mdf

stevdart wrote: You answer it then.

I think I need to you guys are in lala land. Okay rather than address ALL the retarded statements in this thread one by one, I'll just tackle the original question head on. MATTERS: Rigidity Air-permeability DOES NOT MATTER: Thickness Porousness (....air in wood stevdart?) Density MDF is VERY strong. It isn't weak beacause it 'chips and cracks' whoever said that I'll spare you quotes... this demonstrates a fundemental lack of understanding of architecture and materials... Take concrete for instance... VERY HIGH compression strength... Not so much TENSILE strength... which is why you can drop a concrete slab two feet and shatter it.... same with MDF... But try and compress concrete eh? Ya think standing on it will produce the same result? This characteristic is why we line our roadways and buildings with steel cables... they provide that tensile strength. On the other hand, in car, we don't need that sort of strength. Your box should be bolted to your car nessecitating it only to withstand the *compression* waves from the speaker itself... which.. in all blindness to the design on the speaker box, are, obviously, uniform in dispersion into the enclsoure proper. So with MDF... its rigidity.. particularly in subwoofer-box sized applications... makes it ideal for a speaker application... HDF will simply serve you more of the same. In this case however, more isn't going to be any better, its just more. You will simply be adding another 1/3 or so to the weight of your box which is already quite hefty.. and then sticking it in your car. The idea that it is "better" here is akin to using 8-gauge speaker wire .... it doesn't functionally do anything 12-gauge doesn't, but theoretically in the numbers somewhere there's a gain. In this case it would probably be measured in microns. It would take a laser to measure the improvement. It's the whole 'density' thing. We all use dense materials when making a sub-box, but not because they are dense, but because dense materials are inherently *rigid* ... the ultimate goal isn't to "absorb" or "reflect" or "suspend" or whatever the ultimate goal is to have no flexing of the enclosure while the speaker plays ensuring linaerity of cone movement.... In fact, I go a different route than most people.... I kinda dread those 75lb workout boxes that 3/4 MDF tends to produce so I use 1/2MDF and go hefty with fiberglass resin on the inside. The boxes are *much* lighter and at least *I* can't hear a different between those and much, much heftier 3/4" variants."I'm finished!" - Daniel Plainview

ok thank for your input sedate that was very helpful. but you could of speired to remark about what i said. im only trying to give an opinion, and i asked for help from somebody. did i say i was right noooo. i have work and do work with mdf and it dos chip and crack it chips when you cut it and it cracks and little cunks come off if you bump into stuff or if you acsidently scrape it on something. and im kind of pisset off that you called the statments people make retarded we are haveing a intelectuale argument we arent trying to put people down like somebody. and you also tryed put down stev. i realy dont like people that are smart but cant be polite and correct people in the right way. and i respeckd stevdart for his input and take it into acount and dayhon to they both now what they are talking about. and i know that mdf is strong. and i do know what im talking about in most cases and one of these days will correct you.Want to know some good equipment- JL,Adire Audio,Mcintosh,Brax,Helix,Eclipse,JBL,RE,Dimoand Audio,Zapco, pritty much anything DYhon,Forbidden recommend

On the12volt you give some info and you get in

geepherder wrote: Sedate, just a slight correction- you stated that thickness doesn't matter.  That's way too broad of a statement.  Yes, many of us have built boxes out of 1/2 inch as well.  But who hasn't seen a box that was ruined by using a material that's too weak, or thin?  I understand there are different ways to the same mean, but what you said could be interpreted that using a single layer of 1/4 inch would be okay to build a ported box for a couple 13w7's run by a 1000/1 a piece.  I'm sure that's not what you meant, but you shouldn't make such bold generalizations. You're right that the goal is to minimize flexing.

Exactly what I was thinking.Tell the Snap-On guy I'm not here!

see they were polite in corecting you thanks guys AaronWant to know some good equipment- JL,Adire Audio,Mcintosh,Brax,Helix,Eclipse,JBL,RE,Dimoand Audio,Zapco, pritty much anything DYhon,Forbidden recommend

On the12volt you give some info and you get in

sedate wrote:

[ I think I need to you guys are in lala land.

Okay rather than address ALL the retarded statements in this thread one by one.]

yes i am one of those retards in lala land!    ever been there?

I sniff resinTell the Snap-On guy I'm not here!

hahaha 5150azn. oooooooooyyyyyyyaaaaaaa Want to know some good equipment- JL,Adire Audio,Mcintosh,Brax,Helix,Eclipse,JBL,RE,Dimoand Audio,Zapco, pritty much anything DYhon,Forbidden recommend

On the12volt you give some info and you get in

I have to side with sedate. Thickness DOES NOT MATTER. You can build an enclosure with 1/4 inch material, but what kind of material are we referring to? He never said you could use 1/4 inch MDF, and get acceptable sonic characteristics, did he? Truly, the thickness does not matter, the MATERIAL matters. An infinitely rigid material could be infinitely thin, and still be perfect for an enclosure, right? (I'll save some of you the thought process.) Yes. And what is determined by the material? (let's see who's paying attention) That's right, class - rigidity and porosity. I have built enclosures with welded 1/4 inch aluminum plate, that rang like a bell at higher frequencies, but it WAS rigid at the frequencies a subwoofer would subject it to. To avoid or completely negate the ringing, a judiciously applied layer of Dynamat Extreme worked wonders. This is the rigidity reference, people. Had I welded bracing onto that enclosure, I could have further improved the performance... If I had used steel, couldn't I have used thinner material stiil? Due to the RIGIDITY of steel vs. aluminum, I probably could have. The gains in performance between MDF and HDP, are minimal, FAR beyond any point of diminishing returns. The only thing you will gain in a small enclosure (the kind specific to the autosound industry) will be weight and cost. MDF is a perfectly useable building matereial for <2 cu. ft. enclosures... hell, for that matter, 8 cubic foot enclosures. As your enclosures get larger, (and I mean LARGER) your point of diminishing returns gets closer to the trade-off between weight/cost and performance when you use HDP. There are advantages to using it in GIANT enclosures, although I do not believe for one second that the MATERIAL makes the acoustic difference, in and of itself. The difference comes from the rigidity and porosity of the enclosure, where the HDP can and will perform better in large pieces. The difference CAN be made up for using more bracing in a MDF enclosure, BTW... Again, Dave can't keep his nose out of it, and there's my two cents. Take them for what they are worth. (BTW, sedate, I have built enclosures from concrete as well... I don't recommend it.)It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."