active room nuetralizer???

There’s a bunch of active and passive room "neutralizers" including but not limited to SteinMusic Harmonizer, tiny little bowl resonators of various manufacture, Lessloss Blackbody, 1 GHz Ultra Tweeters, Sugar Cubes from the tiny little bowl guy, Marigo VTS Dots for walls and windows, tiny crystals for room walls from Acoustic Revive, Schumann Frequency Generators of various manufacture primarily Acoustic Revive and Mpingo disc.

Erik_Squires wrote,
"Well, for slap-echo, the Bag End and other similar devices effectiveness is zero. :-)

Slap echoes are too coherent. Bass traps, etc. rely on the energy in the bass collecting in the corners. By sucking the energy out of the corners you eliminate the ringing. But this works because the rooms ring like a bell. If you put your finger anywhere on the rim of the bell it kills the ringing."

Give the Room Tunes Echo Tunes a try sometime. You’ll be singing a different tune. As it were. No one ever said Bass Traps did anything room echo.