Sub placement, does it matter?

[MellowHype 10+ year member]

Of course the front wave from the cone may cause some issues with the mouth of the port on the outside if it's in #1 .
OP, couldn't you go right in the middle? That way the sub isn't too close to either opening of the port.

I find that position of the box and port in the vehicle has a much more dramatic effect on output and response than just moving the sub from one side to another of the baffle.... moving position of the sub (to the top, back, or side) of the box may also make a noticeable difference. Nothing for it but to build a dozen boxes for that car, buy a meter, and test..... OR if you can find someone who has built a lot of boxes for the same car they can probably tell you what works best.

If thats whats recommended, then ill do it, you guys no more than me lol

Any yeah i think i noticed an increase in spl when i turned my box over faced up from a normal upright, but that was probably because the woofer was sitting so close to the tail gate

And another thing, that RE Box calculator says for the side cuts, 15.25 x 12 x 15.25 x 12.. Why twice?

 

[hispls 5,000+ posts]

If thats whats recommended, then ill do it, you guys no more than me lol
Any yeah i think i noticed an increase in spl when i turned my box over faced up from a normal upright, but that was probably because the woofer was sitting so close to the tail gate

And another thing, that RE Box calculator says for the side cuts, 15.25 x 12 x 15.25 x 12.. Why twice?

It is always worth experimenting with which direction is best to aim the woofer and moving it closer and farther from the rear wall of the vehicle can make a noticeable difference. Most people with hatchbacks do sub up and port to the rear or port to the side. Trunks I've seen go sub back port to side, or sub up and port front. You'd do well to do a little research on what works well for your vehicle before you start cutting wood. From what I understand it's not so cheap in Europe as it is over this way. At 36$ a sheet people in USA can afford to build a few boxes to test, if it's 80$ or more that gets a little painful.

 

[MellowHype 10+ year member]

It is always worth experimenting with which direction is best to aim the woofer and moving it closer and farther from the rear wall of the vehicle can make a noticeable difference. Most people with hatchbacks do sub up and port to the rear or port to the side. Trunks I've seen go sub back port to side, or sub up and port front. You'd do well to do a little research on what works well for your vehicle before you start cutting wood. From what I understand it's not so cheap in Europe as it is over this way. At 36$ a sheet people in USA can afford to build a few boxes to test, if it's 80$ or more that gets a little painful.

I can actually get an MDF sheet (3/4 inch) for about the equivalent to $23, or get a sheet cut down into all my pieces for around $33, thats an 8x4 sheet.

I have a hatchback and since the RE box calculator is all im familiar with itl have to be a simple design on that, so its gonna be sub up & port up. Im just hoping the extra capacity inside this box will give a nice difference. Currently running in a box that was 2.0 ft^3 @32 hz before displacement, and the new will be 2.5ft^3 and whatever hz it needs to be that after subs in its at 32hz (still dont know how to work it out and cant find much on google)

Ive also just found out i can run my current dual 4 ohm at 1 ohm if i get another sub, which means ill be running 500watts each, seems like a good idea and im only loosing 200rms of power but gaining 12" more sub //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[MellowHype 10+ year member]

Heres my current set up and space restrictions, sorry for the bad quality

So ive got about half inch i can squeeze between the amps, so il have a little more room to mount the sub, thats currently a 12" sub on a 12" high piece.

decided another 4ohm sub running both at 1 ohm is what i want to do, so as soon as i know what to do with the box i can go purchase it and get going.

I can get a maximum of 37" side to side, and i think it was 34" between where the subs can be mounted to avoid them hitting the plastic bits (i marked one in yellow)

Can i use the same port as the one in the OP or will it have to be completely different? like port in the middle or what ever

 

[ancorp 10+ year member]

So you can either make box 37" wide but less tall, or 34" and taller. If you go 34" wide, how tall and deep can you go maximum? You can always mount the amps on the left and right side of the box below those plastic bumps if you make the box 34" wide.

 

[fivedollapizza 10+ year member]

you should definitely download Torres to double check everything. completely design the box in the RE builder so you know what you're looking at, then take those numbers and put them into Torres. i bet the tuning is higher than RE says it really is.

good call on asking everyone here. i've only had to rebuild my box once after questions on these forums, and that was just to put the port to the drivers side (which was actually suggested to me, i just didn't listen lol)

 

[MellowHype 10+ year member]

So you can either make box 37" wide but less tall, or 34" and taller. If you go 34" wide, how tall and deep can you go maximum? You can always mount the amps on the left and right side of the box below those plastic bumps if you make the box 34" wide.

Just checked and if i had it so that it was 34" wide and centred i could have it a maximum of 3.5 inches higher, any more or even 3.5 and the subs will be slapping against the parcel shelf, and the port will be like an inch or two from the shelf.

removing the shelf isnt an option either i cant risk displaying the system overnight etc

you should definitely download Torres to double check everything. completely design the box in the RE builder so you know what you're looking at, then take those numbers and put them into Torres. i bet the tuning is higher than RE says it really is.
good call on asking everyone here. i've only had to rebuild my box once after questions on these forums, and that was just to put the port to the drivers side (which was actually suggested to me, i just didn't listen lol)

ive got a youtube video open for that im gonna watch it and learn how to use it to make sure.

Btw, just to be clear the box will be like in the OP with both 1&2 subs, and then just flipped up so that the subs facing up.

Can anyone tell me how i can work out displacement and hertz after sub displacement? once i know that and how to go about placing the 2nd port wall im ready to go and order the second SWR-1243d, i think its gonna be hard to find one as the new R is out.

I watched 'ExoContralto' sub box tutorial and he used the RE calculator and just moved the second portwall but i dont understand how he got the 3.5" measurement

said video


@ 2:40 ish

Edit: probably me being an idiot, just realised its the width of the actual port, might aswell make sure thats correct. I just move the second wall but make sure it leaves the same size gap as the port opening

 

[fivedollapizza 10+ year member]

i don't remember off hte top of my head which spec is subwoofer displacement, but .07 is a good general to add in for a 12" driver.

when you throw your numbers into Torres there will be a box to input additional displacements for the driver and any bracing.

exactly correct about where the second port wall goes. just stays port width away from the back of the box.

 

[MellowHype 10+ year member]

i don't remember off hte top of my head which spec is subwoofer displacement, but .07 is a good general to add in for a 12" driver.
when you throw your numbers into Torres there will be a box to input additional displacements for the driver and any bracing.

exactly correct about where the second port wall goes. just stays port width away from the back of the box.

Mounting Depth: 162mm (6-3/8'')

Mounting Diameter: 275mm (10-13/16'')

Displacement: 0.100ft^3

Added Volume: 0.090ft^3

In that video it states to aim for 31/30hz to get a target tuning of 32hz after displacement, so im gonna go with that, and aim for as much ft^3 as i can squeeze in and use a similar port to he used in the video.

So say im using dual subs and the box ends up 3.0ft^3 with each sub =

Displacement: 0.100ft^3

Added Volume: 0.090ft^3

what would it be after displacement? i dont understand how its worked out or what added volume is

From what i remember people on here used to recommend 2.0-2.5ft^3 for a single R so i really need to make this box as big as i can squeeze in

Edit:

this is what i can do @ 37 inches wide

When coming up with the 34" wide box i think i realised how much more room i can potentially have but im gonna need to double check this all over tomorow when ive relaxed a bit lol, i just really wanna get this build going.

Potentially can have this, but i know for a fact the amps will have to be mounted on the sides of the box

So a lot more volume than the 37", im just worried about the port only being 2.5". However if i bump it to 3" the second wall has to be 18" and thats not gonna fit the in the way like the 1st pic (how either will be with the second wall like that)

Thanks for all your help guys i really appreciate it.

 

[MellowHype 10+ year member]

I have now found out another version of my sub isnt gonna be easy to get, the sub is discontinued in everyone of my local/online shops. Might have to sell mine and get two newer type R's

 

[ancorp 10+ year member]

Your best bet for your space - 34" wide, 19" tall, 14" deep - One 16" long 6" diameter aero/flared round port, at the side of the enclosure closer to the bottom. That'd give you 4.11 cubes before displacement, 0.2 for the two subs, 0.26 for the port - 3.65 cubic feet net. 32HZ tuning after all displacements. Would work great for either these or the newer gen Type Rs

 

[MellowHype 10+ year member]

Your best bet for your space - 34" wide, 19" tall, 14" deep - One 16" long 6" diameter aero/flared round port, at the side of the enclosure closer to the bottom. That'd give you 4.11 cubes before displacement, 0.2 for the two subs, 0.26 for the port - 3.65 cubic feet net. 32HZ tuning after all displacements. Would work great for either these or the newer gen Type Rs

For an aero port, is that just one big box with a hole cut out and 16"long PVC pipe with flared out ends slotted into the hole? nothing else going on inside the box?

Might give that a go, but im now looking at trying to get a couple of sandown sa-12's shipped because i realise how stupid UK's prices are, a type R costs me the equivalent of $233, where a SA-12 is $199, not sure what the shipping rates would be though for 2 12's

Could anyone tell me whether im going to notice a big difference going from one 12 @ 700w (2ohm) to 2 x 12 @1000w (1ohm). Does that extra 200 watt become irreverent when losing 200watt but gaining another 12? Just worried as it started being a cheap quick upgrade with one more sub, now im gonna need two new subs no matter what

 

[MellowHype 10+ year member]

For an aero port, is that just one big box with a hole cut out and 16"long PVC pipe with flared out ends slotted into the hole? nothing else going on inside the box?

Bump

Just went and collected the two R's, gonna go get some wood cut tomorow and get building over the weekend.

My next step is probably finding a 1ohm stable 2000rms amp for a reasonable price, the R's will have to just be on 500rms for a while.

 

[MellowHype 10+ year member]

Turns out i cant get either of those sizes in my trunk! i wasnt taking into account the fact that the seats slant as the height of the box rises, or the fact that i need to have room to mount my amps

The true size ive come up with and i think its the best i can do with a simple box, is 33 wide, 19" height and 15" depth, then mounting the subs on top. I think it can be done but the subs might be tight, due to leaving room for the portwall (2.5 port, and second wall being parallel to 1st with 2.5" gap between), but two 12"s should fit.

Ive made a mock up box from proplex sheets, of those dimensions and im going to see if it fits tomorow.

That gives me a 3.6ft^3 31hz box before displacement, is that just too small for two R's? a 2.5" port seems small aswell?

I can possibly gain another inch or two in height, giving me a max of 4ft^3, but i will have to lose my parcel shelf, and i dont want to display my system overnight etc, and covering it with a sheet just makes it obvious ive got something to hide. could anyone suggest what i could do about that? i was thinking of just covering it with a thin carpet that matches the cars interior to try to make it look like a shelf, and just remove it and tuck it behind the sub when i leave the car.

This is what my boot looks like

 

[ancorp 10+ year member]

33 x 19 x 15 is actually a bit bigger then the 34 x 19 x 14 I was discussing earlier. The Rs will do just fine. But yes, do an aero port to save space. They're more efficient then slot ports. They are indeed PVC or cardboard (sonotube) pipes with flared ends. One 6" will be fine.