Bass ports?

[Clapton is God]

I recently re-covered an old Kustom 3x15 cabinet and left out the aluminum bass ports. I don't really notice any tonal differences, but is there a reason to put them back in? The holes are still there, just not the long aluminum bezels. Thanks!

From this:



To this:

[sawzalot]

Yes, the length of those tubes factors into the design of the cabinet and it's low end tuning. You should put them back in. Plus they look cool.

[T-Bird]

Hi.

There's plenty of manufacturers that cheap out by using just a cutout as a port, but in this case the cutout only is most likely a bad idea.

You can use any tube that has the same dimensions, not necessarily the chromed ones if you don't like 'em for some reason.

That is obviously assuming that the speakers are the ones originally intended for that cab, if You swapped them as well, you might want to recalculate the porting in order to get the most out of the cab.

Regards
Sam

[Clapton is God]

Thanks guys. I guess I'll put them back in. The speakers are not original as they were blown when I got them.

[T-Bird]

Hi.

Originally Posted by Clapton is God

The speakers are not original as they were blown when I got them.

In that case, modeling the combination in WinISD or eqvivalent is what I'd recommend.

You can also post the internal dimensions of the cab, port diameter and the drivers you're using here, and someone can do the math for you if speaker modeling isn't your cup of tea.

Regards
Sam

[billfitzmaurice]

Originally Posted by sawzalot

Yes, the length of those tubes factors into the design of the cabinet and it's low end tuning. You should put them back in.

Not necessarily. That cab dates to the very earliest use of ducted ports, and I wouldn't count on them being properly engineered. Right off the bat they're obviously way too small; to prevent chuffing you'd need at least two ports of that size per driver.

In that case, modeling the combination in WinISD or eqvivalent is what I'd recommend.

+1, though that should have been prior to replacing the drivers, to know what to replace them with for best results.

[Clapton is God]

I tend to lean on the side of Kustom just haphazardly adding the tubes. The cab is thinner at the top than at the bottom, slowly tapering as it goes up.

The replacement speakers are Fender branded Celestions I found for $32 each on ebay. I have a feeling calculating any proper tube length would be difficult.

Still, most people say I'd be better off putting them back in rather than leaving them out, so that is what I'll probably do.

[runmikeyrun]

Originally Posted by Clapton is God

Still, most people say I'd be better off putting them back in rather than leaving them out, so that is what I'll probably do.

Who cares what most people say... you need to use WinISD to re-calculate what the proper port length should be. It may also recommend more ports like Bill said it should probably have. Before you waste your time putting them back in, spend a few minutes doing the calculations.