very simple question

[cotjones 10+ year member]

i'm in school pursuing m.s. in ee; i fully understand what your doing and how to achieve it.
however, it truly isn't worth the insane amount of work you're going to need to put into it to do it correctly. how many crossover's have you designed? i hope you have alot of experience designing them; you'll need it.

it would just be 1000000x times easier to have a nice, solid sub stage with a good component set to complement the midbass. make some kickpanels for midbass; it will save you so much trouble, when chances are your real world results won't equal whats on paper.

i'll design systems that will function **** near perfect(engineers don't care about exact; we leave that to the mathematicians), but in the real world, it won't be near as efficient as on paper. too many real world variables.

i won't argue with yout o stop you, i'm just offering my input and educated opinion. however, it's ultimately your decision; do as you wish.

i know what ur saying but i'm just the kind of person that i want somethin truly uniquly better than the rest no matter the cost... besides that the frequancy cutoff doesn't have to be exact to get extremely good sound i've already got the ability to do that, then all i'll have to do is match the outpuls leves witch woun't be too amazingly hard either with an acurate spectrum anaylizer since there are 2 amps controlled independantly

 

[Imshirazy 10+ year member]

Tell you what, I'll help you out. I'll find out the formulas myself if I have to, just PM me if I don't type back tomorrow because then I forgot

Simply, even though everyone makes it sound hard, it's truly not...

The biggest issue is just volume, so you have to run in and out of your car to hear/adjust

then when you're settled for all you know a different song is going to sound way off etc.

It will definitely be unique, I will give you that, and the quality from the subs although will be very hard, I still think it will sound better as long as you get the cut off for the 13 at maybe 42 and the cutoff for the 10s at 48 if possible.

Just do this

Angle your 10s either to the sides of your car, or toward your backseats

aim the 13 at the end of the trunk

from there try to get the crossover situation working

then from there mess with the volume

give it about an hour or so and you'll have a fairly good setup that will sound better than a pair of the same size subs as long as you have a basic concept of what to do, might take a bit over an hour actually...

But if you want the real precise or close to perfect/really good setup then yes, it will take quite the while.

A good car tuning should take about 2 weeks for the full surround of the car.

Luckily enough, alpine and pioneer now have technologies integrated into their head units whereas by use of a microphone, this can all be done in 20 minutes. and even 20 minutes is a long time, and it's a computer doing the job, let alone a person.

i suggest also, that since you want the 13 to play the real lows, either use a very large sealed box or a ported tune to 30 or so. I definitely highly recommend sealed for the 10s.

Can you take a picture of the trunk and post it here so I can see what you plan to do?

or the overall space you plan to use, whether or not you will use fiberglass/mdf/plexi etc

 

[Imshirazy 10+ year member]

never mind I just say the box on the picture gallery

I'm not so sure how healthy a box like that is for the subs or sound reproduction :/

 

[KoolieTheKoala 10+ year member]

so let me get this straight, two speakers playing different frequencys are going to cancel eachother out?

that makes sense!

u smell.

 

[cotjones 10+ year member]

so let me get this straight, two speakers playing different frequencys are going to cancel eachother out?
that makes sense!

u smell.

that makes no sence y would different frequencies cancell?

 

[alteraudiousa 10+ year member]

they way he has it he will have a smaller amt of cancellation that what he had in his previous picture in his absolutely flamed thread! You will have cancellation towards the 45hz range where the two subs will be effectively playing the same frequencies there. If you don't remember almost all the Alpine demo cars use multi subs in their cars, ie. two of the Civics had 15s, 12, and 10s. You will need something to customize the crossover slopes and still have a seperation in frequencies. If you want it to be at 45hz for the 15, than for the 10s have it at 60 or 80hz. Also work with the crossover slopes to be 12db or greater for both. You may also need to play with the phase but thats something totally different. With the proper equipment and installation having multi-sized subs in a car will work, it just takes a lot of work. Also look at some HT setups, I had a martin logan setup using one 15, two 12s and four 8s just for the sub frequencies and some midbass.

 

[DFW40 10+ year member]

You can make this work I'm sure but like someone else said it takes a ton or work with possibly marginal results. You take out the 13.5 and add two more tens and give each 3(10's) a 1000/1 it will kill whatever you are trying to do. If you want the tens to go a little deeper then make you box bigger and add some polifill and give you subs a boost on the slash amps at around 35hz.

 

[cotjones 10+ year member]

they way he has it he will have a smaller amt of cancellation that what he had in his previous picture in his absolutely flamed thread! You will have cancellation towards the 45hz range where the two subs will be effectively playing the same frequencies there. If you don't remember almost all the Alpine demo cars use multi subs in their cars, ie. two of the Civics had 15s, 12, and 10s. You will need something to customize the crossover slopes and still have a seperation in frequencies. If you want it to be at 45hz for the 15, than for the 10s have it at 60 or 80hz. Also work with the crossover slopes to be 12db or greater for both. You may also need to play with the phase but thats something totally different. With the proper equipment and installation having multi-sized subs in a car will work, it just takes a lot of work. Also look at some HT setups, I had a martin logan setup using one 15, two 12s and four 8s just for the sub frequencies and some midbass.

its the same setup its worded different the only difference is that in the other thread i had 4 10's i kept saying that i wanted to run the different size subs at different frequencies... no one wanted to hear that they are more interested in flameing then helping... but with jl amps i don't think i will have to worry about phase cancellation because of the ability to reverse polarity...(if i understand that concept correctly)... so the problem is that one of the chains will be over powering the other at specific frequencies? so i have another question... is that bad? they are in separate airspaces so it won't compromise the quality of either sub to play at a lesser volume... FOR EXAMPLE: (sealed box 2 subs same airspace, one stops playing, the other one doesn't and blows the cone out of the other one beause of the presure imbalance) the way i see it... if there is no phase cancellation, then i will simply hear the louder size sub at the given frequency more than the lesser, the benefit to this setup is doubling the optimal effective range of the bass, example: 10's play high frequencies better than low bass and 15's play low bass better than high bass... thats just common sense and physics

 

[DFW40 10+ year member]

The 13.5 might be a tad bit more effeceint at the lowest frequency but there is very little difference on which plays lower better. Your box will have more to do with this than the subs.

 

[cotjones 10+ year member]

The 13.5 might be a tad bit more effeceint at the lowest frequency but there is very little difference on which plays lower better. Your box will have more to do with this than the subs.

well i i did try different size boxes with just the 10's but the 13 has a commanding lead in feel over them... its more natural... on paper i'm shure it would work fine but there are parts of a sound wave not tuneable that make a 13 sound better on deeper notes... (bigger drums play lower notes) a sub is different than a drum in that it uses an electromagnetic signal to produce a certain frequency... but they are the same in that there is an optimal frequency for them... having 2 different size subs expands that optimal range... you ever heard of a 15" tweeter... or a 4 inch tweeter for that matter... i've seen one but the aren't very practical or common... its because speaker manufacturer's know that the easiest way to achieve a specific frequency is by optimizing the size of the cone for that frequency... the same concept birthed 2 way speakers and eventually 3 way... the difference is that as you go down in frequency, the difference between frequencies becomes greater (so you can hear the difference between 25 and 26 hertz better than you can hear the difference between 200 and 201 hertz and you certainly would have a hard time hearing the difference between 1000 and 1001... all the more reason to optimize bass systems for specific frequencies just like front stage... even 10 hertz is a big difference

 

[alteraudiousa 10+ year member]

the 13 will have a much easier time playing the lower frequencies. As for the 10s overpowering the 13 they won't be as big a problem you guys are making it out to be if he does it right. Since the 10 won't play too much below say 60hz and the 13 plays up to 45hz and not much after that, one won't overpower the other cause one isn't playing the same frequencies as the other. If you are able to blend the crossover points and slope and overall volume of the subs than you should be able to make it sound quite nice. You will probably want steep slopes to make sure that the crossover points overlap too much. Like i said he can get it done right than it will work, but it takes a whole lot of everything from processors and labor.

 

[DFW40 10+ year member]

well i i did try different size boxes with just the 10's but the 13 has a commanding lead in feel over them... its more natural... on paper i'm shure it would work fine but there are parts of a sound wave not tuneable that make a 13 sound better on deeper notes... (bigger drums play lower notes) a sub is different than a drum in that it uses an electromagnetic signal to produce a certain frequency... but they are the same in that there is an optimal frequency for them... having 2 different size subs expands that optimal range... you ever heard of a 15" tweeter... or a 4 inch tweeter for that matter... i've seen one but the aren't very practical or common... its because speaker manufacturer's know that the easiest way to achieve a specific frequency is by optimizing the size of the cone for that frequency... the same concept birthed 2 way speakers and eventually 3 way... the difference is that as you go down in frequency, the difference between frequencies becomes greater (so you can hear the difference between 25 and 26 hertz better than you can hear the difference between 200 and 201 hertz and you certainly would have a hard time hearing the difference between 1000 and 1001... all the more reason to optimize bass systems for specific frequencies just like front stage... even 10 hertz is a big difference

In this case you should go with an 18 inch sub for the low notes and 8 inch subs for the higher!!

 

[cotjones 10+ year member]

In this case you should go with an 18 inch sub for the low notes and 8 inch subs for the higher!!

stuck on JL lol so if a 13w6 can't go low enough... its probly because it would rupture the fabric of the universe... nah ignorant of me to say but i really do love the sound of the jl's better than anything i've heard beside maby focals... just personal prefference... but ideally ur right actually the more differnt sized subs you have, theoreticaly the more acurate bass reproduction you have... and more spl resulting... but to me there is a fine line to how much this system practically makes sense sound's and looks good, and i've found it to be 13 and 4 10's .... (you'd need about 8 8's vs. an 18 of the same series) lol and i ain't really down with kicker's sq even a lil bit

 

[Ninteens 10+ year member]

The best way to adjust your xovers and tune everything would be to find an SPL meter.

Play a tone sweep at a lower volume and look at the results. Using that method you could set your xovers and gains to get the flattest response.

You could get by with a radioshack spl meter. You can buy them for about $36.

 

[mlstrass 5,000+ posts]

Question: why would you want the 10's to play up to 90Hz? Seems a little high and they might actually roll off before that.

And why can't you underlap the xovers? Cut the 13 around 35-40, so by the time the slope rolls off it won't overlap with the 45Hz that the 10's are taking over at. Might need a small hole in the middle is all. Seems like some time with an SPL meter and test tones would be all it takes.

And it's not like some guys don't spend countless hours setting xovers, time alignment, etc.. with their front stage.

Does anyone have a link to an actual test where it was proved that 2 different sized subs playing different frequecies caused cancellation? Otherwise it's a lot of speculation.

Sounds interesting, good luck and report on your results, seriously.