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View Full Version : Help with box for two 12s.



SquishY
08-25-2011, 06:19 PM
Anyone mind helping design a crx style box for my not crx? Got 38.5" wide x 24" deep x 14" tall to go in a '00 Tiburon. Aiming for two undecided 12s and a new AQ 3500. Electrical is going to be upgraded as well, no worries.

sacsking916
08-25-2011, 07:40 PM
hard to design a box with no woofers to reference too bro

SquishY
08-28-2011, 09:55 PM
Didn't think of that, sorry. Its been going on two years since I had anything to do with this. I've been eyeballing some Sundown Nightshades for the 12s. But if you think some 15s could fit in there I'll go with AQ HDC 15s in that case.
Guess it should also be mentioned that I do want a tune in the low 30s.

05trailblazer
08-28-2011, 10:07 PM
just 1 15??

mylows10
08-28-2011, 10:11 PM
how bout a 18 night shade

05trailblazer
08-28-2011, 10:16 PM
^^ bump

05trailblazer
08-28-2011, 10:17 PM
^^ bump

morespl
08-28-2011, 10:42 PM
Didn't think of that, sorry. Its been going on two years since I had anything to do with this. I've been eyeballing some Sundown Nightshades for the 12s. But if you think some 15s could fit in there I'll go with AQ HDC 15s in that case.
Guess it should also be mentioned that I do want a tune in the low 30s.
Talk to desinde he had a tiburon doing a 155 with two sundown ns 15s If you weren't so far he would sell you the box but he's on the border of in an il.

morespl
08-28-2011, 10:42 PM
Didn't think of that, sorry. Its been going on two years since I had anything to do with this. I've been eyeballing some Sundown Nightshades for the 12s. But if you think some 15s could fit in there I'll go with AQ HDC 15s in that case.
Guess it should also be mentioned that I do want a tune in the low 30s.
Talk to desinde he had a tiburon doing a 155 with two sundown ns 15s If you weren't so far he would sell you the box but he's on the border of in an il.

SquishY
08-29-2011, 09:46 PM
I'll look him up. I'd do two 15s if I can fit em without messing with the back seat. One 18 might could work though, can a nightshade take 4k daily and could I expect good numbers with a low 30s tune? This is the first time I'm even really considering competing but it must be a good daily ground pounder at the same time.

Moble Enclosurs
08-29-2011, 10:32 PM
I recommend the single 18. It will allow for more room for the enclosure to occupy. This will be likely more efficient than dual 15s in that space if designed right.

SquishY
08-29-2011, 11:03 PM
Sounds good, one 18 could most certainly be fun.
To get my full 24" deep would it be of best interest to do the ports on the sides of the box where the hatch area widens out instead of taking a couple inches off the box or choking the ports on the car? I built a box in a friends Eclipse like that a while back and it sounded and performed well for the little planning that went into it.

Moble Enclosurs
08-30-2011, 12:21 AM
Sounds good, one 18 could most certainly be fun.
To get my full 24" deep would it be of best interest to do the ports on the sides of the box where the hatch area widens out instead of taking a couple inches off the box or choking the ports on the car? I built a box in a friends Eclipse like that a while back and it sounded and performed well for the little planning that went into it.

That makes sense only if you were worried about mounting issues mainly. Compression is compression regardless of where the ports are located. But, yes, for a sense of stability in the physical part of the design, by all means. Now, when the port is calculated, it may need to wrap to the rear of the enclosure as well, so if this is needed, as it does sound like you are wanting slot ports, then make sure the port does not interfere with mounting the driver.
Not sure if this answers the concern correctly, as I am not quite sure what the layout is in your trunk, so if my answer does not fit the concern, please let me know in more detail what you mean by port location.

pro-rabbit
08-30-2011, 12:26 AM
Are you going for SPL or actual plan using this thing daily?

SquishY
08-30-2011, 10:40 AM
Daily. My space is shaped kind of like the box in your sign, moble. The hatch is maybe like 48" at the back so if the ports aim into there then I could have the full 24" front to back. Really want use round ports.

Moble Enclosurs
08-30-2011, 11:15 AM
Daily. My space is shaped kind of like the box in your sign, moble. The hatch is maybe like 48" at the back so if the ports aim into there then I could have the full 24" front to back. Really want use round ports.

Can you show a pic of the area? Take a pic and post it? If it is daily, then placement may not be as much of a concern to you, but if it is, it may be recommended to have one of us design it for you. I just want to make sure you get what you want. But even from the details, I cannot put a picture in my head yet, I apologize. So, a posted pic of the space and idea visually will help a lot, if possible.

SquishY
08-30-2011, 09:12 PM
http://carphotos.cardomain.com/ride_images/3/2851/2541/32126270005_large.jpg
Not mine but same car, to think about it I could probably go a maybe another two inchs in height on the box if I take out the little board thing across the top and just get some tint.

hispls
08-30-2011, 09:16 PM
If you plan to run 4KW you should really go back to your 2 sub plan. Nightshade is a monster sub that handles power and plays low but the coils get smelly after about half a song at 3KW.

There isn't a sub out there that'll really handle 4KW continuous for more than a couple minutes without trouble.

Moble Enclosurs
08-30-2011, 09:22 PM
So, were you thinking of maybe putting the ports facing into these spaces since they are extended?
http://img31.imageshack.us/img31/53/32126270005large.jpg (http://imageshack.us/photo/my-images/31/32126270005large.jpg/)

SquishY
08-31-2011, 02:11 PM
Precisely, so then maybe two nightshade 12s? I really want to run an AQ3500. Two 15s doesn't sound plausible in only 5 cubes after all the displacements come out, or should I stick with the one 18 and do less power, like an other AQ2200 that was on my Mayhem? I never got it tested but I'd be willing to bet it was puting out a lot more than rated and it was happy at .5 ohm daily.

Moble Enclosurs
08-31-2011, 03:21 PM
Precisely, so then maybe two nightshade 12s? I really want to run an AQ3500. Two 15s doesn't sound plausible in only 5 cubes after all the displacements come out, or should I stick with the one 18 and do less power, like an other AQ2200 that was on my Mayhem? I never got it tested but I'd be willing to bet it was puting out a lot more than rated and it was happy at .5 ohm daily.

Looking at the layout, I believe 2 12s may be a better option, or even 2 10s. I can do wonders with 2 10s for you if your interested. Personally, instead of worrying about choosing either a single 18 or 2 smaller drivers, why not calculate for both? You could see which gives you more of what you are looking for in a response and output. Generally, I like to use smaller drivers, as size does not determine output, when you are limited to a certain space. SO, now that I see the area, I would personally recommend dual 10s in a common chamber-this comes from years of experience in acoustics.

SquishY
08-31-2011, 10:15 PM
I've gotten nice results from two 10s in my trunk car and suv, but just two of them doesn't have the ground pounder feel that I'm looking for here. Could we go back to my original two 12s, bunch of power and low tune? TBH here, I said before about competing but I couldn't care less if it put up ****** numbers so long as it moves hella air.

Moble Enclosurs
09-01-2011, 07:43 AM
I've gotten nice results from two 10s in my trunk car and suv, but just two of them doesn't have the ground pounder feel that I'm looking for here. Could we go back to my original two 12s, bunch of power and low tune? TBH here, I said before about competing but I couldn't care less if it put up ****** numbers so long as it moves hella air.

Well, in that case, if you are less concerned with numbers and more concerned with pressure, then you should go with what has more cone area, power handling, and linear excursion capabilities. It comes pretty close with the two 12s and a single 18 on cone area, so measure them and figure which has the most. Likely, the 18 will follow with more power handling and higher excursion as well. If overall, the 18 gives you more of these factors, go with it, just make sure you have room to balance enclosure volume with displacement for a proper enclosure for this driver.
The 10s can put up numbers just as well as the 18 can, but the 18 can likely get more pressure in the LF range of the response more efficiently, so if that is your goal, go with the directions I just stated about those three factors.

SquishY
09-01-2011, 05:39 PM
18 is slightly more cone area, by like 26^2 inches over two 12s. If comparing the same two subs then the 18 would be a clear win except for power handing since it's not getting split between two and I can't seem to find a sub that would be happy with my hopes of 4k.
What about running the AQ at 2ohm and getting probably close to 3k? I'm on a quest to find a pic of a birthsheet from one.

Moble Enclosurs
09-01-2011, 05:43 PM
What are the basic specs on the AQ? Make sure that is can run more than 3K on 2ohms as transfer loss will occur between the wires thickness and lengths and impedance levels of the drivers and such. What is the max rating of this amplifier @ 1ohm?

SquishY
09-01-2011, 05:57 PM
Site says 4300@1ohm and 2600@2ohm. I figure it to likely be underrated by at least a little. I do try to keep my sup wires short and thick

Moble Enclosurs
09-01-2011, 06:07 PM
Site says 4300@1ohm and 2600@2ohm. I figure it to likely be underrated by at least a little. I do try to keep my sup wires short and thick

True. It is an AQ so likely. All you need to do is make sure the 18 is a dual 4. And you will be close enough to 2ohms in parallel.....it will slightly vary based on frequency, but nominally, 2ohms.

---------- Post added at 06:07 PM ---------- Previous post was at 06:06 PM ----------


Site says 4300@1ohm and 2600@2ohm. I figure it to likely be underrated by at least a little. I do try to keep my sup wires short and thick

True. It is an AQ so likely. All you need to do is make sure the 18 is a dual 4. And you will be close enough to 2ohms in parallel.....it will slightly vary based on frequency, but nominally, 2ohms.

SquishY
09-01-2011, 06:21 PM
Sweet, and doing that leaves me plenty of power for future use. You sir have helped immensely in this. Its been far too long since I did any of this.
I did do a little port calculating and came to I think ~28" length for two 6" round ports in a 4.5 cube box for a 32hz tune. That part was always a little confusing to me, those two big *** ports are going to displace a fair amount of air, should I find out just how much and add that bit of space on top of the 4.5 or what? I'd be willing to paypal out a few bucks for a simple box design.
Why D4 to get 2ohm, why not D1?

Moble Enclosurs
09-01-2011, 06:50 PM
No problem, glad to help. It can get Much Much more complex than this but not necessary for what you are trying to do, so you should be all set. Glad you got the port figured out. And yes, those are some pretty good sized ports...fairly long but if thats what it says to use then go for it. But again, if you would like me to figure a design for you, without worrying about too much detail, I can do that, just PM me. or I can verify what you have as well.