6-pack of 4" absorptive foam provides 3 times the low-end control of 2" foam for unruly spaces.

Auralex 4" Studiofoam Wedges are recommended for medium to large areas like concert halls, gymnasiums and churches, rooms with pronounced low frequency problems or where sonic accuracy is mandatory and maximum acoustic absorption is required (e.g. voiceover or drum booths, forensic audio labs and mastering rooms). The 4" acoustic wedges provide 3 times the low-end control of their 2" version and can effectively tame even the worst sonic anomalies. In some instances, using 4" acoustic Studiofoam Wedges can lessen the need for significant dedicated bass trapping.

This SmartPak contains 6 panels which will cover 24 square feet of wall space.

Auralex 4" Studiofoam SmartPak Wedges Features:

Benefits
Provides 3 times the low-end control of 2" version
Can lessen the need for dedicated bass trapping
Maximum acoustic and low frequency absorption
Applications
Medium to large areas like concert halls, gymnasiums, churches, voiceover and drum booths, forensic audio labs, mastering studios

Auralex 4" Studiofoam SmartPak Wedges Specifications:

6 panels per pack
NRC: 1.10
Covers 24 square feet