Any problems puttin sub boxes in this?

[BadassBlaze]

I was toying around with inventor and came up with a lockable storage box. Anyways, I was wondering if I would have any problems with putting the MDF sub boxes inside this lock box? You can see where I have holes cut out so the subs will be able to play thru, hence they will be downfiring subs. The box will sit up off the floor a bit, so the subs hittin the ground will not be a problem. I just don't know if I would have a problem with the boxes making some weird resonance being inside the diamond plate storage box. So far my plan for the boxes is sealed, but I could make the boxes bigger and port them, which also is a thought. The ports would exit out of the lock box firing towards the rear seat. Each sub will be in a seperate box. Any help would be greatly appreciated

 

[dhcomp]

IF its MDF inside that, should be fine. I'd caulk the hell out of the mating surface between mdf and metal though.

 

[BadassBlaze]

Oh yeah...definately will caulk between the metal and mdf, hopefully between that and it being screwed down firmly it wouldnt rattle. I'm hopin chevyin will chime in, it seems like he has quite a bit of knowledge in the audio area

 

[chevyin]

Well, generally metal boxes for speakers are a no-no. Like you said, concerns over resonances. But, you are adding a new twist, mdf inside the metal. (good thinking btw)

Honestly, I dont know how well it'll work. My guess... it will work just fine. Fasten the wooden enclosures to the metal securely (bolted in place), this will couple the boxes to the metal. That should eliminate any concerns over wood-to-metal noises. The only concern that will leave is will the metal storage box itself vibrate too much. Judging by your drawing, the box has small sides, alot of angles, and two interior braces... excellent for rigidty. Again my best guess would be it will work just fine.

Be sure the holes are plenty large enough, and that the speakers fire directly through them. You do not want the speakers to fire into an air space, then need to escape out through the holes. This could cause a quasi-bandpass effect (like adding another enclosure to modify the sound). But it sounds like you already have that planned out.

All in all, I really like the idea. let me/us know if there's anything we can do to help, and show us some pics when you do it.

BTW... aint Inventor nice?

 

[BadassBlaze]

Thanks for chimin in... Yeah the storage box isnt super big, but it will take up almost all of the cargo area. Right now it is at 17 inches tall without a lid on it. The box will be up off the floor about an inch (i believe...), and the holes in the storage box will actually be cut to the outside diameter of the sub so the entire sub can fit thru it, so it will fire directly out of the storage box, and avoid what you were talking about. I definately thought about the effect of it firing while still recessed inside the storage box...while interesting, i'm sure i wouldnt like the sound lol, it would prolly be really boomy, like a bandpass...like you were sayin lol. But thanks for the info/thoughts. I'm in the planning stages right now, and its lookin like the date i start on the blazer is gettin pushed back, but i will keep ya'll updated. I really anxious to see how the storage box turns out.

And yes....Inventor is really nice...to bad I'm not an expert with it, as seen by the drawings lol

 

[chevyin]

Thanks for chimin in... Yeah the storage box isnt super big, but it will take up almost all of the cargo area. Right now it is at 17 inches tall without a lid on it. The box will be up off the floor about an inch (i believe...), and the holes in the storage box will actually be cut to the outside diameter of the sub so the entire sub can fit thru it, so it will fire directly out of the storage box, and avoid what you were talking about. I definately thought about the effect of it firing while still recessed inside the storage box...while interesting, i'm sure i wouldnt like the sound lol, it would prolly be really boomy, like a bandpass...like you were sayin lol. But thanks for the info/thoughts. I'm in the planning stages right now, and its lookin like the date i start on the blazer is gettin pushed back, but i will keep ya'll updated. I really anxious to see how the storage box turns out.

And yes....Inventor is really nice...to bad I'm not an expert with it, as seen by the drawings lol

Your drawing looks fine to me.

Honestly, it sounds like you already had all the bases covered and didnt really even need my input. lol

Laters.

 

[BadassBlaze]

lol, i wanted the thoughts on someone more knowledgeable than me. This isnt my first stereo, nor the first sub boxes I've made. I did alot of research and learning last year when I was into building HT speakers, but never did built alot...I built a few bookshelf speakers that were pretty impressive, but I know they were far from perfect as far as freq response, but for the price they sounded alot better than anything you could get at the local worst buy or circuit ****ty...anyways, hopefully everything will work out and i can start on it mid-late may

 

[Hazy]

i would maybe resin it (3-4 coats) so thats your box and then port it and it would hit hard. MDF it okay but usually i resin the inside too because fiberglass does resinate. for yours i would skip the mdf all together execpt for where you need to mount a ring. then just resin it, and fleece where needed.

 

[BadassBlaze]

I think it'd be far easier for me to just make them out of mdf...I dont see how just putting resin on the insde of a steel lockbox is that great of an enclosure for a sub, plus I still have to make a top for the box out of mdf....I'm prolly gonna stick with mdf cause I could knock out 2 boxes in a day no problem

 

[Hazy]

actually resin is good cause it doesn't resinate like mdf so the sub will hit better. and you will need a wood ring. there is always 100 + ways to do 1 job. so take it or leave it. as far as being easier thats a toss up cause if your good at fiberglass then it is fast and easy.

 

[chevyin]

actually resin is good cause it doesn't resinate like mdf so the sub will hit better. and you will need a wood ring. there is always 100 + ways to do 1 job. so take it or leave it. as far as being easier thats a toss up cause if your good at fiberglass then it is fast and easy.

MDF is actually quite dead, that's why it's used. I don't know why you think it has some sort of problem with resonating.

There's 2 ways to avoid enclosure resonation, build it so massive its tuning frequency is below the operating range of the system, or build it so stiff its resonant frequency is above the operating range. MDF, by the nature of its density, tends to have lower res freq, where as the stiffening property of fiberglass tends to have higher. Fiberglass enclosures are actually more susceptable to resonating than are mdf boxes.

Either one, when properly braced, wont flex/ring/resonate. That small of boxes, with relatively low power, he needs not worry about such things.

I understand where you are coming from, resining the inside of the steel box to seal it and stiffen it. It would gain internal enclosure volume, but there are several reasons why I wouldn't do it and I think I'll just leave it at that (tired tonight).

 

[BadassBlaze]

Thats kinda what I thought is that there was really no problem with mdf. I always thought that fiberglass was used to be showy. I know that it does make nice enclosures, but it was always used to do more showy enclosures that were painted and had curves and stuff

 

[chevyin]

Thats kinda what I thought is that there was really no problem with mdf. I always thought that fiberglass was used to be showy. I know that it does make nice enclosures, but it was always used to do more showy enclosures that were painted and had curves and stuff

Fiberglass enclosures are also excellent for maximizing space. You can build a fiberglass enclosure that contours your interior shape eprfectly, utilizing every availble cubic inch, where as a square wooden blox is much less efficient. Dont get me wrong, fiberglass has TONS of positive uses. Its just not the end-all be-all material for every situation.

 

[Hazy]

agree