Another sub box(might keep this one) [Archive]

Notladstyle

03-30-2006, 09:20 PM

I wasted two and a half hours building a single 12" box and when I was all done it sounded perfect.

Lessons learned:
- equal distances to walls makes for bad sound
- sound deadener really helps
- slotted ports are easier to build
- 36hz is the perfect tunig frequency for a sedan

Liquid nail > * ----- I used the weatherproof one cuz it was only 60 cents more

1x12.5" slot is the same thing as a 4" diameter port
http://notladstyle.com/post/b1.jpg

Super secret sound deadener (hint: it costs like 9$ for 100 sq ft and is cusiony and waterproof doubles as thermal insulation in its original aplication)

http://notladstyle.com/post/b2.jpg

Same material triples as a wonderfull gasket for air tightness and doesnt lose compression like foam/caulk do.
http://notladstyle.com/post/b3.jpg

Obsessive soldering

http://notladstyle.com/post/b4.jpg

Obsessive sealing even around the terminals

http://notladstyle.com/post/b5.jpg

sounds better than the box it replaced... BTW couldnt use the 25 degree angle because my amp is gonna be mounted on the side of the seat and the only way to modify the settings will be the passthrough. But I was thinking maybe I would put two removable triangles on either side to seal the sub against the seat...
http://notladstyle.com/post/b6.jpg

weird facts - the sub manual calls for 1.75cuft ported to 41hz while the thelie small parameters optimize at 2.15cuft ported to 38hz

I built to 1.95gross, 1.80cuft net ported to 36hz (aproximately) because I like low bass.

Tomorrow: the fun of carpeting and amp rack construction.

GradeA_TireFryer

03-30-2006, 10:10 PM

my experience that particle board is good - but mdf is much denser and cuts, glues, and nails, screws alot easier....

Notladstyle

03-30-2006, 11:10 PM

my experience that particle board is good - but mdf is much denser and cuts, glues, and nails, screws alot easier....

I know & agree.. but the closest MDF is at home depot and thats like 25 minutes away and when you build a new sub box every week you dont have time for that. plus the longest side is only 24" and I cross braced it. I doubt a ~400wrms amp will be able flex enough to make me complain.

TBSpyder

03-31-2006, 01:32 AM

You know liquid nails breaks down over time? And for such a soldering freak....I'm surprised to see the wire nuts.... ;)

Notladstyle

03-31-2006, 03:35 AM

You know liquid nails breaks down over time? And for such a soldering freak....I'm surprised to see the wire nuts.... ;)

it will last the week it will take me to get tired of the box being tuned so low. My rock music sounds like gangsta rap and my gangsta rap sounds like an earthquake...

plus it doesnt break down any slower than wood glue and it about 100x as strong.

and I forgot to groove & glue the wire in on the top panel because I was being rushed by my damn wife.

TJElite

03-31-2006, 12:18 PM

Couple notes:

Your 'obsessively sealed box' isnt. MDF and particle board are very, very, porus. We were moving some sheets with a vacuum loader once, and you could pick up 3 or 4 sheets by putting vacuum to the top one. Vaccum at sea level can not exceed the equivalent of 14.7 psi, so your sub is capable of pushing air through it. You really should seal the box with resin or varnish. Carpet and glue won't to it. Overkill? Maybe, but its easy and cheap, and leakage will affect the overall Q, even in a ported box. I do like the gasket, though...a step many people leave out.

I've found a new wonder adhesive for box building. Its called PL Premium Polyurethane Construction Adhesive. Its like $3 a tube (big caulk sized tube) at Home Depot. This stuff will stick anything to anything, and guarantees that the glue will last longer than whatever you are sticking together.

I've got to echo the thumbs down on the wire nuts.

Just curious what you used to calculate the ideal box. I use Bassbox, and it often disagrees with the manufacturers specs. Usually, though, if you plot the manufacturers spec against the bassbox, there isn't much difference, and its usually based on what is each system considers 'ideal'. Bassbox tends to want smooth curves and low F3, while manufacturers often take into account the transfer function of the car, and give up F3 in favor of a hump in the 50-80hz range.

You have hit on another issue with ported boxes...cars have resonant peaks, that can play hell with tuning. When you're down here on the 8th, maybe we'll throw a 'test box' in your car...like a 10 in a small sealed box, for example, and run a frequency sweep to find the resonant frequency range of your car, and define the transfer function. This is definitely overkill, but somehow, I think you'd like to have that data :-)

Toby

GradeA_TireFryer

03-31-2006, 01:13 PM

wires nuts, i was going to let that go.

Bumpin Expo

03-31-2006, 01:19 PM

Jesus christ you people go way over the top when building boxes. What ever happened to the 3/4" MDF wood held together with liquid nails and screw sealed with silicone.

TBSpyder

03-31-2006, 02:29 PM

A true freak would fiberglass the inside of the box. ;)

Notladstyle

03-31-2006, 02:46 PM

A true freak would fiberglass the inside of the box. ;)

You guys are seriously swayed by urban myths or peer pressure to make such a broad claim as plywood is "pourous" can anyone happen to supply the presure/release decay formula for plywood compared to MDF? I cant either but with common sense I am assure you that a single 250wrms 12" in a box < 2cu ft will not leak any significant amount of air though the "pourous" wood. Toby I would expect more from you :roll:

The walls are coated in insulation & LN, thats the most effort I'm willing to put forth until I find the perfect box.

The res freq or my car is 58hz with the seats in.

The lug nuts make it incredibly easy to remove the box when I have an install (unlike you shop owners I have to load every tool I'll need into my car alone with an inverter to run them) and again, at the low power output of my amp & sub there will be no significant leaking there either.

I use a TI-83 with lots of formulas programmed into it for box calculations and a little of the old noggin to put it all together. I used to use winISD but it disconnected me from my brain so I dont any more.

MDF is close to 30% heavier than plywood and since the box is sitting right over my rear wheels that doesnt make me happy.

I might give the polyurethane glue a try but I like quick and non-toxic fumes so I can throw it into my car faster which I doubt that can offer.

Bumpin Expo - I forgot the silicone so I just doubled up on LQN

but really I have to point out again that "porus" wood only become porous over a long period of time or under extreem air pressure.

TJElite

03-31-2006, 03:10 PM

You guys are seriously swayed by urban myths or peer pressure to make such a broad claim as plywood is "pourous" can anyone happen to supply the presure/release decay formula for plywood compared to MDF? I cant either but with common sense I am assure you that a single 250wrms 12" in a box < 2cu ft will not leak any significant amount of air though the "pourous" wood. Toby I would expect more from you :roll:

Again, I'm speaking from first hand knowledge. A vacuum on the top sheet 'penetrated' through 3 more sheets. That's only 14.7 psi, tops...probably less. So, it is porus. Now how much will it leak...can't say. I was just responding to your 'obsessivley sealed' comment. How long does putting a coat of varnish or resin on the inside take? How much does it cost? I can see not doing it on a trial box, but on the finished product, what can it hurt? Especially for someone as obsessed with perfection as you. I would expect more from you :roll:

MDF is close to 30% heavier than plywood and since the box is sitting right over my rear wheels that doesnt make me happy.

I might give the polyurethane glue a try but I like quick and non-toxic fumes so I can throw it into my car faster which I doubt that can offer.

Fortunately, you didn't actually use plywood, or that would open up a whole new issue. What you have in your picture is particle board. 30% seems high, but how much weight are we talking...an extra 3-5 lbs?

The PU dries fairly quickly...on par with RTV, and fumes are all but nonexistant.

but really I have to point out again that "porus" wood only become porous over a long period of time or under extreem air pressure.

And I again have to point out that you are wrong. Unless a long period of time is nearly instantly, and extreme air pressure is less than 14.7 psi.

Toby

TJElite

03-31-2006, 03:11 PM

Jesus christ you people go way over the top when building boxes. What ever happened to the 3/4" MDF wood held together with liquid nails and screw sealed with silicone.

Same thing that happened to powered EQ's...we got smarter.

Toby

TBSpyder

03-31-2006, 06:30 PM

You put forth the extra effort to solder all your connections...you're just counteracting yourself when you take shortcuts elsewhere.

There may be alot of little nit-picky things in car audio, but I can assure you when you put all those little things together, they add up in a big way. I've seen boxes made out of concrete. :D

TJElite

03-31-2006, 06:38 PM

I've seen boxes made out of concrete. :D

I actually judged a car with a concrete box at Daytona, back about 91, or so. We all thought the guy was nuts, until we heard it. Box coloration is one of those things you can't put your finger on, until its just not there at all.

Toby

TJElite

03-31-2006, 06:40 PM

You put forth the extra effort to solder all your connections...you're just counteracting yourself when you take shortcuts elsewhere.

This is where I was going. You are a really smart guy, who knows lots more about car audio than many other people. I was just trying to throw out a couple more cheap, easy ideas, that can't hurt, and might actually help.

Toby

Notladstyle

03-31-2006, 06:44 PM

Again, I'm speaking from first hand knowledge. A vacuum on the top sheet 'penetrated' through 3 more sheets. That's only 14.7 psi, tops...probably less. So, it is porus. Now how much will it leak...can't say. I was just responding to your 'obsessivley sealed' comment. How long does putting a coat of varnish or resin on the inside take? How much does it cost? I can see not doing it on a trial box, but on the finished product, what can it hurt? Especially for someone as obsessed with perfection as you. I would expect more from you :roll:

Fortunately, you didn't actually use plywood, or that would open up a whole new issue. What you have in your picture is particle board. 30% seems high, but how much weight are we talking...an extra 3-5 lbs?

The PU dries fairly quickly...on par with RTV, and fumes are all but nonexistant.

And I again have to point out that you are wrong. Unless a long period of time is nearly instantly, and extreme air pressure is less than 14.7 psi.

Toby

I must see this porus demonstration - but I think im confused as to the difference between plywood and particle board, im an engineer not a carpenter :roll: So is the porus comment towards particle board or plywood?

Am I wrong or did I just get the name of the wood wrong because I am certain that the wood I used in the above pics will hold well over 15psi with < 1% seepage. Can we destroy one of my old boxed at the meet and test it out?

TJElite

03-31-2006, 07:52 PM

I must see this porus demonstration - but I think im confused as to the difference between plywood and particle board, im an engineer not a carpenter :roll: So is the porus comment towards particle board or plywood?

Am I wrong or did I just get the name of the wood wrong because I am certain that the wood I used in the above pics will hold well over 15psi with < 1% seepage. Can we destroy one of my old boxed at the meet and test it out?

I will try to demonstrate the porus experiment at the meet.

As for the wood...what you used is typically called particle board. It is basically glued together sawdust. Plywood is made up of several layers. If you look at the edge, you'll see them...looks like one of those crispy wafer cookies. It will also have a visable grain, and sometimes knots, etc. MDF is similar to partical board, except that it is made of much finer particles, or fibers, as the name, medium density fiberboard, suggests.

Plywood makes a crappy box because it is not as dense, and sometimes delaminates. Particle board is more dense, but not as dense as MDF.

My porus comment was aimed at MDF...I would think that particle board is similar, and plywood might be less porus. Not sure the seepage %, but it might be (probably is) minimal. I'll see if I can work up a couple of tests.

Again, all I was doing was offering another detail, to an obviously detail oriented person.

Toby

TBSpyder

03-31-2006, 08:11 PM

You really need some HDF. :)

Notladstyle

03-31-2006, 09:40 PM

You really need some HDF. :)

a 24x48 board is like 18$ =/

URBANRCR

04-01-2006, 01:42 AM

it looks good to me way better than i could do.

Notladstyle

04-01-2006, 01:45 AM

it looks good to me way better than i could do.

I dont think anyone is against the craftmanship, its my choice in materials that seems to be the main topic of conversation. Thanks for the props tho ;)

Notladstyle

04-01-2006, 01:53 AM

You know liquid nails breaks down over time?

OK so since I was surprised to find that my one stop adhesive for all permanent aplications might break down over time, I went back to lowes and asked the contruction manager some questions(I pretended I was writing a paper) and he told me the following:

Liquid nail is basicly a blend of putty and hardening resin. The standard liquid nail will hold up in anything except constant submersion in water and has a 2 year warranty. The construction liquid nail(the one I bought) is made to be water/weather proof and is backed by a 10 year warranty against failure when properly prepped and applied - it must be a 1/4" bead for every cuft and must be allowed to prep for 36 hours before movement.

I still wouldnt use anything other than silicon II for seam seals on a permanent project but it is good to know that this stuff will hold for at least a week.

TJElite

04-01-2006, 10:54 AM

a 24x48 board is like 18$ =/

I buy 4'x8' sheets of 3/4 MDF at Lowes or HD for like $25. Not sure how much a similar sheet of particle would cost, but even if it was half, a box worth is not that much difference, and is well worth it. I'd actually like to use HDF, but the only source I know for that is a cabinet supply place way down in south st. pete. If anyone knows of a closer to Oldsmar source, let me know.

For really big boxes, we use double 3/4". I use wood glue and an air nailer to hold them together, and then use the PU construction adhesive on the joints. The, we slap a coat of polyester resin on the inside. Overkill? Maybe, but the extra time and money is fairly small, and I feel the payback is worth it.

This is for our custom boxes, which not everyone can afford. We also sell prefab boxes, which are particle board and silicone, covered in carpet. These boxes work just fine for most people. But, when someone is willing to pay me to design and build them a box, I like to put the extra effort in.

I think your box is probably fine, especially for a 'test box'. When you finally get the design finalized, though, I think you should put the extra effort into it. Especially since you care about details.

Toby

TBSpyder

04-01-2006, 01:00 PM

OK so since I was surprised to find that my one stop adhesive for all permanent aplications might break down over time, I went back to lowes and asked the contruction manager some questions(I pretended I was writing a paper) and he told me the following:

Liquid nail is basicly a blend of putty and hardening resin. The standard liquid nail will hold up in anything except constant submersion in water and has a 2 year warranty. The construction liquid nail(the one I bought) is made to be water/weather proof and is backed by a 10 year warranty against failure when properly prepped and applied - it must be a 1/4" bead for every cuft and must be allowed to prep for 36 hours before movement.

I still wouldnt use anything other than silicon II for seam seals on a permanent project but it is good to know that this stuff will hold for at least a week.

Is that taking into consideration the increased pressure in a sub box enviroment? I'm just going on what I've been told by other installers and what I've seen first hand. I use to use the stuff all the time. I've seen several boxes that could be kicked apart though, which were about a year old, and a couple overhead monitors which were installed with liquid nails (not done by myself) which fell within a 1-2 year period.

I don't see how they could back that warranty, there's just too many variables (ie, differing weigh, pressure, materials, etc) and it would be almost impossible to prove, let alone proving the prep and application procedures. And then, even if they did warranty something, what are they going to do? Give you another tube and tell you to try again? Replace whatever it is that came apart and was possibly damaged in the process?

Notladstyle

04-01-2006, 01:54 PM

Is that taking into consideration the increased pressure in a sub box enviroment? I'm just going on what I've been told by other installers and what I've seen first hand. I use to use the stuff all the time. I've seen several boxes that could be kicked apart though, which were about a year old, and a couple overhead monitors which were installed with liquid nails (not done by myself) which fell within a 1-2 year period.

I don't see how they could back that warranty, there's just too many variables (ie, differing weigh, pressure, materials, etc) and it would be almost impossible to prove, let alone proving the prep and application procedures. And then, even if they did warranty something, what are they going to do? Give you another tube and tell you to try again? Replace whatever it is that came apart and was possibly damaged in the process?

didnt ask all those Qs but for the overhead monitor issue there would usually be no prep time because 1) installs are in a hurry to finish and 2)its mounted directly to the surface so gravity takes its toll immediately.

It's used constantly in home construction on trim moldings, ceilng tiling, and drywall base and I havent seen many houses fall down lately. I doubt its the be all end to end for adhesives but horror stories may have been exadurated and installation steps may have been skipped. As for hte box being kicked apart, the wood & nails will hold through more than that without any glue at all so im leaning towards either water damage or wood failure over glue failure.

Notladstyle

04-01-2006, 01:58 PM

I buy 4'x8' sheets of 3/4 MDF at Lowes or HD for like $25. Not sure how much a similar sheet of particle would cost, but even if it was half, a box worth is not that much difference, and is well worth it. I'd actually like to use HDF, but the only source I know for that is a cabinet supply place way down in south st. pete. If anyone knows of a closer to Oldsmar source, let me know.

For really big boxes, we use double 3/4". I use wood glue and an air nailer to hold them together, and then use the PU construction adhesive on the joints. The, we slap a coat of polyester resin on the inside. Overkill? Maybe, but the extra time and money is fairly small, and I feel the payback is worth it.

This is for our custom boxes, which not everyone can afford. We also sell prefab boxes, which are particle board and silicone, covered in carpet. These boxes work just fine for most people. But, when someone is willing to pay me to design and build them a box, I like to put the extra effort in.

I think your box is probably fine, especially for a 'test box'. When you finally get the design finalized, though, I think you should put the extra effort into it. Especially since you care about details.

Toby

Lowes in zephyhills doesnt have 2x4 or 4x8 shept of MDF I dont know why.

24 x 48 particle board is $4 at lowes... used to be 2.50 but they caught on when I bought 20 sheets and loaded them into my 4door.

prefab boxes use woodglue which is tehsuxx0r for anything other than urinating in.

I will definitley put the extra effort into a box that sounds good... I may just fiberglass the walls and skip wood entirely.

rys

04-03-2006, 03:25 PM

do you build these for sale?

TJElite

04-03-2006, 07:12 PM

do you build these for sale?

Who are you asking? There are several people on this thread that build boxes.

Toby

rys

04-03-2006, 08:43 PM

Who are you asking? There are several people on this thread that build boxes.

Toby
I was asking the thread starter but I guess anyone, lol I made a WTB thread in the for sale section.

Notladstyle

04-04-2006, 12:59 AM

I was asking the thread starter but I guess anyone, lol I made a WTB thread in the for sale section.

I build boxes for for beer :D the drive to my house in zephyrhills is usually more expensive ;)

But yeah bring me wood on a day im free and I'll build you one for practice... just make sure you bring 3/4" MDF and your car so we can measure it.

rys

04-04-2006, 10:48 AM

I build boxes for for beer :D the drive to my house in zephyrhills is usually more expensive ;)

But yeah bring me wood on a day im free and I'll build you one for practice... just make sure you bring 3/4" MDF and your car so we can measure it.
rofl this is my kind of man

93ex

04-04-2006, 12:00 PM

Wood glue actually seeps into the pores of the wood, I've found liquid nails really just is a surface bond. I'll use CA glue to hold a box together while the wood glue sets. I've broken apart a liquid nails bond, vs a wood glue bond, and the wood glue takes a LOT more wood with it.

Yeah Liquid nails holds up trim moldings and chair rails etc etc, and they dont fall down. Of course they are in a climate controlled low humidity enviroment, not in a car that during summer can hit 120 during the day and 60 at night.

GradeA_TireFryer

04-04-2006, 12:15 PM

TBSpyder

04-04-2006, 12:43 PM

I Will Have To Agree - Use Tight Bond Ii Wood Glue On All Your Seams, Let It Dry (about A Hour)- Then Use Silicon In All The Corners,
I Like The Idea Of The Using Fiber Glass Resign To Seal The Inside Air Tight
(anyone Know What Product Exactly To Use For That?)

I've always used just a standard resin, just don't mix it too hot or it will chip off the mdf too easily.

And yeah, good point, the boxes I've pulled apart which used wood glue usually took chunks of the wood with it...however the liquid nailed boxes usually break away cleanly.

Notladstyle

04-04-2006, 03:26 PM

hhmf wood glue never held a hammer to the celing in a TV commercial. Ill stick with my waterproof weather proof liquid nail and good ols fashioned silicone.

TJElite

04-04-2006, 04:36 PM

I Will Have To Agree - Use Tight Bond Ii Wood Glue On All Your Seams, Let It Dry (about A Hour)- Then Use Silicon In All The Corners,
I Like The Idea Of The Using Fiber Glass Resign To Seal The Inside Air Tight
(anyone Know What Product Exactly To Use For That?)

I use generic polyester resin. Best deal I've found is at us composites www.uscomposites.com (http://www.uscomposites.com). I use their EB grade general purpose. its down in the $19 a gallon range. They have a better price to the general public than I can get from the distributors. They also have all kinds of cool stuff like fiberglass cloth and mat is lots of weights, milled fibers, mold releases, etc.

Toby

TJElite

04-04-2006, 04:40 PM

hhmf wood glue never held a hammer to the celing in a TV commercial. Ill stick with my waterproof weather proof liquid nail and good ols fashioned silicone.

FWIW, particle board and mdf is basically made of wood glue and sawdust.

I also prefer the penetrating nature of wood glue.

Anyone tried the new gorilla glues? They are basically an isocyanate that reacts with moisture in the air to make polyurethane. It looks like it might have the penetration of wood glue, but lots more durable. Once its dried, its basically even solvent proof.

Toby

93ex

04-04-2006, 04:40 PM

hhmf wood glue never held a hammer to the celing in a TV commercial. Ill stick with my waterproof weather proof liquid nail and good ols fashioned silicone.

I built my entire last box with CA glue. I'd rank it over either for holding a hammer to the celing.

PS of course I siliconed the inside.

GradeA_TireFryer

04-04-2006, 05:39 PM

I Have Used The Gorilla Glues - Really No Opion, Would Rather Use Tighbond Ii Wood Glue! - Cleans Up With Water Before It Dries

djgizmo

04-05-2006, 12:55 AM

djgizmo

04-05-2006, 01:01 AM

PS. Dalton, wtf happened with my idea. lol, oh well, guess it was ditched out the window.

TJElite

04-05-2006, 11:14 AM

So you're saying for some custom boxes, they are 1.5 inches thick? Now I DEFFINATELY need to come to the meet. My box is 1.25 inches thick (custom box from years ago from a guy up north) Love it. Damn thing ways a ton though.

Yep. The box in my caprice is about 9 cu. ft gross, double 3/4 MDF. Holds two Crossfire XT215's.

When I put this thing in, and added the 2600 RMS watts of amps, and the two big stinger batteries, I had to pull the lowering springs out of the back and replace them with heavy duty truck springs...to keep the car level!! There's also probably 150 lbs of dynamat in it, as well. Not exactly a speed demon, but it cruises smooth and quiet, except for the stereo, of course :D

Toby