So, difference between a 12 and a 15? Just a tad.

[silenkiller 10+ year member]

So for everyone who's always asking, i.e. Do I want a 12 Inch FI Q or a 15 Inch FI Q??? omgggggg

I did a winisd for both of them and on the same power. If you check the graph, not that this is all inclusive by any means, but they are pretty **** close.

Green is the 15. Red the 12.

They KEY here is that the 15 is in its correct space. Don't go getting a 15 and jamming it into a 2.5 cuft enclosure cuz its "a 15 so it has to be better".

Click to read more...

 

[amartin_72]

A 15 in 4.5ft will kill a 12 in 2.5ft same power. Box space always wins and if its optimum for the subs it will always be louder and lower. Theres no replacement for displacement. Win ISD is not real life. Adjust the sensitivity on the sub paramaters and it messes it all up and since sensitivitys are all measured differently it throws win isd off when comparing two subs. The one rated at higher sensitivity will win most the time even though in real life it could be the opposite.

 

[silenkiller 10+ year member]

A 15 in 4.5ft will kill a 12 in 2.5ft same power. Box space always wins and if its optimum for the subs it will always be louder and lower. Theres no replacement for displacement. Win ISD is not real life. Adjust the sensitivity on the sub paramaters and it messes it all up and since sensitivitys are all measured differently it throws win isd off when comparing two subs. The one rated at higher sensitivity will win most the time even though in real life it could be the opposite.

What I'm getting at is "kill" is kinda taken different from person to person. If being 2-3 db higher at 30-40 hz is killing for someone, it may not be much of a difference for someone else. You know, to not justify someone going crazy and walling off their trunk or some other labor intensive thing. (Not talking about competitions)

 

[azimuth 5,000+ posts]

a 15 has a significant edge in cone area. a 12 and 15 of the same model sub, on the same power, both in well designed/same type enclosure, will noticeably be louder with the 15.

 

[GetLikeMe 10+ year member]

I had my 15" in 3.5 cu@32hz and it ****in bangedddd

 

[CarAudioNewbie9 10+ year member]

Holy shit guys. 2.50 inch boxes for 12s? My Diamond Audio D6 is in a .90 cubic feet box. lol

 

[skmfkr 5,000+ posts]

differencebetween a 12 and a 15 was 4db for me.

 

[skmfkr 5,000+ posts]

difference between a 12 and a 15 was 4db for me.

 

[T3mpest 10+ year member]

wow, learn to use winisd before you attempt to judge a sub with it. Your looking at the gain plot.... That shows frequency responce relative to itself, hence the -1, -3, etc. What actual SPL levels your getting is going to be different. Do that again, click the SPL tab buttom up top then you can see the actual difference in SPL. The frequency response is similar because a 12 needs about half the airspace to sound similar, just won't be as loud.

Despite what 99% of this forum thinks modelling programs do work if you know how to use them. More importantly how to interpert what they see to fit their goals, when taking into account cabin gain. If you can do this, you can get alot closerthan most people who simply use standard recommendations, such as "well XXX brand likes to be tuned at 43.19249hz.. Anyway I'm done ranting lo and i helped lol..