Beginner
Amazon Basics
Amazon Basics deadening mat, 10 pack
$14.69The cheapest way to treat two door skins and find out whether the difference is worth more.
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Sound Deadening Coverage and Cost Calculator
Quick answer
Most of the resonance reduction from butyl damper arrives in the first 25 percent of coverage. A midsize sedan with 24 square feet of door skin needs about 6 square feet of mat at that coverage, which is well under one standard 36 square foot pack.
Result
Material needed 6 sq ft Convention
Packs to buy 1 x 36 sq ft
Estimated cost 45 USD
Total panel area 24 sq ft Convention
Panel areas here are planning figures by vehicle class. Measure the panel if the exact number matters, and buy one pack more than the calculation says for the offcuts you will waste around window mechanisms.
The formula
Material needed = panel area x coverage percentage, then divided by the pack size
Butyl damper works by adding a constrained layer that stops the panel ringing, and that job is mostly done at a quarter coverage. Full coverage adds weight for diminishing return. The second layer, closed cell foam, is what addresses rattles and road noise and it goes on at full coverage.
The figures above are computed with these exact inputs: Vehicle type sedan, What you are treating doors-only, Coverage 25 %, Price per 36 sq ft pack 45 USD.
What this calculator assumes
Some of these are published physics or manufacturer figures and some are conventions. They are not the same kind of number, so each one is labeled.
| Assumption | Kind | Where it comes from |
|---|---|---|
| Deadening Coverage: 25 | Convention | The 25 percent coverage guideline for constrained layer damper on a door skin. Manufacturers of butyl damper publish that most of the resonance reduction arrives in the first quarter of coverage, and full coverage adds mass for diminishing return |
Gear that matches this result
Every card below is in the page source. The calculator re-ranks them against your numbers and marks anything that falls short of what you just calculated.
Beginner
KILMAT
80 mil butyl mat, 10 sq ft
$19.99Ten square feet is roughly what one door skin at 25 percent coverage needs.
Check price on Amazon Intermediate
ZARBRE
Zarbre 80 mil, 36 sq ft
$39.97Thirty six square feet at the lowest price per foot here, which covers four doors properly.
Check price on Amazon Intermediate
CUKWUYBY
CUKWUYBY 80 mil, 36 sq ft
$48.99Cut into 33 manageable sheets rather than a single roll, which makes a door far easier to work.
Check price on Amazon Expert
KILMAT
Kilmat 80 mil, 36 sq ft
$69.95Kilmat is the reference budget butyl, with a foil layer thick enough to roll properly without tearing.
Check price on Amazon Expert
KILMAT
Kilmat 50 mil, 50 sq ft
$69.99Fifty square feet of thinner mat, which is the better buy when the job is a whole floor rather than four doors.
Check price on AmazonFrequently asked questions
- How does the sound deadening calculation work?
- Material needed = panel area x coverage percentage, then divided by the pack size. Butyl damper works by adding a constrained layer that stops the panel ringing, and that job is mostly done at a quarter coverage. Full coverage adds weight for diminishing return. The second layer, closed cell foam, is what addresses rattles and road noise and it goes on at full coverage.
- Are these figures published or are they rules of thumb?
- Both, and the page labels which is which. The Helmholtz port relation, the Thiele/Small alignment equations, cone area geometry, Ohm’s law, conductor resistance and ampacity, and manufacturer specifications are published and are labeled as such. Amplifier efficiency, cabin gain, the farad per thousand watts rule, port area per cubic foot and coverage percentages are conventions with no measurement behind them, and they are labeled as conventions.
- Why does this calculator sometimes refuse to give an answer?
- Because there genuinely is not one. A port can be too large in area for the box and tuning asked of it, a vented alignment stops describing a useful box outside a Qts range, and a sealed box cannot produce a total Q below the driver’s own. In each case the calculator returns nothing and explains why, rather than extrapolating past the end of a published relation.
- Do I still need an installer if I use this?
- Many owners do their own 12V work, and these are the figures that work is sized from. What matters is that a car battery delivers hundreds of amps into a short without hesitating, so the main fuse goes within 18 inches of the battery positive terminal and the battery comes off before power wire goes in. If any of that is beyond what you want to take on, a professional installer is money well spent.
Researched guidance, not professional advice. These results are planning figures from published relations and manufacturer specifications. Fit the main fuse within 18 inches of the battery positive terminal, because that fuse protects the wire and the wire is what starts a fire. Disconnect the battery before running power wire, use a grommet through every piece of sheet metal, and remember that sustained high sound pressure causes permanent hearing damage.