How much polyfill should I use?
Documented on the Building a speaker box for a 6x8 speaker out of build
Published June 8, 2026
Start with a light stuffing that lines the walls and fills about 10–30% of the internal volume depending on desired damping; overstuffing can overly damp low frequencies.
Full Answer
Start with a light stuffing that lines the walls and fills about 10–30% of the internal volume depending on desired damping; overstuffing can overly damp low frequencies. For small boxes, a thin layer is usually sufficient.
Documented In This Build
Related Parts
Primer/paint (and brushes/roll)
$20
MDF sheet (3/4")
$35
6x8 speaker
$60
Speaker terminal cup / binding posts
$8
Wood glue (PVA)
$7
Silicone sealant / caulk
$6
Port tube (PVC or pre-made)
$5
Speaker screws / wood screws
$3
Polyfill / acoustic damping
$8
Speaker grill or cloth
$10
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Clamps
Wire stripper / crimper
Circular saw (or table saw)
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