cutting or elongating a port results

[Deedubs]

I'm kinda of a knob at this, but one of my buddies asked me a question that i didn't know the answer to, and cant stop thinking about.

he has a 1x15 speaker cab with a single port in the back. he replaced a 8ohm 200w speaker with an 8ohm 300w speaker.

will it help to cut the port tube down to keep it from farting out, or will elongating the port tube do the trick.

to me i think cutting it down might help, but i don't want to tell him to do that cuz i really don't know if that will help or make it worse.

 

[1958Bassman]

I'm kinda of a knob at this, but one of my buddies asked me a question that i didn't know the answer to, and cant stop thinking about.

he has a 1x15 speaker cab with a single port in the back. he replaced a 8ohm 200w speaker with an 8ohm 300w speaker.

will it help to cut the port tube down to keep it from farting out, or will elongating the port tube do the trick.

to me i think cutting it down might help, but i don't want to tell him to do that cuz i really don't know if that will help or make it worse.

The driver's characteristics, e.g., Theil-Small Parameters, determine the correct box volume and port diameter/length. You could make it shorter or longer but without knowing how much and which you should do, it's just guessing.

If you want to model the driver and box, you could download WinISD- it's a free program and it calculates vents, box size, response, group delay, etc. It doesn't show power handling, though. That's a major omission and if you really want to do it right, BassBox Pro is better. For any program, you'll need the parameters, which may be available from the manufacturer.

 

[Deedubs]

thanks for the info. i take a look and see if i can make anything of it.

 

[uhdinator]

Throwing a new speaker in a cab that is not original spec for that cab will change how it sounds. Could be better, could be worse. The volume inside the cab, port size and length all determine the freq response of the cab and was designed around the specs of the original driver in it.

 

[Deedubs]

Throwing a new speaker in a cab that is not original spec for that cab will change how it sounds. Could be better, could be worse. The volume inside the cab, port size and length all determine the freq response of the cab and was designed around the specs of the original driver in it.

i get that at a basic level, but i didn't know if shorten or lengthening a port cloud help tune the cab with higher wattage in anyway, or not at all. thanks for the info.