Each test was performed using "Room EQ Wizard" and the UMIK usb omni mic. I sent a sine wave sweep from a single JBL monitor, with an 8" driver, into the microphone (UMIK) with one of the acoustic panels placed in-between. I also performed a test with no panel between the mic and monitor to compare the results.

Dope Panel
48"x16"x2.5"
100%Hemp Fiber composite (absorbent mass)

VS

GIK 244 (not the "flex range")
49"x24"x5.5"
4" fiberglass (absorbent mass)

Given the distance from the source (monitor) to the mic, and the results, it is unlikely that the difference of width between the panels had any impact. However, the depth of the panels should absolutely have an impact.