Help me spec out 2 car sub boxes

EndersShadow

Drenis wrote: »

The sub can face sideways. As long as the driver isn't being choked.

I'm currently doing something VERY similar to the GF's ride with a 12" sub. Hope whatever path you choose works out for you dude.

Yup, this would be for a single TC Sounds 12" sub as well, pushing 1200 watts :eek:.

About to go to lunch and going to do some measurements. Wont be using fiberglass as thats too expensive. Will basically be looking at possibly building a upper case L shaped box with the bottom of the L dipping into that unused space. Will cover the top and sides so it looks like its molded in, but its not.

Would then run the amps and at least one sides crossovers (if not both) on the top of it with a nice cover so you just see the box parts of the amps and crossovers with all the wiring hidden.

Might be able to build this with my Dad since its going to be all box shapes. Would save a bunch on labor as well.

MDF work fine or do I need a different type of wood? Should I go with Pressure treated as well to deal with the possiblity of water in the trunk?

mole'

EndersShadow wrote: »

Ok, so I saw this box below and it gave me an idea and a question.

Question: Does it matter the orientation of the sub within the trunk (i.e. does it need to be facing back, front, sideways, etc.





If it doesnt matter how the sub is mounted, I could do something similar using the rear passenger side of my car, as originally mentioned by Drenis.

I wouldnt do anything fancy with fiberglass, but I could run it the full length of the trunk (23 inches internally volume), the full height (18 inches internally on one end, 23 on the other), and then make it as shallow as possible (~11 inches internally). I would also use the current trunk floormat as a template and build a double hinged access to the spare tire.

A box as long as that would allow me to take my wiring and put it all on one side, and hide it in a box similar to what the pictures above have on the floor.

I would then get back a bunch more trunk space.

BUT this is all assuming orientation of the sub doesnt matter.....

my sub in my SRT-4 came that way from the factory. it's a Kicker system.

Drenis

EndersShadow wrote: »

Yup, this would be for a single TC Sounds 12" sub as well, pushing 1200 watts :eek:.

About to go to lunch and going to do some measurements. Wont be using fiberglass as thats too expensive. Will basically be looking at possibly building a upper case L shaped box with the bottom of the L dipping into that unused space. Will cover the top and sides so it looks like its molded in, but its not.

Would then run the amps and at least one sides crossovers (if not both) on the top of it with a nice cover so you just see the box parts of the amps and crossovers with all the wiring hidden.

Might be able to build this with my Dad since its going to be all box shapes. Would save a bunch on labor as well.

MDF work fine or do I need a different type of wood? Should I go with Pressure treated as well to deal with the possiblity of water in the trunk?

I would definitely stick to MDF. Also, just make sure you let that amp breathe.

Looking forward to seeing a drawing of sorts for the design.

Are you going sealed?

EndersShadow

Drenis wrote: »

I would definitely stick to MDF. Also, just make sure you let that amp breathe.

Looking forward to seeing a drawing of sorts for the design.

Are you going sealed?

Yup, mocking it up right now. Only problem is that I dont think I have enough room on the side to mount both amps side by side either vertical or horizontal.

I have about space about 12" x 17" that they could go on.. but as you see based on their size, that wont work for either....

1200D: 20 inches W x 3 inches H x 13 inches L

125.2: 20 inches W x 3 inches H x 14 inches L

P.S. Drawing an ISO in Word using Lines and Grids SUCKS!!!!!!!!!

dcmartinpc

Why not make the box slightly taller and mount the amps on the sides of the box?

Just a thought...

Don

EndersShadow

dcmartinpc wrote: »

Why not make the box slightly taller and mount the amps on the sides of the box?Don

Looked at that. I simply dont have enough space for it. I could put them so that the 13" and 14" side were vertical as I have 17" total height....BUT I would need 40" of Width (20" + 20") for them to be side by side and I only have 25 to begin with.

Look at the attached pics in my previous post and you will see what I mean

dcmartinpc

EndersShadow wrote: »

Looked at that. I simply dont have enough space for it. I could put them so that the 13" and 14" side were vertical as I have 17" total height....BUT I would need 40" of Width (20" + 20") for them to be side by side and I only have 25 to begin with.

Look at the attached pics in my previous post and you will see what I mean

Gotcha, those weren't there when I first replied. Makes sense now

Don

EndersShadow

dcmartinpc wrote: »

Gotcha, those weren't there when I first replied. Makes sense now

Don

Part of me wonders if I make the boxes deeper and then use some of that height and mount the amps on top the boxes. My only concern is that hot air rises so they will always be surrounded by the hottest air in the trunk.

Might just have to break down and mount them into a seperate compartment on the floor of the trunk. Still thinking on this.

EndersShadow

So I am a "special" kinda guy. I miscalculated the amps by a LARGE margin.

Sundown 125.2: 10" Wide x 13.5" Long x 2.5" High

Sundown 1200D: 10" Wide x 12.5" Long x 2.5" High

I might find a way to work them into the mix. Got time to think this weekend.......

I also am thinking I am going to go ahead and reclaim some of the wheel well area so the box is more like a big rectangle with a section at one end sticking out and a section in the middle going in.

Figure I could just use cut a triangle shape out to fit over the wheel well so I might not have to make the box as deep.

Lots of math today and I hate math :frown:

EndersShadow

Ok, so I built 2 WinISD files, one for the Treo TE (which is in a ported 1.25 cubic foot box) and another for the 12" TC Sound in a 2 cubic foot box.

I have attached them in the zip file here

I think a 3 foot box is just too big for my trunk. A 2 foot box is much more manageable for that space and I think its still going to blow my current setup out of the water.

Also wondering how hard it would be to port the TC Sound box, or add a passive radiator and what if anything that might gain me.

EndersShadow

I mocked up a possible ported box. Its a 2x2x17 port. I only need 1.5 cubic feet and will mount the 1200D on the front of the box right centered on the sub.

Still unsure where the 125.2 would get mounted.

Attached are the mockup and the WinISD file

EndersShadow

Miscalculated the port length. Attached is a better mockup

Drenis

That's an interesting port design.

EndersShadow

Drenis wrote: »

That's an interesting port design.

Its similar to the port in my current box, just not in a corner. I figure center it rather than have the port at one end or the other.

I am thinking I might shorten the 2nd box depth wise so I can mount the other 125.2 on it. So it would be 3 inches shorter and possibly an inch or two deeper.

Its not a big deal to port it a different way. Figure I would use some 1x2 lumber to create it.

But the port allows me to make the box smaller than sealed and get a better response (I think).

I will admit I am not 100 percent sure my WinISD modeling is correct lol

EndersShadow

Had an epiphany last night. What if I had a box that was the entire length and width of the trunk (which are large dimension), with a section cutout to mount the amps and my crossovers/wiring.

The box would be 6" tall (externally) so it would be a 1" sheet of MDF for the floor, 2x4 for the outlines of the box/amp rack and then a 1" bump up for the woofer so its upward firing.

Based on how big it would be I might not need to port it since it could be 2+ cubic feet. Need to get some better measurements today and am then going to mock something up, but I think this idea is the best so far.

Yes I lose 6" in height in my trunk, but that more than likely just makes it flush all the way across the back.

Will mock up a top, front and possibly an ISO view today while the wife is at work.

Best part I already have a template for the top and bottom (the current floor). It would need some slight modifications but thats not a biggie.

I would then get the box built, go to a local installer to have them carpet it and the amp rack section and then could install it WHILE STILL USING MY CURRENT 10" until I get the TC Sounds one.

EndersShadow

I spec'd out responses assuming I can get a 2.5 cubic foot box. The first is in a straight sealed box, the second in one that is ported w/ a 2" x 2" port 7" long.

Both have a lowpass filter applied of 100 hz and a highpass filter of 30hz so I dont bottom out the sub.

You are looking at the SPL graph from WinISD.

EndersShadow

Got the box figured out. Its going to be right at 2 cubic feet. I haven't decided how/if I will be porting it just yet, though if the WinISD files are any indication I should port it.

The plan to make it easy is to make the box 6" tall so I can use 1 x 6's as the outline of the box and then just use plywood on top of that. The box height will be the same all the way across BUT for a small section I need help with. The depth of the box as it stands is 6 3/4 inches but I need 7.15" inches for the sub. Anyone have a good place to get some 12" sub spacers from?

I might be able to mount the speaker crossovers vertically on the opposite side of the amp power and ground, but without having it built and carpeted I cant tell for sure.

Will probably start building it the week my wife is out of town in the evening after I get off work.

In the SPL pdf the green line is the ported box and the yellow is the sealed one.

Parts list is below:

• 1 - 2 sheets of 4ft x 8ft x 3/4in Fir CDX Treated Plywood for the top and bottom of the box.
• 2-3 1 x 4 x 12 Appearance Grade Treated Board for the actual sub box part (the thicker sections in the picture) as well some of the leftover plywood (for the amp surround part)
• 1 Round Speaker Terminal 2-7/8" Gold Spring-Loaded
• 1 TC Sounds LMS-R 12" DVC Subwoofer

EndersShadow

Anyone want to help me figure out how to do a slotted port for this box?

dcmartinpc

EndersShadow wrote: »

Anyone want to help me figure out how to do a slotted port for this box?

Giving you a call...


Don

EndersShadow

Shout out to dcmartinpc for helping me out.

looks like the subsonic filter will be 20hz and I will at ~108 db at 20 hz :biggrin:.

Port is going to be 1" x 6" x 18". There will be some audible port noise but shouldnt be able to hear it as I will have the seats up if I am cranking it and they should kill the noise.

That and I probably wont be at full volume most of the time as this sub will KILL my mains so I will probably have to drop the levels on the sub in order to balance it.

Hopefully will have the schematics finished by end of the week. Just got a couple more tweaks to the system and I should be good.

EndersShadow

Graphed a couple different options out. Basic difference is that each box is tuned 5 hz from the other. So there is a 20 hz, 25 hz, 30 hz tuned box. The Green is the 20hz box, the sky blue the 30, and the purple the 25. Not sure if I really need/want the extra db's between the boxes...

The subsonic filter will be applied at 20hz no doubt at all.

Don any thoughts on port noise differences between these 3 options?



Thoughts?

EndersShadow

I am going to try and figure out why the Treo model I have looks so bad (not on above graph).

I am using the spec's for the 10.44 (attached earlier in the thread). The box itself is 1.2 cubic feet with a 3 1/2 x 3 1/2 x 11 inch port.

Don if you get a chance can you model it and see if you can figure out where I went wrong lol....

I also wonder how much cabin gain I am going to be getting as the 25 hz box depending on cabin gain might be a bit better for overall sound as its just barely below the 20hz ported box at 20hz (end of the graph).

EndersShadow

dcmartinpc:

Looking for a way to drop the port noise to ~20 - 30 m/s if possible (number suggested to me by someone else).

Dont know if this is possible.

EndersShadow

Found an interesting post on the TC Sounds website: http://www.tcsounds.com/forums/index.php?/topic/50-ideal-box-for-12-lms-r/

EndersShadow

Latest iteration of the box. Might be tuning it to 30hz and using 2 4" diameter x 42" ports to keep the port noise low. Not sure just yet.

Crossovers are mounted vertically top to bottom of the box. This leaves me about 1" to wire them. Hope thats enough :biggrin:

EndersShadow

So after a long and hard consideration I think I will be going with a box that is 14 3/4 wide x 14 3/4 tall x 21 1/2 long using 3/4" MDF on all sides and a 1 1/2" baffle for the drivers. Total interior volume works out to be around 2 cubic feet. Drivers will be one TC Sounds 12" LMS-R on one end and on the other a TC Sounds VPM 12" facing the front and back of the trunk. Box will be tuned to 30 hz as I believe this will give me a decent SPL at all levels for music, and in WinISD it shows a pretty flat frequency response. The box will sit on the passenger side of the trunk and have one amp mounted on top, and the other mounted on the side facing the driver.

I will be building a custom floor for the trunk so it can hold the additional weight of the drivers.

In addition I might be mounting the crossovers to the box, but they look quite nice in their current position so I am not too sure about moving them.

I may also move the distribution block and mount it on the sub box itself or very near for easy runs of power wire.

Any thoughts? I can make the box longer if needed, or even taller, I just dont know what recommended cubic feet I need for this.

EndersShadow

I realized last night that 20" is just the right size for both amps to be on the same side with no clearance. So by using the bigger baffels at both ends I have enough wiggle room to do that. The height is more than both need so they will be mounted vertically with the power cords, ground, etc coming in from holes in the MDF floor I am going to build. I am going to add a 1" offset for the amps so I can run the necessary RCA cords behind them, as well as allow for some additional airflow back there.

The only question is if I want to mount the crossovers on the box or not. I personally am leaning toward not and just leaving well enough alone :biggrin:

Now I just need the person selling the 12" TC sounds sub on AVSFORUM to respond telling me he has one, and hope the buyer for my current sub/box doesn't fall through, and I will have all of this for Christmas

P.S. finish on the sub box is going to be rhinoliner still, I had debated carpeting the whole thing, but the Rhinoliner not only will hold up to abuse, but also help seal any leaks in the box. The new trunk floor however will be carpeted.

EndersShadow

Going through more changes in the design but its pretty much the same concept as above. Here is my question.

Peak to Peak: If the rated peak to peak max is 3.5 does that mean the speaker cone can move 3.5 inches out from the box and 3.5 inches in the box, or is it simply 1/2 that or 1.75 inches each way?

EndersShadow

DSkip wrote: »

The latter.

Thanks!

This project is on hold till I sell my current sub/box since I need that cash to fund the purchase of the TC sounds sub. In addition the box is being redesigned with the intent to go ported out the side facing the drivers side. With that said box design is subject to change and I might revert back to my passive radiator design..