Originally Posted by pocketmaster
It is not loose. It is stapled down. One side is clearly longer than the other side.
I read somebody say that the cabs are not well made. The wood used for the little vertical vents looks like somebody shaped it with an ax. And no insulation on the back wall. What up with that?
Give the insulation visible in the vent area a spritz of flat black spray paint. Or... take the grill and driver out and remove the insulation that can be seen thru the vent, especially if it is very near the inside vent opening. It can easily be cut with a good pair of scissors. Insulation too close or in the vent will cause a reduction in vent effectiveness.
The amount and general placement of insulation is a design choice, and it can really impact cab voicing. In a case where the cab is not fully lined, doing so will usually result in smoother sound, but a loss of 'character' (like growl, etc.). You can easily experiment, but if you already like the tone of a cab, changing the insulation amount and placement will not necessarily result in an improvement. Insulation is a very low cost item that is easily installed (comes as sheets, often fastened with wood staples). Reflection and resonance in a cab are valid and potent tools for cab voicing.
Vent partitions look fine in the images. They do need to be solidly glued along their entire length.