I need box recommendations for 2 Sundown U 15s

[BrandonScott]

Whats up bass heads. I recently got a pair of sundown U series 15s, dual 2 ohm. I have a 2006 double cab toyota tundra and obviously, 1st thing i did was took my back seats completely out. Lol. Im looking for box recomendations for these 2 sundown U 15s. I currently have 2 american bass xfl 15s in a 8 cubic box tuned to 32 hertz. Subs up port facing driverside door. Port area is 120 cubic inches. Huge port! They absolutely slam. But im taking them out and installing these sundowns. Could i just drop them in this same box? 

This is everything i am installing this week-

1 Deaf bonce apocalypse AAK 4000.1 amp

2 sundown U series 15s

1 pioneer DEH-S6220BS head unit

2 DS18 neo pro 6.5 loudspeakers

4 memphis audio 6.5 in the doors

1 Deaf Bonce Apocalypse 1000 watt 2 channel amp For the ds 18 6.5s

I already have-

1 brand new agm under the hood

1 brand new yellow top optima inside

1 Xs power 630 farad super cap 

All 0 gauge ofc and 10 gauge ofc for subs and 14 ofc for speakers. HO alt coming soon. Im currently running the xfl 15s and a taramps md 8k.

Any help is much appreciated.  

Thanks guys.

[Joe X]

That box is larrer than recommended for Sundown U 15s but so is for the XFLs LOL.

 

Just swap them and see how it goes, port area is more than enough, if you find them too peaky is a matter of reducing the Net volume, there are many ways to do it like using blocks of polystyrene.

 

When using large boxes one just need to setup the subsonic filter right and paying attention with power, you need yo keep within Xmax for the long term reliability of the subs.

[BrandonScott]

Thanks, i was thinking my box was a little big for the sundowns. I know its oversized for the xfl as well. But i usually go about 10-20% larger than recomended by the manufacturer. I find that i can get a little lower that way, but also use less power to do so.  But i want to get the most i can out of the sundowns so i think im going to try a new build. Im thinking port in the middle facing front seats, and subs up. Although, subs up tend to make my roof do that crazy metal wobbling sound that i hate. Maybe its time to build a birchwood roof. Lol

Anyways, im thinking subs up port center facing forward,  7 cubic ft tuned to 32 hertz. 

Also i have a nice 8" aero port just sitting around. Could u use that for the 2 sundown 15s? Or would it need a larger aero? It seems like it would be enough. 

I will include a pic of my sundown U 12s and the box they are in. Im thinking if doing an exact replica of that box but for 15s.  The one my 12s are in is 4 cubic ft tuned to 32

[Joe X]

That's an awesome box but for an SUV! If you want to help with the roof flex then subs forward / port sideways.

 

The 8" pipe has an area of about 50 square inches so no good.

 

I would test the Sundowns in that box just to know where you are at against the XFLs and the net volume, if they are overly peaky then smaller box but I am betting you are used to the large boxes sound.

[BrandonScott]

Good idea. I havent had a box subs forward port side yet in the trucj. I think that might be ideal. Thats what im going to try. Thanks joe x. I have however had subs forward and port up and that still did roof flex but i had way harder hits to the fromt seats from the subs. It sounded really good. But thats definitely what im going with now. I'll post oics after i complete it so you guys can check it out. And i am going to try them in the xfl box just to get an idea. I think i need to be more around 6.5-7 cubes and around 34 hertz. About 100 inches of port area. 

[Joe X]

Your ideal box specs will come after testing in your current box, you will know if you want lower tuning and how clean they sound, usually a smaller box will produce better definition in  the sound at cost of efficiency, Listen in and you will figure what is needed for your new box pretty fast.

[BrandonScott]

Ok, so i got the sundown U 15s in the xfl box tonight. I played them some and they sound really clean but not as low. I think its definitely too much port area for them. It is 120 inches of port. I believe the U 15s call for 48 per sub at about 3 cubic ft. But they do sound good. They do max out pretty quick tho. I think the 8 cubic ft is a little much but i believe its mainly the port area that is off. So.... i think my final thoughts are going to be 6.5 cubic ft, 94 inches of port area, tuned to 33-34 hertz. I believe sundown calls for 35 on the U series so ima go in-between at hang about 33-34. We will see. But ima rock them in this xfl box for a few days and get the feel of them. The spiders are still stiff too because they are pretty new. So that will make a difference too right? After they are broken in they will sound different. Anyways, im definitely doing the subs forward, port to the side. Any thoughts on the port? What port style should i go with? 

Regular slot port? Aero port?  square port? Octoport? And if i do the aero port, should i do 2 x 8"  tubes? Or like 3 x 6"  tubes? Im leaning towards a straight slot port

[Joe X]

As the suspension looses they will play lower better but also make them hit mechanical limits easier, give them a week or two to know what they actually do.

 

Maybe I should look at the models for both of your subs, I will get back to you.

 

The port to do depends very much on your situation, all port types can work, a non turning kerfed slot port can be all you need if you can keep a low area ratio,  flared round port are best used in extreme SPL as well as extreme sound quality setups.