I've spent $500 plus to hear the wife!!!
Firstly i will comment that lead is not common for sound deadning these days due to health concerns. It has largely been replaced by Barium loaded vinyl products. Infact the covering of the seatbox in defenders is barium loaded vinyl albeit a very thin version. they are rated by transmission and absorbtion of sound at various frequencies and generally the heavier the better
I have replaced the TXcase in the defender 130 with 1.2Q version-good, one less whine but can now hear the rear diff. I also installed the Dieselgas system for more power.
Went to a good aussie company in Girraween -Sydney Pyrotek / sound guard. The guy said buy a differnt car! But they do the work on same LRs for the Army.
I put the self adhesive tar/felt pads every where, in doors, floor, hump, seat boxes. Adds weight to shift the resonant frequency down so you do not hear it. 1Kg / msq
I bought 2 x 4m x1.3m (7Kg / msq) rolls of silent tread designed to go under wooden floors in units etc and put oit under the floor mats front and rear, I put it up behind AC and recovered the front seat box under cubby box, removable panels under seats. Inside rear seatbox. Pulled rear seats out and put it all across the back of the 130s cab.
Then I replaced all floormats front and rear.
In the back seat floor I added a ribbed 5mm thick rubber and put aluminium trims at the door sills to hold it all down.
I filled all the seat boxes with stuff to stop them drumming. Passengers- 2 batteries, drivers- Tools, Rear - recovery gear and spare parts.
Next I want to put a heavy ute mat in the rear tub.
I have used a Sound meter along the way and it has dropped each stage.
Probably some 50Kg of products but i can criuse at 110Kph and talk to the wife and the kids can hear the tape player in the back. The gears change makes hill starts tougher but well worth it as 120 is still comfortable and i have had it to 140 odd
Spent $500 on sound products and $1300 for TX gears and $4600 on the gas system. Is a much nicer truck to drive both in town and on the open road.
Worth every cent to keep the wife happy.
zwitter