Hypothetical: Many small subs or two bigger?

[wevie 10+ year member]

A lot of times I hear someone ask about a recommendation for a single 15" sub or similar. Many times a response is given to use two 12" subs instead. More cone area, etc.

Now, given that, at what point do you see diminishing returns?

Hypothetical situation: Not considering space requirements - (2) 15" subs, (4) 12" subs, (8) 10" subs.

I suppose you could add to the list (1) 18" or (?) 8". Are their viable 8" subs?

Is there a point where dropping size in order to increase the number of subs, thus increasing total cone area, is not a good idea?

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[phemps 10+ year member]

there are sooo many variables. but cone area is always good. more air movement and heat dissapation over multiple drivers compared to one

 

[95Prober 10+ year member]

Im curious about this as well, BUT with set air space added into the equation.

Do I sacrifice air space for more subs to get more cone area, since some people think more subs the better OR less subs or a single larger sub like an 18" that has the same amount of air space to work with

 

[skmfkr 5,000+ posts]

15s is a better value giving you more cone area than 2 10s and buying only one woofer compared to 2 is cheaper.

 

[wevie 10+ year member]

15s is a better value giving you 2x the cone area of 2 10s and buying only one woofer compared to 2 is cheaper.

Let's not add variables (cost) into the equation.

Cone space vs. air space. Good thought. Hmmm....

 

[mobeious 10+ year member]

well look at it this way 4 12's is 452.16sq of cone, as where 2 18's is 508sq of cone

so if u take 4 decent 12's and put it against 2 decent 18's u have to take power into consideration... those 2 18's can handle 1000watts each daily... the 12's can also handle 1000watts each daily... so essentialy u can run 4000watt to the 12's and 2000 watts to the 18's the extra 2000watts will make up that 56sq of cone difference and then some... but if ur talkin same power to same power the 18's would prolly move more air... it all depends on the moving mass of the sub

 

[MakeshiftAudio 10+ year member]

4"VCs FTW. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif More than your wimpy 1kW 18"s.

 

[JimJ 5,000+ posts]

so if u take 4 decent 12's and put it against 2 decent 18's u have to take power into consideration... those 2 18's can handle 1000watts each daily... the 12's can also handle 1000watts each daily... so essentialy u can run 4000watt to the 12's and 2000 watts to the 18's the extra 2000watts will make up that 56sq of cone difference and then some...

With the effects of power compression, I wouldn't be so sure.

 

[mobeious 10+ year member]

With the effects of power compression, I wouldn't be so sure.

im talking loudness not airmovment

 

[wevie 10+ year member]

well look at it this way 4 12's is 452.16sq of cone, as where 2 18's is 508sq of cone

so if u take 4 decent 12's and put it against 2 decent 18's u have to take power into consideration... those 2 18's can handle 1000watts each daily... the 12's can also handle 1000watts each daily... so essentialy u can run 4000watt to the 12's and 2000 watts to the 18's the extra 2000watts will make up that 56sq of cone difference and then some... but if ur talkin same power to same power the 18's would prolly move more air... it all depends on the moving mass of the sub

Ah yes, but... you jumped a size. (1) 18, (2) 15's, (4) 12's

You are comparing (4) 12's to (2) 18's.

 

[FurbiesAndBeans 10+ year member]

Ah yes, but... you jumped a size. (1) 18, (2) 15's, (4) 12's You are comparing (4) 12's to (2) 18's.

He's comparing similar cone areas.

More woofers mean more motor power also btw.

 

[T3mpest 10+ year member]

well look at it this way 4 12's is 452.16sq of cone, as where 2 18's is 508sq of cone

so if u take 4 decent 12's and put it against 2 decent 18's u have to take power into consideration... those 2 18's can handle 1000watts each daily... the 12's can also handle 1000watts each daily... so essentialy u can run 4000watt to the 12's and 2000 watts to the 18's the extra 2000watts will make up that 56sq of cone difference and then some... but if ur talkin same power to same power the 18's would prolly move more air... it all depends on the moving mass of the sub

Yeah your putting more power on them but that's about it. Each sub takes x amount of watts to move a given distance and move air, plus excite the port. You need more power since each sub has less cone area. In the end it's all about how far much displacement you can get near tuning. BL and powerhandling come into play, but displacement does too. As long as the 18's can make move just as much off of 1000 each as the 12's do on 1000 each your 18's still hold a slight advantage. After all 2

12's moving 7mm is still less displacement than 1 18 moving 7mm. The fact that you used 2000 watts on 2 smaller subs is basically just being ineffecient. Power doesn't matter, it's what the power actually does that makes sound. Especially since all subs are 1000 watts so power compression should be similar.

 

[mobeious 10+ year member]

Yeah your putting more power on them but that's about it. Each sub takes x amount of watts to move a given distance and move air, plus excite the port. You need more power since each sub has less cone area. In the end it's all about how far much displacement you can get near tuning. BL and powerhandling come into play, but displacement does too. As long as the 18's can make move just as much off of 1000 each as the 12's do on 1000 each your 18's still hold a slight advantage. After all 2 12's moving 7mm is still less displacement than 1 18 moving 7mm. The fact that you used 2000 watts on 2 smaller subs is basically just being ineffecient. Power doesn't matter, it's what the power actually does that makes sound. Especially since all subs are 1000 watts so power compression should be similar.

well i guess i didnt explain enough i was talking if it was say 4 Fi q 12's vs 2 FI Q 18's same sub so same excursion

 

[terra 5,000+ posts]

im talking loudness not airmovment

Relating to power compression how..?

 

[spencer321 10+ year member]

well look at it this way 4 12's is 452.16sq of cone, as where 2 18's is 508sq of cone

that is NOT how you calculate cone area... your values are incorrect because your using the entire cone, surround to surround as your piston and your piston is only a portion of your surround depending on the company 1/2 to 1/3 of the surround counts.

I wish people would learn this