Box for 4 SoundQubed HDS3-12s

[Jeffdachef 5,000+ posts]

[quote name='BoogerMan']Wow thank you for all the great tips and info! I'll have to take out the V brace so I can lay deadener where it bolts to the cab body. I may not need to deaden the whole brace if it is one solid piece of metal. Like you said, Omce the system is in, then I'll realy be able to find the rattles.

Here are some numbers I worked out last night. I'll draw it up when I get the chance, and then maybe @The_Dealer could mock up a nice image of it with that fancy computer program

Box dimensions outer
46" width
21.75" height (double baffle)
24" depth
=13.9ft^3
(2x4 going under the box as a platform)

Box dimensions inner (using 3/4" wood)
44.5" width
19.5" height
22.5" depth
=11.30ft^3 before displacement

Sub displacement
155"^3
x4
=0.36ft^3

Port dimensions
12" diameter sonotube
14.61" length (should tune it to 36hz according to PSP website. I used a cube size of 10.5 which is the number after displacement of everything except the port. Did I do that right?)
=0.96ft^3
*this will be about 11.8"^2 of port area per net cubic foot

Brace dimensions
?? Didn't figure this out yet but let's say 0.41 cubes to be safe haha
=0.41ft^3

total displacement
=1.73ft^3

sub box after displacement
=9.57ft^3
~2.40ft^3 per sub

Should I increase the box slightly to give more cubes per sub or is 2.4 enough?[/QUOTE]

To calculate the port, you actually need to know the space you have AFTER accounting port displacement not before. So that renders most online calculators completely useless and the calculations to get to that point will be a never ending paradox. Gotta use a calculator that does that for you. Your box is currently a lot smaller than projected NET airspace wise and tuned a lot higher. Sub displacement is more around .15 cubes per sub as well.

with 21.75 as outer height and 19.5 as inner height that counts as a triple baffle not a double. You only need one extra one with only 4 12s. These arent 85lb 12s we are dealing with so triple baffle is not necessary at all.

 

[BoogerMan]

To calculate the port, you actually need to know the space you have AFTER accounting port displacement not before. So that renders most online calculators completely useless and the calculations to get to that point will be a never ending paradox. Gotta use a calculator that does that for you. Your box is currently a lot smaller than projected NET airspace wise and tuned a lot higher. Sub displacement is more around .15 cubes per sub as well.
with 21.75 as outer height and 19.5 as inner height that counts as a triple baffle not a double. You only need one extra one with only 4 12s. These arent 85lb 12s we are dealing with so triple baffle is not necessary at all.

Thanks!

Okay so I need to think a little bit. I can't mess with width or height, only depth.

21.75 outer and 19.5 inner came from double baffle on top (1.5") and 0.75" for the bottom sheet.

I didnt think about how I'll be attaching the sheets together so that may change the numbers a bit.

I guess I honesty do not know if it is best to attach the side walls on top of the bottom piece or to the sides of the bottom piece. Does that make any sense?

I should probably leave the numbers to the experts (aka you lol).

So 46" outer width max, 23" outer height max, 28" max depth. Depth is the only number I can change after measuring more exact last night.

Let's go with 10 cubes after displacement of everything, including the port.

SoundQubed says the sub displacement of the HDS312 is 0.09 cubic feet. That's where I got the 0.36 sub displacement from.

Subwoofer Displacement

 

[Jeffdachef 5,000+ posts]

when did their motors get soo small? Just use torres box calculator and work out the numbers. I'd also make the port interchangeable if you want to get best results. Experimentation will lead to much better results.

 

[BoogerMan]

Awesome I'll get that program this weekend. Thank you!

should I make the port interchanagble so I can adjust the length? Not sure how I could make it interchanagble for different diameters. I'm pretty sure you are meaning make it adjustable for the length but I just want to double check //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I think I'm just about set with the box design! Woo hoo!

 

[The_Dealer]

Hey man I haven't forgotten about you, I'm near finished with the design. Had to take some time for myself to finish up my new box. I was getting impatient and told myself it's in the way and I need to finish it lol

Sent from my Motorola 2950 Special Edition 3w.

 

[BoogerMan]

Hey man I haven't forgotten about you, I'm near finished with the design. Had to take some time for myself to finish up my new box. I was getting impatient and told myself it's in the way and I need to finish it lol
Sent from my Motorola 2950 Special Edition 3w.

No worries man! I'm still playing with numbers slightly and I won't start construction until next weekend so no hurry. I'm going to play with Torres Calculator more today and hopefully get final exact numbers. I appreciate you offering to do this //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[BoogerMan]

@The_Dealer I'm sure you were planning on doing something like this too, but i just wanted to post a pic. I'm going to have to mount the subs something like this to keep it within the 46" width. Then maybe I'll put the Soundqubed logo in front of the two middle subs

 

[BoogerMan]

Okay I think these are the numbers I am going with. Things may change slightly once I start getting things laid out with the actual wood, but this should be darn close to the final size.

Sorry for split image. I'm using a virtual machine to run Torres on my mac so the windows screen is tiny! lol

 

[The_Dealer]

Aight I finished up a design, I'll upload it here shortly.

Sent from my Motorola 2950 Special Edition 3w.

 

[dbjunior 10+ year member]

Personally I'd put the subs forward ports up and put the amps in the trunk. It's not the best idea to mount amps to a box especially just a large single layer.

 

[BoogerMan]

Personally I'd put the subs forward ports up and put the amps in the trunk. It's not the best idea to mount amps to a box especially just a large single layer.

Putting the subs forward will put them near the middle of the car which I was told will possibly cause issues. I want to keep the subs and port as far back as possible so that's why I'm going subs up, port back.

I don't want the amps in the trunk because then they won't be visible and there will also be a large gap between the front of the box and the back of the front seats which will look bad IMO.

The amps won't be mounted to the front of the box directly. I know that's what my pic shows but I was in a hurry drawing it.

A sheet of wood will be attached to the front of the box which will come down at an angle (similar to the angle of the front seats) and the amps will mount there.

 

[The_Dealer]

Just use rubber washers to isolate them and I don't see the big deal. Half the pictures I see online of people's setup, the amp is just sitting there not even bolted down.

Anyways, still uploading the pictures. Went through my 4g speed data, so it's taking a minute.

Sent from my Motorola 2950 Special Edition 3w.

 

[BoogerMan]

Just use rubber washers to isolate them and I don't see the big deal. Half the pictures I see online of people's setup, the amp is just sitting there not even bolted down.
Anyways, still uploading the pictures. Went through my 4g speed data, so it's taking a minute.

Sent from my Motorola 2950 Special Edition 3w.

Thanks man! Can't wait to see it. Hopefully I can make it come to life in the next couple weeks //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[The_Dealer]

It's going to be tight fitting the subs and not have one close enough to the port have issues, so I did subs/ port rear. I can move the cutouts and see if they'll fit though



Sent from my Motorola 2950 Special Edition 3w.

 

[BoogerMan]

It's going to be tight fitting the subs and not have one close enough to the port have issues, so I did subs/ port rear. I can move the cutouts and see if they'll fit though

Sent from my Motorola 2950 Special Edition 3w.

Thanks for doing that man! However I'm going with subs up and a 12" round port that will be firing off of the back wall that seals the cab from the trunk. Sorry about the confusion! I have to have the subs up for ease of service if needed and so they are visible for shows. There won't be a lot of room between the back of the box and the trunk seal so I can't do subs back while still being able to access them. And I've been told subs forward would be a bad idea since that would place the subs right at the center of the car (and since this isn't a wall, that would not work out well).

I want to go with a round port so I can make adjustments if needed and it should be easier for me to build compared to a slot port (first time building a box). I plan on tuning to 36hz but I want to be able to play around with that number if 36hz isn't optimal. So subs up, port back.