Box building material.

[Deeznutz]

This seems like a good topic. Just to add a twist to it, one thing does come to mind.

Now, depending on amount of power and the type of subwoofers used, does it really matter if you keep the set up simple like 2 12's on 800 to 1K watts?

Everything on earth has a resonant frequency, like someone pointed with enclosures-just stay above that. Adding fiberglass resin to help with diminishing the resonance, and it helped in that one db gain example is what I am going by.

To me, asking what would is best wood is a circular and loaded question. I see it as subwoofer motor, and power specific, because it's the motor and power that causes the resonance to occur in the first place. "What wood is best for said subwoofer/power combo? would be a better question". Any less and you're just building an expensive enclosure. Like building a house, depending on the load placed on the wood, the stiffness rating needs to be appropriate for the load. Why build an enclosure for a load that is below what is needed, only because it has stiffer rating?

Like BAA, he wants to use birch, but to use birch for 800W is a bit overkill to me just because he wants a stiff board.

Maybe I'm wrong in my thinking????

-Frank

[hispls]

This seems like a good topic. Just to add a twist to it, one thing does come to mind.

Now, depending on amount of power and the type of subwoofers used, does it really matter if you keep the set up simple like 2 12's on 800 to 1K watts?

Everything on earth has a resonant frequency, like someone pointed with enclosures-just stay above that. Adding fiberglass resin to help with diminishing the resonance, and it helped in that one db gain example is what I am going by.

To me, asking what would is best wood is a circular and loaded question. I see it as subwoofer motor, and power specific, because it's the motor and power that causes the resonance to occur in the first place. "What wood is best for said subwoofer/power combo? would be a better question". Any less and you're just building an expensive enclosure. Like building a house, depending on the load placed on the wood, the stiffness rating needs to be appropriate for the load. Why build an enclosure for a load that is below what is needed, only because it has stiffer rating?

Like BAA, he wants to use birch, but to use birch for 800W is a bit overkill to me just because he wants a stiff board.

Maybe I'm wrong in my thinking????

-Frank

Raising/lowering resonance of the box doesn't fix that as an issue. Build a box out of cardboard with a resonance of 1000hz and you won't get good sub-bass performance. In a subwoofer box ANY flex loses output. I forget the number but it's surprising how many dB even a 16th inch of flex will be... this goes for anything in the system.... hence the "extreme" vehicles that pour cement in the doors and use bullet proof glass and armor plating. Also along the topic of resonance, say you push your frequency up to 100hz, it's still resonate to the harmonics 50 and 25. (and 200, 400, etc.) The idea of a box is to separate the rear wave from the front wave. The two are 180 degrees out of phase and will cancel each other out.... so any bit of that back wave that leaves the box (though flexing, leaks, or out the port below tuning) takes away output.

Now certainly if you had a 200W system 5/8" wood would be fine and probably just about anything would do the job. There's certainly a point where the flex is acceptable vs the cost/weight and even as certainly a point in every application where adding more/stiffer material gains nothing.

If you google search for "baltic birch" a lot of the benefit of using it is cosmetic. How much more rigid is it than cheaper ply? than particle board? etc.? Certainly it's better by every measure that will interest us, but can anybody quantify this in foot pounds or something else we can use for direct comparison? I'd suggest we need either some hard data for comparison or some A/B testing with different box materials. My biggest bitch about this is that everybody "knows" what's best but nobody has done any testing or can show any technical data to prove anything.

[Broke_Audio_Addict]

I say build with ever you want if it's not mine I don't really care what you use.

I'm using real birch plywood because this will be in the bed of a truck and you never know what could happen, if mdf gets wet say bye bye to enclosure.

Cheap plywood is just like any cheap version of anything, it's crap it serves a purpose but building enclosures isn't one of say the cheap stuff should be used for because of all the reasons audiofanaticz pointed out.

And double layers for strength because I believe anything worth doing is worth doing right the first time.

Ive built test enclosures out of osb but that's about all I would personally use it for.

go buy some of these woods and test them yourself.

Part of the advantech's strength comes from the fact that it can flex which means it isn't very rigid

[Broke_Audio_Addict]

And before you say its rigid and doesn't flex

[MotorCityFats13]

was the sheet on the right normal mdf subfloor wood... it was the only one that matched the color of the wood I been using since 1995

[Deeznutz]

I say it goes back to the manufacturer of the subwoofer you plan on using. They make prototypes and hand them over to bassheads to torture test them for a given time frame. Find out what they used to make the enclosure they tested the subwoofer with. Or what works best for their product.

People who say this works and that works......it's because it worked for them. Taking their advise as gospel only to use "their theory" on a different brand?

Hard to make a generalized statement on which wood is best based on that.

Stiffness, rigidity, flex. Remember all wood flexes. lol. Bracing "x" few inches helps minimize it. What's the golden rule for panel runs before adding a brace?

I was about to bring up this topic since Devin's 4th order will be powered by @ 1800W.

BAA brought up a good point about doubling up on the wall thickness. Ram's design has the top and bottom panels as one panel thick. All other panels are double walled.

I should have enough room to double the top and bottom panels to minimize panel "flex".

See, now you have me saying it!!!

-Frank

[Broke_Audio_Addict]

Rigidity would determine how much the wood resist flexing but yes all wood is going to flex some amount.

Go cut some strips of various types of wood and test them, it's not hard.

Surely someone here has the means to do so.

[hispls]

And before you say its rigid and doesn't flex

Care to try that test with a sheet of MDF or plywood? I'd wager just about any 3/4" manufactured lumber would flex or break with a full grown man bouncing up and down on a sheet like that.

Speaking of which. Check out this "bendy" MDF. Flared ports or interesting shaped boxes? http://www.bendymdf.co.uk/introduction.htm

[dsw422]

And before you say its rigid and doesn't flex

http://youtu.be/3NO2FqblmOs

Care to try that test with a sheet of MDF or plywood? I'd wager just about any 3/4" manufactured lumber would flex or break with a full grown man bouncing up and down on a sheet like that.

Speaking of which. Check out this "bendy" MDF. Flared ports or interesting shaped boxes? http://www.bendymdf.co.uk/introduction.htm

Link don't work...

Also.. I don't see the point in testing the bend strength/resistance in a full sheet.. under no circumstances should a box use a full sheet with no bracing..

if you want test out these panels.I say test with smaller pieces, maybe 12"x12"... then build identical enclosures out of your panels your testing.. and measure difference in output between your test boxes.. weight them too!!..

I'm assuming the test panels will be, advantech, mdf, real 11 ply birch, and maybe others..

EDIT: I'm assuming this is like the mdf u linked..

http://www.amazon.com/Neatform-Bendy-MDF-Sheet/dp/B001DT4TVS

[Broke_Audio_Addict]

And before you say its rigid and doesn't flex

http://youtu.be/3NO2FqblmOs

Care to try that test with a sheet of MDF or plywood? I'd wager just about any 3/4" manufactured lumber would flex or break with a full grown man bouncing up and down on a sheet like that.

Speaking of which. Check out this "bendy" MDF. Flared ports or interesting shaped boxes? http://www.bendymdf.co.uk/introduction.htm

If you say so.

What you use is not the end all be all its just what you choose to use.

Just throwing this out there, all the extremely loud builds on here or most places for that matter are built from mdf or plywood, you aren't about to change the game with fucking osb.

If my goal was to get loud i would take my advice from the pros, just sayin.