familiar with the saying "theres no replacement for displacement" tru 4 subs as well?

[kush-divinity 10+ year member]

If you listen to music, 4x12 > 1x15.

If you listen to test notes, maybe = or 15 better.

Who listens to test notes?

 

[spencer321 10+ year member]

Not really. It forces a considerably more dense air charge into a combuston chamber. When burned it creates way more energy. It doesn't spin the shit out of your engine. It operates mainly with the same range it does naturally asperated. Because it has so much more power, when wide open, it flys through the rpm band a lot faster.
Most engines actually lose power past a certain RPM range.

that was a joke man, im way more familiar with engines than i am car audio lol, and the air is not necessarily denser, it is however pressurized but pressure increasing is a thermal reaction causing the air to heat up so it is less dense but there is more volume, 14.7psi would be twice as much volume in fact (1 bar) the only way to eliminate the heating affect is with an intercooler, and the only way your air charge is going to be more dense is with either nitrous or a water to air intercooler, something with greater than 100% efficiency

 

[spencer321 10+ year member]

Good output comes from efficiently coupling the speaker to the enclosure and the speaker/enclosure to the interior of the vehicle. Sometimes that takes power and sometimes that takes cone area but it always takes a well planned and designed enclosure.
Speaker displacement is a very small factor in the grand scheme of things. If you take an 18" XXX and set it in the trunk and put 10k watts on it, you're not going to get any bass. Go ahead and add 5 more and 50k more watts and guess what? You will just hear them bouncing around in the trunk not putting out any bass. Even though they're displacing a ton of air, they're not efficiently coupled to the vehicle and so you get no output.

i don't mean for this to come across sarcastic but, the question at hand is under the assumption that i know how to build a box and anchor it to the chassis (which i do) this is one of those "all things equal and properly done" scenerios where the only variable is cone area, not box or the ability to install it.

 

[mrogowski 5,000+ posts]

Quantities of smaller drivers will win overall. You are spreading the power across them equally which will result in lower overall IM distortion because they will not have to exert themselves like a single driver would.

And since the addition of power to a driver is not linear, you simply cannot expect increased output from a single driver verses an array.

m

 

[tez4life Premium Member]

Interesting discussion,

I recently went from (4) 12s sealed with 1200RMS to (1) 15 ported off 800 to 900w and honestly, the single 15 was louder. And I mean on music, I dont listen to tones, this was a daily driver.

However, I felt the 12s had a bit more to give, they seem to do everything, note wise, well, where as the 15 had its peaks and valleys. But, this was not a fair compariasion, the 12s (AA Assassins) were SQ with low rms's (350w) where the 15 (RL-p) had a pretty normal RMS (1000w I believe)

Im kind of in the same dilemia as the OP, I want low end but output too. Must sound good at low volumes as well as high volumes too. Im leaning toward a pair of 18s sealed to give me what I desire.

 

[DDeitz 10+ year member]

single subs are louder, that is why the loudest set ups in the world are jl dub 7's off 1000/1's

 

[mrogowski 5,000+ posts]

single subs are louder, that is why the loudest set ups in the world are jl dub 7's off 1000/1's

Hey! Why don't you set the record straight and show us how those eight IXL's are coming?!

 

[DDeitz 10+ year member]

Hey! Why don't you set the record straight and show us how those eight IXL's are coming?!

dont get me started !! been calling the repair shop quite a bit about the amp apparently it was supposed to be finished being looked at today.....i dont want to have to send it out but i may have to cause they are taking forever

 

[helotaxi 5,000+ posts]

that was a joke man, im way more familiar with engines than i am car audio lol, and the air is not necessarily denser, it is however pressurized but pressure increasing is a thermal reaction causing the air to heat up so it is less dense but there is more volume, 14.7psi would be twice as much volume in fact (1 bar) the only way to eliminate the heating affect is with an intercooler, and the only way your air charge is going to be more dense is with either nitrous or a water to air intercooler, something with greater than 100% efficiency

If you know more about engines than car audio, based on the above you know squat about car audio, maybe less than squat. By compressing air, the temp goes up but density goes up as well. That's basic chemistry. The temp increase causes a slight drop in potential power gain that can be made up by cooling the denser charge using an intercooler, but the intercooler has no effect on density as long as volume is kept constant. The main reason for going with an intercooler is to allow more boost without detonation. Nothing to do with density. Nitrous cools the charge but also decomposes to provide more oxygen, increase combustion chamber pressure and allows more fuel to be burned.

To answer the original question Cone area is a key in efficiency, but not potential peak output. If you have limited amount of power, more cone area has the potential to get louder. If you have unlimited power, you can do amazing things with single drivers but if you can only run a small amount of power several drivers will make better use of it. Also no need to run a lot of low power drivers. You don't need to run RMS to subs.

 

[spencer321 10+ year member]

If you know more about engines than car audio, based on the above you know squat about car audio, maybe less than squat. By compressing air, the temp goes up but density goes up as well. That's basic chemistry. The temp increase causes a slight drop in potential power gain that can be made up by cooling the denser charge using an intercooler, but the intercooler has no effect on density as long as volume is kept constant. The main reason for going with an intercooler is to allow more boost without detonation. Nothing to do with density. Nitrous cools the charge but also decomposes to provide more oxygen, increase combustion chamber pressure and allows more fuel to be burned..

insults not required, and yes i was wrong about the density of compressed air, density is mass over volume so compressed air will have greater density, however the intercooler does directly influence the density of the air as it cools the charge of air, i already went over this, density is mass over volume so if the volume is constant and the mass changes then denisty changes, temperature directly effects the mass of air, why do you think hot air rises(like in a hot air baloon) and cold cold air falls(like when you open the fridge) so yes, the intercooler does directly effect the density of the air going into the engine even with a constant volume. nitrous does break down into 1 part oxygen and greatly increases the % of oxygen in the combustion process as compared to ambient air, but the other part of that breakdown is nitrogen which is super cool and does increase the density by lower the charge temp. and as far as detonation is concerned yes an intercooler helps prevent detonation but it does so by cooler the charge, nitrous does the same thing, thats why alot of "nitrous" motors have such high compression because the intake charge is supercooled coupled with C12 or C16 and you have virtually eliminated combustion.

and if you disagree thats fine, i didn't start this thread to argue thermodynamics and i don't intend to address the subject further. not trying to be a dick but its not why i started the thread. and i'm getting alot of mixed answers on this cone area problem

 

[spencer321 10+ year member]

Interesting discussion,
I recently went from (4) 12s sealed with 1200RMS to (1) 15 ported off 800 to 900w and honestly, the single 15 was louder. And I mean on music, I dont listen to tones, this was a daily driver.

However, I felt the 12s had a bit more to give, they seem to do everything, note wise, well, where as the 15 had its peaks and valleys. But, this was not a fair compariasion, the 12s (AA Assassins) were SQ with low rms's (350w) where the 15 (RL-p) had a pretty normal RMS (1000w I believe)

Im kind of in the same dilemia as the OP, I want low end but output too. Must sound good at low volumes as well as high volumes too. Im leaning toward a pair of 18s sealed to give me what I desire.

and my theory gets completely disproved lol how does the low end frequency response compare between the 12's and the single 15? one would assume because the 12's have the ability to move more air they would be more pronounced at lower frequencys but i could be wrong

 

[helotaxi 5,000+ posts]

insults not required, and yes i was wrong about the density of compressed air, density is mass over volume so compressed air will have greater density, however the intercooler does directly influence the density of the air as it cools the charge of air, i already went over this, density is mass over volume so if the volume is constant and the mass changes then denisty changes, temperature directly effects the mass of air, why do you think hot air rises(like in a hot air baloon) and cold cold air falls(like when you open the fridge) so yes, the intercooler does directly effect the density of the air going into the engine even with a constant volume. nitrous does break down into 1 part oxygen and greatly increases the % of oxygen in the combustion process as compared to ambient air, but the other part of that breakdown is nitrogen which is super cool and does increase the density by lower the charge temp. and as far as detonation is concerned yes an intercooler helps prevent detonation but it does so by cooler the charge, nitrous does the same thing, thats why alot of "nitrous" motors have such high compression because the intake charge is supercooled coupled with C12 or C16 and you have virtually eliminated combustion.

Dude you really need to study thermo, but start with basic chemistry and physics. The only factor in density of a gas is mass and volume. Temperature is independent. If you take a given volume of air and compress it, the temperature increases but the density increases as well. Basics. The temperature increases because the pressure increases. Hot air rises through the air column because it is allowed to expand. The expansion, not the temp is what causes the decrease in density. The expansion is caused by the heat, but heating does not cause a decrease in density if the volume and mass is fixed. The only way to increase mass is to add more molecules. Cooling does not increase the molecular count. It reduces pressure, that's it.

Nitrous doesn't increase density, but it does increase the pressure in the fixed volume when the gas breaks down since every 2 molecules of NO2 break down to two molecules of O2 and a molecule of N2. The cooling effect has nothing to do with the chemicals used and everything to do with the expansion of the gas as it is released from the cylinder.

The reason cooling reduces detonation is that gasoline has a combustion temp. Reach that temp and the fuel/air mixture ignites regardless of the presence of a spark. Starting with a lower latent heat gives you more leeway for compression heating before compression combustion (dieseling) occurs.

You've gotten a bunch of answers in this thread from people without a clue and a few from people that know something.

 

[spencer321 10+ year member]

Dude you really need to study thermo, but start with basic chemistry and physics. The only factor in density of a gas is mass and volume. Temperature is independent. If you take a given volume of air and compress it, the temperature increases but the density increases as well. Basics. The temperature increases because the pressure increases. Hot air rises through the air column because it is allowed to expand. The expansion, not the temp is what causes the decrease in density. The expansion is caused by the heat, but heating does not cause a decrease in density if the volume and mass is fixed. The only way to increase mass is to add more molecules. Cooling does not increase the molecular count. It reduces pressure, that's it.
Nitrous doesn't increase density, but it does increase the pressure in the fixed volume when the gas breaks down since every 2 molecules of NO2 break down to two molecules of O2 and a molecule of N2. The cooling effect has nothing to do with the chemicals used and everything to do with the expansion of the gas as it is released from the cylinder.

The reason cooling reduces detonation is that gasoline has a combustion temp. Reach that temp and the fuel/air mixture ignites regardless of the presence of a spark. Starting with a lower latent heat gives you more leeway for compression heating before compression combustion (dieseling) occurs.

You've gotten a bunch of answers in this thread from people without a clue and a few from people that know something.

i appreciate the chemistry lesson. and i have no idea who has a clue and who doesn't but i do know you haven't contributed anything to the thread about the topic so if your one of the ones that has a clue which i suspect you are, can i get your opinion on the topic?

 

[Anonymous 10+ year member]

Cone area does not mean everything. You can have 10 15's but if they are sealed and crammed into a vehicle without the right airspace or power you really just wasted alot of money. And with that many subs you also run into cancellation. I have went from 4 12's to 4 15's to 2 15's. The 2 15's were louder on the same power in the same vehicle than the 4 12's and 4 15's. Moral of the story cone area is not the solution. Install is.

 

[spencer321 10+ year member]

Cone area does not mean everything. You can have 10 15's but if they are sealed and crammed into a vehicle without the right airspace or power you really just wasted alot of money. And with that many subs you also run into cancellation. I have went from 4 12's to 4 15's to 2 15's. The 2 15's were louder on the same power in the same vehicle than the 4 12's and 4 15's. Moral of the story cone area is not the solution. Install is.

i don't mean for this to come across sarcastic but, the question at hand is under the assumption that i know how to build a box and anchor it to the chassis (which i do) this is one of those "all things equal and properly done" scenerios where the only variable is cone area, not box or the ability to install it.

you need to read before you post, i understand that. Im saying if your subs have the necessary air space, and are install properly. your adding your own variable that im not asking about because its assumed already.