I was thinking about installing a 10" self powered subwoofer in the trunk of my 300D (I had a Subaru low profile one under the passenger seat but it stopped working yesterday and Subaru has been no help in getting it fixed or replaced).

Has anyone ever lined with trunk lid with any kind of insulation material like dynamat or fiberglass or something like what the hood pad is made of? I'm really surprised that Mercedes chose to keep the underside of the trunk lid just as bare sheet metal.

Thanks

Alex

__________________
1983 300D (parked for four years)
2012 VW Sportwagen TDI Manual
2001 Miata SE
1962 Chevrolet Corvair Rampside

Would've been an unneccessary expense for the MB factory to do it....no engine noise coming from there...no passengers in there...no reason to do it.

Some well-installed dynamat or something would probably seal it up nicely, though...You'll most likely need to shim and soundproof the metal wall between your trunk and the gas tank/rear seat area. When I put a sub in the trunk of my 300SD, that wall of sheet metal rattled like crazy.

Drive on,
Mike

__________________
_____
1979 300 SD
350,000 miles
_____
1982 300D-gone---sold to a buddy
_____
1985 300TD
270,000 miles
_____
1994 E320
not my favorite, but the wife wanted it

www.myspace.com/mikemover
www.myspace.com/openskystudio
www.myspace.com/speedxband
www.myspace.com/openskyseparators
www.myspace.com/doubledrivemusic

Pardon the ignorance, but when you install a sub in the trunk, the sound travels reasonably well into the passenger compartment? I know it's non-directional, but does it get through the diesel tank and past the rear seat? Thanks

I'll think about dynamating the trunk. Sounds like kind of an expensive endeavor though. I mainly want to insulate the trunk because if I install a subwoofer in there, I don't want everyone outside of the car to hear it. I don't want to become one of those annoying kids.

Alex

__________________
1983 300D (parked for four years)
2012 VW Sportwagen TDI Manual
2001 Miata SE
1962 Chevrolet Corvair Rampside

You're right, bass is largely non-directional, so if you're cranking it up, the bass vibrations will transmit thru your car, to the wheels, and to the ground, regardless of how well you soundproof. So if you've got the volume up, you'll be "one of those kids" no matter what you do...hahaha...Hey, they'll get over it. Just turn it down when the cops are around! haha...

As long as you've got everything tightened up, shimmed, or whatever it takes so there's no rattles, I wouldn't spend the $$$ it would take to make your trunk airtight...I wouldn't think it would make enough of a difference in the low end to be worth the cost...not to me, at least. Soundproofing your door panels, floorpans, maybe even the headliner, firewall, etc. would make a MUCH greater difference for your dollars. Eliminating road and engine noise has the same effect as adding wattage to your system. Makes a BIG difference. Notice the sound quality difference with your window or sunroof cracked open vs. with them closed? Or with your engine off?

I've got a 12" in a good sized box, with 300 watts going to it, no soundproofing, other than rattle-proofing a few things, and it kicks pretty hard.

In my 79 300SD, I just took the tray out of the first aid kit on the rear deck...It lets the bass come thru quite a bit punchier. And when I really crank it, the little door flaps around too...pretty funny to watch in the rear view mirror!

Mike

__________________
_____
1979 300 SD
350,000 miles
_____
1982 300D-gone---sold to a buddy
_____
1985 300TD
270,000 miles
_____
1994 E320
not my favorite, but the wife wanted it

www.myspace.com/mikemover
www.myspace.com/openskystudio
www.myspace.com/speedxband
www.myspace.com/openskyseparators
www.myspace.com/doubledrivemusic

Mike,
Thanks for the perspective. Thing that bothers me about these cars (mine atleast) is that the trunks are so small that I'd feel realy guilty about installing a large or medium sized subwoofer box in the back. It would further decrease the already dismal amount of usable space. I'm thinking about one of those tube type Kenwood self-powered units. Do you guys think that I should just spend the extra for a separate amp and sub unit? Thanks yet again.

Alex

__________________
1983 300D (parked for four years)
2012 VW Sportwagen TDI Manual
2001 Miata SE
1962 Chevrolet Corvair Rampside

You're welcome...I'm no stereo expert, but I've done a few DIY installs over the years, and have had good results with a little thinking and planning beforehand.

I have never owned one of the tubular ones, but I've seen them used, and they seemed to do the job. Really just depends on how much thumping you want to do vs. how much trunk space you're willing to give up!

Mike

__________________
_____
1979 300 SD
350,000 miles
_____
1982 300D-gone---sold to a buddy
_____
1985 300TD
270,000 miles
_____
1994 E320
not my favorite, but the wife wanted it

www.myspace.com/mikemover
www.myspace.com/openskystudio
www.myspace.com/speedxband
www.myspace.com/openskyseparators
www.myspace.com/doubledrivemusic

The key thing here is the AMPLIFIER!!! Currently I have one 10 inch Rockford Fosgate subwoofer in a small encloser, powered by 180 watts. It is definetely adequate, and I'm very nitpicky when it comes to sound! The bass enters the cabin well, and doesn't get excessively boomy. The trunk lid and walls are ALL Dynamatted. The trunk latch rattled a bit, so I added foam insulation in that area. I removed the plastic side liners, because they rattled way too much. I'll probably end up putting carpet over the Dynamat because it looks pretty bad now!

Remember, you need to get a decent amplifier or you WILL NOT hear decent bass!

When I did my 500E stereo (which includes a 12" sub powered by 400 regulated watts), I built the sub into the trunk floor; no wasted space. It was hard to find a subwoofer that could work with that much air, but necessity's the mother of invention and I instaled an AVI piece. I also Dynamatted everything back there, and it does indeed improve the quality of the sound transmitted (or, rather, eliminates unwanted noise from being transmitted)

Good luck!

__________________
"If God had meant for us to walk, why did he give us feet that fit car pedals?" Sir Sterling Moss

Michael
2014 E63S Estate
2006 SLK55
1995 E500
1986 Porsche 944 turbo

In light of the above comments, if you were still inclined to insulate trunk panels, a good solution would be what I did in the engine compartment of a Volvo 240

Black flexible foam rubber (various trade names such as Armaflex and others) can be obtained form various sources (HVAC supply house, Grainger catalog)...look under insulation in the yellow pages. This stuff is closed cell foam, with a smooth finish on one side, comes in self stick (very expensive) or non-adhesive (very reasonable), and comes in various thicknesses...1/4", 1/2", 3/4" etc.

I used half inch thick material, and used a contact adhesive to apply (formica adhesive works very well)

__________________
1984 300TD Wagon, 407,800 mi (current daily driver)
1985 300DT Sedan, 330,000 mi (gone to that great autobahn in the sky)

Thanks for all the great ideas. You guys are getting all fancy on me. Problem is, I'm kind of on a budget and can't really afford to spend the probably $500 on the proper amp and sub. I don't even really want hard hitting bass, I just want something that'll gently supplement the only adequate speakers I have in the car (pioneers front and back). I was actually very satisfied with my Subaru unit until it broke.

I was thinking about just installing the Kenwood self-powered tube unit either in one of the rear foot wells or in the front of the passenger footwell up against the firewall. I rarely carry passengers and could just remove it on those occasions.

I really don't know. I can't decide whether or not to do this or to try and find a bargain way to go all out. ARGH!

Alex

__________________
1983 300D (parked for four years)
2012 VW Sportwagen TDI Manual
2001 Miata SE
1962 Chevrolet Corvair Rampside

One thing to remember is self control! When you get involved with stereo gear, it's WAY TOO EASY to get carried away and blow lots of money on expensive components, especially when you hear how sweet they sound. It's up to you to decide, if in the end it's worth it.