Box for 4 SoundQubed HDS3-12s

[BoogerMan]

Hey Everyone,

I'm looking for a little help with a box design for 4 SQ HDS3 12s.

A little background:

It is going in the back seat (back seats removed) of a 2011 Toyota Camry SE.

It cannot be a wall because it is my daily driver and I have to see out my back window

I'm going for a daily ground pounder that can maybe do 150db

I'll be going to 10-12 local shows a year so I want the subs to be visible

I would like it to be about 10 cubes after displacement

I am thinking about doing 2 8" aero ports tuned to 36 hz

My main restrictions are width (48" max) and height (24" max). Depth can vary as needed to get the right cubic foot

My first thought was to do subs up, ports up and use the back of the box to seal off the cab from the trunk.

Hispls was nice enough to help me out a little already in my build log and offered this idea. It is best explained using a pic so here it is. Hispls suggested subs and ports firing against the back wall that seals the trunk from the cab, but since I'll be going to some shows and want the subs to be more visible, I drew the design with subs up and ports firing against the back wall.

So what does everyone think? Should I go with this design? Any other ideas for a back seat non wall ground pounder?

Thanks!

Click to read more...

 

[BoogerMan]

These are the 8" aeros I am thinking of going with. They seem nice? Hard to find 8" aeros.

8" Flared Port Tube Each 8 inch Aero Port Aeroport Black | eBay

 

[Jeffdachef 5,000+ posts]

23.5H x 48w x 22 with two 8" aero or sonotubes 12 inches long. Double baffled and threaded rods for bracing. Should be a little bit above 10 cubes tuned to 36hz. What sub loading and port orientation are you going with this?

You can also do a single 12" sonotube or octoport at 15 length if you want more port area to them.

Sonotubes

 

[BoogerMan]

Should I double baffle all sides? I was going to double baffle the top so I could have the recessed sub look (I think that's what it is called?)

I'm going with 3/4" Baltic Birch wood (sold in 5'x5' sheets so it is supposed to be the real deal, not the junk from Home Depot).

Are threaded rods better than 2" wooden dowels for bracing? I think wooden dowels are cheaper and seem to work well enough, but I'm sure you know what is better?

I like how cheap the sonotube is, but it is not flared. Does the flared end really make that much of a difference?

I was going to do subs up and port back like in the drawing in my first post. Do you think the idea of Firing the ports off the piece of wood that I use to seal off the cab from the truck will work?

Or should I go with subs up, port up, and use the back of the box to seal off the trunk from the cab?

 

[Jeffdachef 5,000+ posts]

Should I double baffle all sides? I was going to double baffle the top so I could have the recessed sub look (I think that's what it is called?)
I'm going with 3/4" Baltic Birch wood (sold in 5'x5' sheets so it is supposed to be the real deal, not the junk from Home Depot).

Are threaded rods better than 2" wooden dowels for bracing? I think wooden dowels are cheaper and seem to work well enough, but I'm sure you know what is better?

I like how cheap the sonotube is, but it is not flared. Does the flared end really make that much of a difference?

I was going to do subs up and port back like in the drawing in my first post. Do you think the idea of Firing the ports off the piece of wood that I use to seal off the cab from the truck will work?

Or should I go with subs up, port up, and use the back of the box to seal off the trunk from the cab?

With 4 12s all you need to do is use ample bracing with the threaded rods. No need to double up on all sides, just double baffle is all you need. The recessed fit is called a flush mount. Flared makes little audible difference unless you are trying to chase tenths in comps.

If you can seal off the cabin from the trunk, go right ahead but you might have to go sub up port up or sub up port to the side since i'm sure there will be little breathing room if the port is pointing backwards. You'll want at least half the diameter to the diameter of the round port for it to breathe.

The Threaded rods take up a lot less displacement than dowel rods and is stronger if you use a big washer plate to increase the area of bracing. Wooden dowels work too.

 

[BoogerMan]

With 4 12s all you need to do is use ample bracing with the threaded rods. No need to double up on all sides, just double baffle is all you need. The recessed fit is called a flush mount. Flared makes little audible difference unless you are trying to chase tenths in comps.
If you can seal off the cabin from the trunk, go right ahead but you might have to go sub up port up or sub up port to the side since i'm sure there will be little breathing room if the port is pointing backwards. You'll want at least half the diameter to the diameter of the round port for it to breathe.

The Threaded rods take up a lot less displacement than dowel rods and is stronger if you use a big washer plate to increase the area of bracing. Wooden dowels work too.

Awesome thank you! I forgot the part where the subs are is called the baffle lol. I thought each side was a baffle //content.invisioncic.com/y282845/emoticons/redface.gif.62fdbfe1a101588a808c4cff71bcb942.gif

Okay good deal about the threaded rod. I'll probably go that route unless I have plenty of room to spare for wooden dowels. I'll wait until I start construction to decide.

I'm definitely sealing off the cabin from the trunk. The wood that I'll use for the seal will bolt to the front of this large V brace, or possibly behind it. Whatever works out the best for a good seal. I can't do the port on the side because there will be even less space between the port and the side of the car.

This piece of wood I'll be using as a seal will go up at an angle so I should be able to get the aeros about 6-8" away from the wood seal if I mount them near the middle of the back of the box. Do you think having the port 6-8" away from the back seal will be enough?

If I can't keep the aero port 6-8" away from the back seal for whatever reason, and I end up having to go subs up and port up, do you think it would be best to do all 4 subs on the passenger or driver side and the port on the other? Or should I do 2 subs on the passenger side, the 2 aeros in the middle, and the other 2 subs on the driver side?

 

[Jeffdachef 5,000+ posts]

4 to 8 inches of clearance should be fine if you can fire back. Dont do do the rear seal at an angle just do a straight wall block off. Having the wall they load off of as an angle might cause the sub to unload rather than load properly.

 

[BoogerMan]

4 to 8 inches of clearance should be fine if you can fire back. Dont do do the rear seal at an angle just do a straight wall block off. Having the wall they load off of as an angle might cause the sub to unload rather than load properly.

Okay if the seal has to go straight up then it will definitely have to go behind this huge V brace.

So now I am wondering if the V brace will cause the sound to be weird because the air from the ports will most likely hit some of the v brace before hitting the back wall... I can place the aeros so that they fire directly at the center of the back wall (to attempt to avoid the air from hitting the V brace). If you don't think the V will effect the sound then I'll go ports back. If you think it will, I'll go ports up.

 

[Jeffdachef 5,000+ posts]

Okay if the seal has to go straight up then it will definitely have to go behind this huge V brace.
So now I am wondering if the V brace will cause the sound to be weird because the air from the ports will most likely hit some of the v brace before hitting the back wall... I can place the aeros so that they fire directly at the center of the back wall (to attempt to avoid the air from hitting the V brace). If you don't think the V will effect the sound then I'll go ports back. If you think it will, I'll go ports up.

pictures please

 

[BoogerMan]

pictures please

Thank you so much for the help! This is great!

Imagine the cardboard is my back wall that seals off the trunk from the cabin.

If I have the aero port aiming right where is says "dishwasher" the air should miss most of the V brace. However some air may hit it. What do you think? Port firing back, or port firing up?

 

[Jeffdachef 5,000+ posts]

I think port back should be fine but you'll need to deaden and decouple that v brace with sound deadener and closed cell foam. Just get a hammer and smack that v brace all around and see where the rattles come from.

 

[The_Dealer]

****, how'd I miss this? Better late than never I guess. In for the pics and final outcome.

Sent from my Motorola 2950 Special Edition 3w.

 

[BoogerMan]

I think port back should be fine but you'll need to deaden and decouple that v brace with sound deadener and closed cell foam. Just get a hammer and smack that v brace all around and see where the rattles come from.

Port back it is. Thank you. I can't wait to hear how this sounds!

I'll cover the entire v brace with deadener //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

Where should I use the closed cell foam?

Is great stuff the best thing to use to help with the cabin seal? Is there anything else to use that comes out a little cleaner? I can always make a false panel in the trunk to hide the expanding foam if needed //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Jeffdachef 5,000+ posts]

decoupling is when you prevent two metal surfaces from vibrating against eachother. Where ever you need to do it will appear once the system is in. In a Toyota, rattle treatment is a long and arduous process. I had a corolla and it took months for me to pinpoint all of the rattles and new ones always seem to keep on comming.

The spray foam can be used in any hole or gap. Just get some painter's tape and cover the holes right after you fill it in. This should help condense the spray foam even more and keep things a lot cleaner. I'd also leave the tape on for a month or so before taking it off. It takes literally that long to cure if you do it this way, but the foam will be much denser and harder.

 

[BoogerMan]

[quote name='Jeffdachef']decoupling is when you prevent two metal surfaces from vibrating against eachother. Where ever you need to do it will appear once the system is in. In a Toyota, rattle treatment is a long and arduous process. I had a corolla and it took months for me to pinpoint all of the rattles and new ones always seem to keep on comming.

The spray foam can be used in any hole or gap. Just get some painter's tape and cover the holes right after you fill it in. This should help condense the spray foam even more and keep things a lot cleaner. I'd also leave the tape on for a month or so before taking it off. It takes literally that long to cure if you do it this way, but the foam will be much denser and harder.[/QUOTE]

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?