Sound deadening doors

[rorza Member Find all posts View Profile Close rorza]

I'm looking to sound deaden my doors as I upgrade my stereo and wanted to know how crucial the plastic door seals are. Has anyone heard of or seen someone install sheet metal panels (so that the dynamat can be placed over it) over the holes and sealed with sikaflex to stop water entering further into the cabin or should plastic just be put in place?

Thanks

[Shangus Find all posts View Profile Close Shangus]

I take it you mean the plastic behind the door skin. You can use sheet metal if you feel you need to seal the holes (how many watts are you pumpin into the doors?) but a better option is plexiglass or a nylon cutting board cut to fit. Metal just adds the potential for rust to start. If your not going big just run the dynamat straight over the holes with no backing . Makes it a lot easier if you ever need to fix anything in the door. Use dynatape to seal any gaps in the mat and just put the plastic seal back on top, will be better sealed than factory. Run a bit of electrical tape around any of the metal rods in the door mechanisms as well to stop any annoying rattles. I just hope your not lowering your prado and fittin 22" bling ;-)

[rorza Member Find all posts View Profile Close rorza]

Nah, man, 3" lift and 33" tyres, no low rider here. The speakers in question are 80w RMS Focals so my main concern is to make sure the quality of the sound coming out of the speaker is realised. I might just cut the dynamat around the holes and put some similar plastic back over the holes to seal it back up. Do you know if the black sealant used by toyota is similar to automotive grade sikaflex? The one they use seems to stay gooey rather than go hard.

Just FYI the plastic in question (Credit to Squeaky for the photo)

[Shangus Find all posts View Profile Close Shangus]

Sounds like some nice mods. Lifted is definitely better than lowered!! The black stuff might be butyl tape. If not it would be a good substitute. Leaving the hole open would be the way to go. It's a door not a sub enclosure so it shouldn't affect the sound quality. If you were pumpin 200w in there you might get some benefit. Put a piece of dynamat behind your speaker as well. No need to do the entire inner skin, just enough to deaden the area directly behind your focals. Hope this has been helpful.

[Bushbasher Out of control poster! Find all posts View Profile Close Bushbasher]

Only use sikaflex if you never, ever, want to take it apart in one piece again.

[Knighto Lurker Find all posts View Profile Close Knighto]

I'd be very interested in some photos during your install to see how you mount the speakers etc. Ive been thinking of an upgrade myself and want to know what I'm in for in replacing the 6x9's or what ever size is there now.

Cheers.

[rorza Member Find all posts View Profile Close rorza]

I'll try to remember to take pics throughout the process.

[PradoLAD79 Lurker Find all posts View Profile Close PradoLAD79]

Use one of these in each door directly behind the mid woofer. They make a huge difference, stops the bass from bouncing around inside the cavity cancelling itself out as it goes. Truly worth the $ I used them on a few installs, love Focal speakers one of the best. What size are you running? I am looking to upgrade soon, haven't taken the trims off to look yet.

http://www.jaycar.com.au/productView.asp?ID=AX3652

Luke

[rorza Member Find all posts View Profile Close rorza]

I was wondering about something like that. I'm guessing that you just used heavy duty double sided tape to keep the pad in place on the inner skin? The only problem I can foresee with installing those pads is that there is a structural beam running across the door directly behind where the speaker mounts so it would have to be cut in half then place above and below the beam, would still be effective I would think.

I plan on putting in the Focal P165v30 which are 6.5" but by all accounts handle the mid bass pretty well. Just getting a mate to make up the MDF mounts so that it fits, but after taking off the trim to have a look after a rainy day I was quite surprised at how much water was inside the inner skin, so might have to look at waterproofing the MDF a bit to make it last.

[Shangus Find all posts View Profile Close Shangus]

If you need to waterproof the Mdf just get some fibreglass resin and catalyst from a hardware shop. Pretty cheap and 100% watertight. Use it in boats all the time . Put a sheet of fibreglass matting down first if you want em strong and they would probably outlast the car :-)

[rorza Member Find all posts View Profile Close rorza]

Cheers Shangus, will keep it in mind.

[nubs Junior Member Find all posts View Profile Close nubs]

ive added sound deadening to both inner and outer layers. stripped out the plastic and cleaned off the butyl. took my time. around 2 hours for this door. I've got 6" splits in the front with tweeters in the factory position and 6" in the rear doors with MDF pods made up.

[rorza Member Find all posts View Profile Close rorza]

nubs - so you just covered the hole with dynamat and nothing else?

[qwerty_steve Junior Member Find all posts View Profile Close qwerty_steve]

Sound deadening is good to add mass, effectively blocking the interior cabin from outside noise, but what about panel resonances? When the frequency of music matches the natural frequency of a panel it resonates. It doesn't take that powerful a system to vibrate your body panels. Good news is there is a simple fix - constrained layer damping.

Don't listen to the sellers telling you that you need to coat your panels with the stuff either. A 3" x 3" square piece in the middle of most large panels will do the job. Not needed on small panels that don't flex.

Cheers,
Steve

[rorza Member Find all posts View Profile Close rorza]

Do you have any images to illustrate the product you're talking about or how it installed in a car door, qwerty_steve?