your question isnt specific enough.
stock car audio speakers vary.
and when you start talking about aftermarket car audio speakers.. that is a totally different category that varies.
pro audio speakers vary only two three ways:
1. they are ment to get loud with a wide dispersion pattern
2. they are not ment to get loud, but keep their dispersion pattern.. and generally are 'known' to be failing in the DJ industry, but would be used in the home.
usually when they dont get loud, they sound a bit better.
3. they are ment to get loud, sound better than their competitors, and have a varying dispersion pattern (not necessarily much, but enough to be annoying when you want more)
just like some lcd televisions have a wide or narrow viewing angle.. pro audio speakers are ment to have the same wide listening angle.
to that degree.. they are also ment to project their output towards the other end of the room.
dont think of it much like a crt or lcd television compared to a projector.
because pro audio speakers dont meet the comparison of being a projector without some calibration of reverb.
pro audio speakers arent ment to sound good up close either.
sometimes there are gaps and nulls in the frequency response (and overall output) to blend in with the walls of the establishment they are being played inside of.
if you have ever heard a DJ at a bar..
the speakers sound better when you are about 30ft away from the speaker.
instead of calibrating the reverb.. the reverb is taken out of the speakers.
speakers that sound good up close wouldnt sound as good 30ft away.. these speakers need reverb to sound good up close and far away.
muddy up close, clear far away.
clear up close, muddy far away.
with reverb.. it is clear up close (if the speakers are clear) and also clear far away.
car audio speakers can do quite a bit.
whatever has been released in the last 10 years might prove to be different.
the speaker needs to sound good from about 5ft away.
any speaker can sound really good up close and be calibrated/tweaked to sound good further away too.
the stock speakers are trash generally.
they are low power handling and their output isnt clear.
however, sometimes their slew rate is higher.. meaning more sound appears to pour out from the speaker.
this generally doesnt happen unless the signal to noise ratio is lower.
you can of course go to the store and find some speakers with a higher slew rate, with a higher signal to noise ratio.
these speakers can prove to be questionable when you really push them with anything more than wattage.
sometimes wattage alone is enough to ruin the good sound.
other times.. using an equalizer or reverb can kill the fidelity.
anyways.. some people consider slew rate differently.
slew is hearing the instructions and reacting.
higher slew = higher attention and focus (confused with higher sensitivity)
simply because the speaker is sensitive.. that doesnt mean it can carry everything.
it is like a person who has a list and says 'i need this, this, this, and this'
they can only carry two things.
simply SEEING that they need to carry four things = high sensitivity.
being able to see that they need to carry four things AND actually being able to carry all four things = high slew rate
pro audio speakers have pathetic slew rate.
many car audio speakers hae pathetic slew rate too.
going aftermarket is supposed to help.
sometimes you will find aftermarket car audio speakers that have a worse slew rate than what they are replacing.
sometimes pro audio speakers can have a higher slew rate.. because that is all pro audio speakers have to keep the category of quality seperate from one speaker to the other.
all speakers have different frequency responses.
you would prove to be happier with car audio speakers before pro audio speakers when talking about the same size.
since you arent talking about midranges, but subwoofers..
things can prove to be the same, but there are dozens of pro audio subwoofers that sound better than the majority of car audio subwoofers.
the pro audio subwoofers are going to require loads of wattage, and it isnt necessary.
a pro audio subwoofer is ment to sound good in a wide open space.. and it wont sound as good inside a small living room.
if you put a home subwoofer up in a DJ setup.. it can be embarassing like an infinity car audio subwoofer.
it will try to play everything and squeel.
the pro audio subwoofer will not try to play everything, and will be muddy.
there is only one definitive way to see this.
imagine the entire frequency range works at a specific frequency.
sometimes the frequency is high like 100hz (the infinity subwoofers)
sometimes the frequency is low like 10hz (the kicker or mtx subwoofers)
the only problem you might run into with this example is when the lower frequency 'muddy' sounding speakers dont actually sound muddy because their slew rate is high.
same can be said with the higher frequency speakers.. they might be working at that frequency, but they dont output all of the audio details.
there is two different resonant frequencies in the specifications of a subwoofer.
one is the spider and rubber/foam surround.. what frequency does it 'enjoy' moving back and forth.
the other is the voice coil.. what frequency does it 'enjoy' or is 'forced to' move back and forth at.
usually the voice coil frequency is not specifically stated.
you might be able to figure out an equation from some of the other numbers in the list of theile small parameters.
as i said, the number isnt listed as a specific hz.
as speakers evolve..
there will be more than one resonant frequency that the voice coil 'enjoys' or is 'forced to' move at.
i suppose the spider and surround can also see more than one resonant frequency, but it isnt absolutely necessary in most cases.
to say again..
when a speaker sounds low and appears to be moving lots of air with details.. that is a lower resonant frequency of the voice coil.
when a speaker sounds high and appears to be trying to move nothing but details and no air.. that is a higher resonant frequency of the voice coil.
there is a parameter called 'FS' that claims to be the resonant frequency.
when you put it in a box and start to tune it.. there is another parameter called 'F3' that also claims to be the frequency.
there is something very important here that could earn you a perfect build.. or some money if you learn it and do it for other people.
there is a high resonant frequency that is the energy.
there is another resonant frequency that is of null, or simply put, dull and nothing (the opposite of energy).
you have to match the tune of the high and low with the tune of the box to get all three working together for a complete build that appears to be 'working its butt off' throughout all of the frequency range.
otherwise you get lots of peaks and dips... meaning, those peaks and dips are severely higher.
learn this and learn what your speakers are really worth.. !
sometimes they can be stretched to do it all with some dull points inbetween (to use an equalizer to fix it)
they simply cannot be stretched and must have their frequency response shortened.
other times still..
they can be stretched across the frequency range, but cannot handle being equalized (very stupid and unfortunate, but true).
to be fully honest..
the third instance where it was stretched and cannot handle much equalization..
it proves to be true, but they can still handle a small bit of equalization.
could be cut that kills it.. could be boost that kills it.
could be the way the whole thing is setup.. meaning the speaker can handle more boost in this area than in a different frequency area.
and that means you might have built the box backwards.
this isnt always noticeable if you keep the wattage down to keep the heat on the voice coil down.
much more noticeable if you are gambling with things at the thermal limit.
being 25% away from the thermal limit.. using that equalizer could bring you up to the limit quicker than you had hoped.
usually because the speaker isnt playing loud enough, or because the amplifier sounds better at higher volume levels (more current / more transients / both)