speaker encloser question

kd6vpe · Post by **kd6vpe** » Sat Apr 25, 2009 3:05 pm

My daughter has asked me to make some speaker enclosure for her boyfriends car. I'm thinking I should use particle board for this but I would really like to hear from the forum what your thoughts are. I don't know what size speaker nor do I know the size yet I was just curious about the acustics part of speaker enclosures. Thank you in advance for the advise.

patm1313 · Post by **patm1313** » Sat Apr 25, 2009 4:04 pm

MDF/particle board is the best material. Do not use plywood, it resonates too much. What are you covering the enclosure with?

kd6vpe · Post by **kd6vpe** » Sat Apr 25, 2009 5:29 pm

Thank you for coming back to me. I have not even thought of covers yet. I am waiting on her boyfriend to get up enough nerve to ask. My daughter keeps telling him I am looking forward to building them for him but he has not asked yet. Anyway I have never done this before so any input would be great. I have quite a bit of 3/4 mdf so as soon as he asks I can start. Thank you for re-assuring the acustic part of the question.

iclark · Post by **iclark** » Sat Apr 25, 2009 6:56 pm

Jim,

one old friend of mine took up woodworking just so that he could test his speaker enclosure designs whereas a different friend didn't care about the enclosure when he bolted 12 100W car sub-woofers into the frame of a LazyBoy double recliner couch.

in other words, welcome to the world of religion when it comes to design.

if you are not trying to do baffled, tuned cavities, then the first questions have to do with the purpose of the enclosure.

if the speakers are going under the back shelf or under the seats, then the enclosure is to protect the back side of the speaker. you need enough small holes to let air in and out to cool the coil and to not put a load on the cone as it makes the backside enclosure larger and smaller as it moves.

if the speakers are going into the interior of the vehicle, then mounting hard points become an issue. you do not want them becoming airborne as a result of violent collisions. I think that the 9g design criteria that we have to follow to mount something in an aircraft at work is overkill, but 4 or 5g is probably reasonable.

also, in the vehicle, they need to be small enough and located so as to not significantly increase blind spots for the driver.

I broke most of these guidelines in my younger days when I was driving VW beetles. after I rolled one, I started paying more attention to what people had been telling me about mounting things.

aiming the speakers to bounce the sound off the windshields can help the sound distribution, but might put more sound out into the neighborhood.

also, the thicker the enclosure walls, the more they act like a speaker mount rather than an active enclosure. using 3/4" MDF, I suspect that it would take a large bass speaker before something that thick would deform to the music.

sounds like a fun project and an experience to pass along to the grandkids if things eventually work out that way.

Ivan

patm1313 · Post by **patm1313** » Sat Apr 25, 2009 7:03 pm

Well, if he's going for looks, then your probably going to be working with fiberglass. More on that later. It depends on where and how he wants the speakers put in.

Fiberglass:

I could type it out, but i'll just give you a video.
http://www.youtube.com/watch?v=kcs1hz8z-9k

That's the basics.

If he's putting it in a discreet place such as under the seat or whatever, make a standard MDF box with holes cut for the speakers, and a hole cut for the wires. If you want, you can cover it in carpeting for some aesthetics. But as said above, bolt it down tight. There's few things more dangerous in a car crash then a 10lb speaker box flying around the interior.

kd6vpe · Post by **kd6vpe** » Sat Apr 25, 2009 9:25 pm

Wow,
Never thought about the flying object stuff Ivan thank you another one of these wood projects where safety has to be not only concider in the creationg of the object but also the use of the object. You see it is never wrong to ask I would have never thought of the mounting part. Now when he does ask I can be more informed. Thank you and when the project begins I will share the build and result up here. Thanks again folks.

iclark · Post by **iclark** » Sat Apr 25, 2009 10:30 pm

Jim,

you're more than welcome. I'm with the others here in looking forward to seeing what develops.

Ivan

efmaron · Post by **efmaron** » Sun Apr 26, 2009 11:14 am

Jim
Check out a TV program called Unique Whips on the Speed chanel. It is about a custom car builder, and just about every show has some thing to do with building speaker enclosures.