very simple question

[ultimate157 5,000+ posts]

b) change the frequencies, remember there is a slope to the frequency cutoff. The sub doesn't magically quit playing at 45 hertz and the others begin at 45 hertz.

Ding ding ... reading to see if anyone was going to say that

 

[Beerdrnkr 5,000+ posts]

Is the box there in common chambered? IMO you would have been better running 2 13" JL's and have a 3 way setup with maybe some 7" midbass in the doors or something. Just a thought.

 

[Supergumby5000 5,000+ posts]

whats the huge desire to have two different sized subs? it would be so much easier to just run all the same size and get some midbasses wouldnt it? i dont know if i quite understand the whole thing about you saying you dont have room for midbasses.

 

[maldecido33 10+ year member]

can it be done successfully? yes, however it's VERY difficult to get everything x-overed and tuned just right; there are a ton of variables involved and, with all due respect, you don't sound nearly as knowledgeable when it comes to this as you should be to achieve the results you're looking for.

I'd really recommend selling the 4 10"s and your amp to power them, and buying one more 13, and putting your 1000/1 (i believe thats what you had, iirc) on both 13"s. it will be VERY nice, much better than what you have

edit: just read a little more of the thread, and you want midbass. you can get good midbass out of the doors with a component system, or go with some midbass in some kickpanels. plenty of options for midbass.

 

[lostdaytomorrow 10+ year member]

How are you setting your x-overs to do what you are illustrating? There is roll-off slopes on most x-overs... How can you get a subwoofer to just play a strict freq. range like that?

 

[maldecido33 10+ year member]

(you can't)

 

[Imshirazy 10+ year member]

I'll have to agree with some people here on this one, it will be very difficult to do such a thing.

If things I say have already been mentioned I'm sorry, but I'd rather restate them they say refer to what that guy said.

Indeed they will have to be in different boxes, but I don't think this needs to be stated, I have yet to see someone even try a box with two different sized subs. Reason being should be pretty obviously, Completely different tones result in different vibrations going through the same box, and other complications that will affect sound.

I Suggest that you face the 13 toward the back of the trunk, and the 10s aligned along the side upward toward the backseat, or at 45 - 90 degrees out from facing the trunk.

The largest problem is going to be that the 13 is going to push a lot more air and be far louder than the others. Also, if the trunk is too small the amount of air inside will screw with it a bit too, although with a blazer im sure there won't be a problem. You will undoubtedly have to do a lot of work to get the 15 and 10s equalized. I've set up a 15 and 2 10s and that took me about 1 hour to sound decent, and even after that I wasn't really proud of the sound, but he loved it.

What I had to do was use capacitors in the signal wire to cut off frequencies below around what was 50 or so, and I let the 15 play normal. You'll notice some 4,3,and 2 way speakers will have small capacitors in them, it does this function.

Whoever said it is also right that there is a cutoff point, the crossover won't just immediately stop at 45, so you should probably either find a set of capacitors to do the work for that if you know how to use them (and of course fairly strong capacitors for a sub) or mess with a few equalizers or stagers.

Also what amplifiers are you going to use to run this setup? are you splitting the subwoofer output RCAs? or are you splitting left and right, or connecting the output of one amp to the input of another?

To answer the other person's question, asking why you'd use more than 1 sized sub to cover the spectrum is like asking why component speakers exist.

The fewer notes a woofer (subsonic or non) has to play, the more accurate it is going to be, and a slightly higher SPL may even result.

Imagine a speaker working it's *** off to play the bass drum, snare, hi hat, guitar, synth, ambience, and all other noises in a song, compared to just a mellow hum of lets say 6K hertz. It's going to perform far better at just playing 6K.

Also, an 8 or 10 inch subwoofer cannot handle tones as low as 10-20 hertz as well as a 15 inch subwoofer with same design specs. A 15 covers more area, more air can be moved for those low tones when the cone moves back and forth much more slowly.

As for your setup, there might be a program out there to help you online for setting up your trunk for different sized subs, depending on the size and coverage of your trunk.

All in all i'd much rather pay someone else to tune it though, it's far too complicated to actually enjoy doing IMO.

But good luck, I hope I was at least somewhat helpful.

 

[cotjones 10+ year member]

Ding ding ... reading to see if anyone was going to say that

it won't be completly strict like that but i'm thinking that you won't be able to hear a problem with it even with a 10 hz overlap since the distortion wasn't that great even with the x-overs set the same... and i want this setup because i know(i have been told) that all subs play the same frequency... but smaller subs are capable of playing higher frequencies noticably better than lows and bigger subs are likewise better at lower frequencies and sound worse with higher ones... not just subs, why do you think mids don't normally come in 15"s?

 

[cotjones 10+ year member]

I'll have to agree with some people here on this one, it will be very difficult to do such a thing.
If things I say have already been mentioned I'm sorry, but I'd rather restate them they say refer to what that guy said.

Indeed they will have to be in different boxes, but I don't think this needs to be stated, I have yet to see someone even try a box with two different sized subs. Reason being should be pretty obviously, Completely different tones result in different vibrations going through the same box, and other complications that will affect sound.

I Suggest that you face the 13 toward the back of the trunk, and the 10s aligned along the side upward toward the backseat, or at 45 - 90 degrees out from facing the trunk.

The largest problem is going to be that the 13 is going to push a lot more air and be far louder than the others. Also, if the trunk is too small the amount of air inside will screw with it a bit too, although with a blazer im sure there won't be a problem. You will undoubtedly have to do a lot of work to get the 15 and 10s equalized. I've set up a 15 and 2 10s and that took me about 1 hour to sound decent, and even after that I wasn't really proud of the sound, but he loved it.

What I had to do was use capacitors in the signal wire to cut off frequencies below around what was 50 or so, and I let the 15 play normal. You'll notice some 4,3,and 2 way speakers will have small capacitors in them, it does this function.

Whoever said it is also right that there is a cutoff point, the crossover won't just immediately stop at 45, so you should probably either find a set of capacitors to do the work for that if you know how to use them (and of course fairly strong capacitors for a sub) or mess with a few equalizers or stagers.

Also what amplifiers are you going to use to run this setup? are you splitting the subwoofer output RCAs? or are you splitting left and right, or connecting the output of one amp to the input of another?

To answer the other person's question, asking why you'd use more than 1 sized sub to cover the spectrum is like asking why component speakers exist.

The fewer notes a woofer (subsonic or non) has to play, the more accurate it is going to be, and a slightly higher SPL may even result.

Imagine a speaker working it's *** off to play the bass drum, snare, hi hat, guitar, synth, ambience, and all other noises in a song, compared to just a mellow hum of lets say 6K hertz. It's going to perform far better at just playing 6K.

As for your setup, there might be a program out there to help you online for setting up your trunk for different sized subs, depending on the size and coverage of your trunk.

All in all i'd much rather pay someone else to tune it though, it's far too complicated to actually enjoy doing IMO.

But good luck, I hope I was at least somewhat helpful.

you are amazing best experience i've had threading yet and you understand what i'm aiming for with multiple sizes

 

[cotjones 10+ year member]

to go further on what he said the component idea was my inspiration... i had 3 12's they sounded good and i had been to competions too and they sounded good, all useing the same size subs... all sounding good... but i wanted something better... so i thought well on certain songs it sounds like the sub is fighting too hard to climb up and down frequencies quickly enough and a speaker can only play 1 frequency at a time so why not put 2 seperate sub systems in the same car? its like a component sub system, lol

 

[maldecido33 10+ year member]

everyone understands what you're aiming for(at least everyone with half a lobe), its just EXTREMELY difficult to effectively do it. only a handful of people have ever done it successfully, and it took a ton of work.

edit: if it was easy, wouldn't everyone do this? I mean, I'd run a 6.5, 8, 10, 12, 15, and 18" woofers to truly get the best frequency range possible. Would it work? On paper, (x-over, eq, enclosure, etc. figures), yea, it would work perfect. It would be extremely difficult to design, but it is possible to get a near perfect result on paper.. Real world utilization? Good luck with that; waaaaaaaaaaaaaaaaaaaaaaaaaay to many variables to even do tw subs of different sizes.

please re-read my post.

 

[cotjones 10+ year member]

(you can't)

actually you can

 

[cotjones 10+ year member]

everyone understands what you're aiming for(at least everyone with half a lobe), its just EXTREMELY difficult to effectively do it. only a handful of people have ever done it successfully, and it took a ton of work.
please re-read my post.

you'd be suprized how many people don't know what i'm aiming for... i realize you don't think i have a lot of experience... but the reality is i don't have much experience with blogs.. and i have studies sound and learned everything i could about it for as long as i can remember

 

[cotjones 10+ year member]

everyone understands what you're aiming for(at least everyone with half a lobe), its just EXTREMELY difficult to effectively do it. only a handful of people have ever done it successfully, and it took a ton of work.
edit: if it was easy, wouldn't everyone do this? I mean, I'd run a 6.5, 8, 10, 12, 15, and 18" woofers to truly get the best frequency range possible. Would it work? On paper, (x-over, eq, enclosure, etc. figures), yea, it would work perfect. It would be extremely difficult to design, but it is possible to get a near perfect result on paper.. Real world utilization? Good luck with that; waaaaaaaaaaaaaaaaaaaaaaaaaay to many variables to even do tw subs of different sizes.

please re-read my post.

don't expect it to be easy but i believe it is a way to achieve both higher spl and sq than all same size subs when done correctly

 

[maldecido33 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.