This is a small bass trap that works. I have one.
Bass Trap or Snake Oil
Happy holiday. This is a device no larger than the size of your head. You heard that right — these are advertised as a bass trap and a resolution enhancer. The wavelength of 25 hz signal is 45 feet. Even the 110 hz mid bass extends to 10.2 ft long. Is it possible physically to suck it up? Another form of Helmholtz resonator?

@jperry Could you verify? You refer to something different called 'E-trap'. |