4bus

iTrader: (4)

Dave,


Looks like the stuff I was cutting into on my friends 388 hustler cockpit walls this summer.

Not really sure, the only way to know is build one and test next to an mdf box of the same size. The speaker world decided mdf was best, the boat world knows mdf doesn't like water. I hbae built sub boxes with clear lexan fronts and did not notice a resonance issue.

Some stuff is too absorbent. I was at the ces show and dynamat had a sub box lined inside and out, the speakers mad very very little sound. So a dense foam will rob you of noise.

Bose uses advanced composites instead of wood.

I'm sure if I was in you shop for a week with a frequency meter we would find the perfect material, or you would create it.


On a side note I put an mdf box with 4 12"s under the back seat of a checkmate that is kept on a lift in 2005. I called him tonight, box has no issues, and he pounds the boat and stereo. Home depot has 1.5 inch mdf that is good quality

sparkie124

Wow- didnt expect this responce when I posted the question. I have deciced to do more research before proceeding. I have 2 JL 10w5 and may or may not add a 10w7. I saw some boxes @ Waves & wheels that are marine sub enclosures and apear to be plastic. Has anybody used one or have any input.

Wildman_grafix

We used to make a lot of sub boxes out of sheet plastic, had to to fit odd shapes.

The key is to use internal bracing so the box doesn't vibrate, also a good damping material inside.

We also did some where we would use the foam in place packing to fill a void (in a bag).

Take the plastic off and lay a couple of layers of glass mat, resin it up and let dry.

Then dig out the foam and glass the inside. We did this as we were trying to proto type what would end up as a molded piece in production.

BTW

BOSE= better sound through marketing!

LOL

lightning jet

The perfect speeker box is made of concrete lol very water proof but a little heavy for boat use.

glassdave

iTrader: (1)

Yup . . . . . They make some neat stuff but for the money you can get better sound. Wayyy over marketed . . . Kinda like west system epoxy lol

4bus

iTrader: (4)

The reason I used BOSE for an example was to talk about how important enclosures are for speaker performance.

I'm not saying BOSE makes the best speakers out there, or has the best sound. Not even close.

Bose however is very clever at getting deep range frequency response and high spl from little speakers, the speakers themselves are not even high quality when compared to industry standards. They do this using band pass technology and extensive port testing. Using a great speaker is only part of the equation, when you have BOTH you are where you want to be.

I do own one BOSE item. It is a speaker dock for my Iphone that was a gift. I have to say it is quite impressive for it's size, especially when it comes to low frequencies.

Wildman_grafix

Hey 4bus,

I said that because its a bit of a inside industry joke, yes of course there is much more then the speaker itself.

I also have a BOSE wave that I won at a Northwest Airlines function. Sill have one friend that works as a transducer engineer at BOSE.

I worked at Harman Kardon (Harman automotive), for 12 years, you would be surprised what can be done with a correctly designed enclosure.

No harm meant.

US1 Fountain

iTrader: (1)

Does the shape of the box matter?
I have a free air sub mounted in a side storage compartment door and am thinking about building a box to line the inside to a more idea cu ft size for a correct sub, plus it'd be solid, not the FG lining. To do so would require the box made to fit inside the exiting storage compartment door opening as I don't want to cut it up for future changing back over.

Wildman_grafix

Hey Jerry, I can say yes and no on that one. LOL

First I assume you will not be using your free air sub in a box right?

As for the shape, in automotive we made some very strange shape boxes trying to pick up volume, if you end up with a very thin (front to back) box we measured less output for the same volume as a more traditional shape. But I am talking inverted woofers in boxes that were only a couple of inches thick.

If you are going to use a sealed box and have what size it needs do what you can to get the volume, I doubt you will have problems.

Just make sure the box is braced so it doesn't vibrate, and use a good fiber fill to cancel any unwanted reflections.

http://www.sonicelectronix.com/item_...iber-Fill.html

US1 Fountain

iTrader: (1)

Correct, replacing the free air. I have 10 3/4" depth to work with. Haven't done the math yet to see what I can end up with for max possible size, considering max possible W x L, and then shrink down if need be to get idea volume. Do you still use the fill for idea box sizes, or only when you are undersized?

Thanks