trying to compare speakers, and i listened to stock speakers in a merceses c230 coupe last week, and the 6.5" mids have incredable bass. i couldnt believe how loud and punchy it was.

i want mine like that
i wonder if it is the car's engenerring that made that sound or the speaker
or what could it be?

 
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the speaker and teh install... if you want midbass like that youd need to add new midbass drivers

 
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what about the install is really different, aside from the fact that those german cars are rock solid

it pops your ears when u shut the door, i love it

 
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that right there does a world for low end response. separation of the front and rear wave, eh fact that the door is COMPLETELY sealed from teh other side of the speaker... also, the benz is sound deadened so much better, so you get no cancellation from resonance

 
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what do u mean, the front and rear wave?

 
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when a speaker moves, it goes two directions, back, and forward. just as the forward motion pushes a wave forward out from the cone, pushing back produces a "backwave" that comes from teh back of the speaker.

this wave is 180 degrees out of phase with the front wave.

ever try playing a subwoofer freeair? notice it didnt make too much noise? the back wave is cancelling out the front wave, no noise is being made!

so we can greatly increase the low frequency extension of our front speakers, usually in the midbass region, but restricting the backwave, such as matting the door sealed from from the cabin, or using foam cups behind the speakers.

 
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as far as resonance cancellations, this is why we deaden the door panel, both the frame and the outer skin. waves can bounce off the door skin directly behind the speaker and reflect back, causing cone interferrance or direct in cabin cancellation.

some people believe the use of aluminum backed deadeners such as dynamat extreme actually worsen the problem rather than help, as the wave can bounce off the aluminum backing and bypass the door. I happen to believe this myself, but thats all it is. a belief.

also simple kinetics, inertia, the moving mass of the cone can vibrate the doorpanel itself, the metal frame the speaker is attatched to. so by mass loading that panel with as much weight as possible, we can increase the amount of force we have to put into the panel to get it to overcome inertia and resonate.

just a little more detail on what lud was saying....

 
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ahh gotcha, but this leads me to another question,

why is exact box size so imporant?
is it that the closer a box is built to specs, the more backwaves it blocks/deflects

and...say if a box was built for the midrange 6.5" woofer in the door panel, would that give it a significant increase in bass response? or clean up the sound entirly?

 
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box size is so important due to the fact that different box sizes apply different amounts of resistance on the motion of teh speaker...

bigger box, takes less to move the cone, smaller box, takes more to move the cone

and as to the mid in the door, depends on teh mid, some work better free air, and thats why im building a box for an 8 in my door as oposed to just running it free air

 
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right, each speaker is rated for a different "Q" value.

Q refers to suspension of some form. qes refers to electrical suspension on the woofer, qms is mechanical Q, Qtc is total Q of just the driver itself.

perhaps youve played around with winISD (www.linearteam.org) a box building program, youll see QTC ratings. QTC is the suspension on a woofer as a result of ALL factors, including box. if you increase size, youll see QTC drop, smaller box and QTC will increase.

a Qtc of .707 (root 2) means that the suspension of the driver perfectly represents reality and will mimic whatever waveform you feed it. in reality this isnt neccesarily true, but it pretty much guarantees an anechoic flat frequency response.

in practice, many drivers perform better with a Qtc of above or below .707. as a general rule, a woofer will become warmer and more accurate with a qtc of below .707, but transient response (ability to hit fast beats) suffers. again, this is only a general rule.

what is ALWAYS true, however, is that the volume of a box, whether its for bass, midbass, midrange, ported, sealed, bandpass, or dual chambered horn loaded isobaric transmission line whatever box, it affects the frequency response.

a ported box tuned to X frequency can help low frequency extension over sealed. tuned to Y will decrease it. increaseing the volume will decrease boomyness. or increase it.

thats why we like to model up speaker performance using a program like blaubox or winISD pro to see what a certain box will give us out of the car, so we can get an idea of what performance will be like IN the car

 
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hummm....sounds interesting
i gotta learn the technical aspect of this stuff

 
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if you just really get into the audio hobby, the stuff you just learn over time.
me and whiterabbit spend a lot of our time in the audio world.

i mod this forum, whiterabbit is the owner of the www.caraudioforum.com chat room where me and him just kinda hang out in when were online...

also you could always read all teh pages i linked in the sticky post up top, and theres a few books out there i could reccomend if youre REALLY interested

 
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if i had more spare time i would read them...but university is enough reading for me

 
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I have fanatic Xs on my front, the highs are extremely high and the lows...well my doors can't handle the lows so you'll need foam baffles or dynamat on our doors if u put in the RFs. And no, rockfords don't suck, I have only 1 ten inch RF woofer in my trunk and it'll easily own 2 subs...the box is very very important.