Tim93se5sp

iTrader: (1)

Has anyone used lexan, or a similar thin material to build speaker enclosures? I am planning on building boxes that will fit inside my front doors for my 6.5" focal midranges. They will be as close to .5 cubic feet as i can get, but was wondering about the flex that this material has. It is strong for sure- do i use epoxy to bond it together? What can i do to brace it so it doesnt flex? Thanks alot,
Tim

Sin

Unless you can remove the inner door from the outter door, this is not feasible.

jmax

Lexan, aka polycarbonate. It's a good material but the material you want is fiberglass. There are several different resins to choose from and several differant fabrics that can achieve the stiffness you want. But decide for sure if sealing a 1/2 cubic foot inside the door panel will sonically be better than the free air alternative. The better from an SQ perspective is free-air. Power handling is a little lower, but if crossed over properly they should still be able to handle gobs of clean power.

d_warner

Like it has been posted, getting an enclosure inside the cavity of the front doors is going to be extremely hard. HTe Focals sure do just fine free-air.If you insist, 3/8 lexan, if thats what you're set on using, should be plenty stiff. Also where ever you get your Lexan, that dealer should be able to provide you with the proper lexan adhesive for building the set up. Make sure you ask alot of questions though, it has to be cleaned properly before being bonded!

Tim93se5sp

iTrader: (1)

Thanks- I am just toying with the idea for now. I was under the impression that a sealed enclosure would be beneficial, but I havent actually had the opportunity to compare, myself. Thanks for the responses.

chinaonnitrous1

iTrader: (12)

hmm..would you like some focal utopia 7" midbass? I've got 3 pairs..

Sin

I disagree regarding the Focals. I myself have no tried Focal Access and Polykevlars in my Maxima, and I can tell you right now, these puppies HATE, ABSOLUTELY HATE free air. They lack a lot of upper mid range when in free air.

If you want to run the Focals, I HIGHLY suggest you seal off the inner and outter door. Focal speakers sound absofreakinlutely great when tuned right, but get em wrong, and you'll be wishing you left your stock speakers in there.

jmax

No one said not to seal off the door. I guess it is generally assumed that if you spent money on Focals that this would already be done. I still think most speakers will sound best free air. Some will loose significant power handling though. And this could allow the speaker too little control over particular frequency ranges. Personally I would listen to the speakers in my own vehicle and with the rest of the system in the doors without a sealed enclosure first. If it doesn't sound as good as you expected then start with the custom fabrication. I would feel pretty dumb if I spent a week building custom door pods and then heard the same speakers in someone elses car without custom pods and not be able to hear a noticable decrease in the SQ.

Sin

Oh definetly. I always play the speaker free air first. But 99% of the time, it can be optimized. When I played the Focals free air, I cringed. It wasn't until I found the right enclosure volume that I was really impressed. I generally take a look at the specs of the speaker to figure out the volume I will need, and work from there. I have a 6.5" tube that I use with a slider in it to adjust for volume. From experience, I have found that most 6.5" mids like about 1.5-2.5 cubic feet.

After TOTALLY sealing off my doors, my speakers sounded SO MUCH clearer and louder. Mid range bass was much more defined. Admittedly, it was a lot of work to seal off the doors as I had, and quite a bit of creativity, but I definetly think it was worth it.

Tim93se5sp

iTrader: (1)

This may sound like a dumb question, but what do you mean by sealing off your doors? I am guessing that perhaps you can effectively use the inner part of the door as a semi-sealed enclosure (although it wont be perfect due to the window, etc) Am I correct in guessing that you are filling all other holes with some kind of material? Thanks,
Tim

One more Q- should I be at all concerned with water touching the speaker if I use a free-air setup? The seal at the top for the window cant be perfect and must allow some water in, as there are drains in the bottom of the door. What can I do to protect them?

Sin

You got it. Seal off the inner door so as to make the door itself an enclosure. I dynamatted everything, right over the holes. And you are right, there will be some leakage around the window seals, but minimal enough that it will still sound like a sealed enclosure. And as for water, that's why there is a shield for the mid. Have you ever opened up your door? Give it a go, you'll learn a lot, and decide just how much work you are willing to put in for a small, but very noticeable gain in sound quality.

Tim93se5sp

iTrader: (1)

Putting dynomat over the holes is enough to make a noticeable difference in sq? I thought something more solid would be necessary.

I haven't been able to look up into the door from the speaker hole, but remember, I have a 3rd gen- I didnt think there was anything protecting it. Thanks for the input.

jmax

The dynamat or whatever you use can affectively seal the door. It won't be like a typical sealed enclosure as the walls would be able to flex. As for the factory door I think it has plastic shroud that covers the speaker to protect from water splashes.

Sin

For the small openings (less than .5" in diameter), just use the dynamat. How larger openings, use a piece of mdf and silicone it to the door, then dynmat over the mdf. For the part you can't hard cover, use polyfill, then silicone a sheet of plastic to hold it in place, seal off the enclosure, then dynamat over the plastic sheet.

jmax

Everything can be hard covered. But the advantages over just using dampening material will be hard to distinguish. And with over a couple hundred watts in each of my doors I havn't had troubles with a partial covering.