i'm just going to go with one sub for my car, going to get the 12" Fi Q. i'm going for SQL and was wondering, would a 15 inch be a better choice than a 12 since i am just doing one sub? or should i just stick with one 12? the 15 is only $20 more than the 12 so if a 15 would be a better choice it wouldnt be much more to go with it. i would be playing rock mainly on this set up, some rap from time to time. the sub will be going into a ported box tuned to 30 Hz.
how much max height would i need to fit a 15 inch sub using 3/4" mdf? 16.5 or 17 inches maybe? 15 will be louder, but would a 12 have better SQ or would the SQ with the 12 or 15 be about the same. i'm looking for the optimum choice.
the only real difference with a 12 and a 15 is that a 15 will hit lower notes. i think the reason bigger subs get looked down on is the box. you need to put alot of care into your boxes. small things make a big difference. if you make a nice box then go with the 15.
well guess what just cuz 15 is larger doesnt mean its going to hit the lower notes better or get louder ... please know what ur talking about before u give people advice..
the 15 inch q's ability to hit a wide variety of notes is its trademark along with above average sq ...
in a sealed box it produces a very tight bass with the ability to hit the low notes .. but in comparison the 12 and the 15 arent much different side by side .. and yes i have owned a 15q ..
great sub either choice would be awesome and would excel in exactly what u want to do...
not saying the q is going to be like this but with my arsenals, the 15 was slopplier than the 12 when it came to tight bass like rock. not sure if the q is the same but if it is and you listen to mainly rock I would go with the 12
anyone agree that the 12 Q is a better choice for rock than the 15 Q?? also i plan to put this in a ported box tuned to 30 Hz, would the 15 sound better in a sealed box? or would a low tuned ported box be just as good?
I have never had a problem that was noticable by ear of a 15" subwoofers not being able to respond as fast as a 12".
That is a subwoofer Myth:
"One of the biggest myths about woofers is that 8's and 10's are "tighter" and "cleaner" than 15's or 18's. Nothing is further from the truth. What tends to happen is that the smaller drivers have lower Q's because manufactures tend to put large cones on smaller motors to increase SPL and sensitivity but not BL product. Well unless the motor can compensate for the extra mass it has to push, then the Qts will not be the same as the smaller drivers and ultimately the driver may not be suited for the same kinds of alignments and could ring too much and compromise the perceived sound quality. Having said that, high Qts drivers are not any less "tight" or "musical" than well dampened drivers, it's just they require larger boxes and less internal pressure to prevent ringing. Ultimately there becomes a point where a driver really should be used in an infinite baffle where its actual Qts and Fs becomes the system Qtc and Fc. As enclosure volume decreases, Qtc increases and it will take a driver with a low Qts to make for an average Q system. So in conclusion, the only reason to use a smaller bass driver is for space, weight and potentially power considerations, but likewise, it is inappropriate to try and fit a larger driver into a space smaller than it is ideal for." - Audiopulse/TC Sounds
sounds good ill go with the 15 Q :D another question now. i just drew up a rough idea of a ported box and once the driver is mounted the back of it will only be 3/4" from the port wall. is this a problem? will it be ok as is, should it be a certain distance from the inside port wall? if i needed more room could i just do a double baffle or redesign the box? also would a double baffle be a good idea when making a box for a 15" sub?
ok i got a box thought up now, should work. it will be 3.43 ft^3 after sub disp. width is 33", height is 17" and depth is 17.25". port will be 15.5" X 2.5" and its physical length will be 26.5" for tuning of 30Hz. i will draw this up later today and post a pic of it. i will need some help and advice on bracing though.
i got a 15 inch mag in my car. the bass sounds awesome on heavy metal with fast kick drums. it also sounds awesome with trance and techno with fast beat. if the q is anything like the mag then the 15 will do good.
i've also heard that 12's are better for rock than a 15. 15's are more for deeper bass, which would be nice but not all of what i'm looking for. i'm still not sure yet if i am going to go 15" or 12", but i may just go with the 12 since the box will be smaller in size. to hold a 15 the box is going to have to be a little taller than i really want it to be. unless i find a way to make a slanted box that is ported that will fit in my car so it can be shorter in overall height i may just go with the 12. thanx for all the input guys it's very much appreciated.
Polo.. 
