Wednesday, September 3, 2008

That pesky rear port

The trend in cab design these days (and for the past decade, it seems) has been to place a port for low end frequency extension on the rear of bass cabs and combos. This can work well in some situations, especially if the player is mindful that he can tune the cab by adjusting the distance to or from the wall of the cab.

However, these ports can prove more trouble than they're worth. For example, in a reverberant room, the low frequencies (which is all that come from those ports) can travel down the walls in both directions, making the wall a big bass horn, increasing the volume to absurd levels in the audience, while leaving you, the player, unable to hear yourself. It can change your sound and make it "boomy." Perhaps the worst of it, other players onstage can be blasted with an overdose of bass. We want to be heard, but who wants to deal with volume complaints about the bass all night?

The solution is to get some material, like foam, and stuff-stuff-stuff those ports. Fill them up. It will make the cab/combo sound different, in most cases tightening up the sound. If you don't like it, just remove the foam.

On many recent jobs, just to control the volume I've had to stick my coat behind my amp (at least unltil I foamed the ports).

Try it and see. You may like the result.

Zebron and James