An absolute must for any speaker mounted without the benefit of a baffle, speaker enclosure or sealed door panel/rear deck area. It can make a world of difference. If you really love your music, these are an must for any stereo system that has a need
Idea for use a sealed space to isolate the impact of external factors on the speaker, usually used on mediant speakers
When used for DIY bookshelf speakers and home audio systems, it can effectively isolate the negative effects of subwoofers, making mid-range sound clearer and purer
When used to install car audio systems, it can reduces panel-to-frame and door panel reverberation and road noise for improved acoustics
Outer diameter: 122mm / 4.8", inner diameter: 102mm / 4.0", total height: 65mm, inner height: 60mm, screw hole diameter: 5mm, center distance of mounting hole: 116mm / 4.6", reserved a round wiring hole with Diameter: 8mm, which needs to be sealed after wiring is completed
Suitable for 4" speakers, requiring the inner height of the speaker to not exceed 60mm / 2.4"