Port & Tube length

[Growly Lytes]

G`day,
I recently put together 2 4x10 cabinets using 8 Eminence Legend BP102.The cab specs are `
127 liter cab
4.48cf internal volume`
10cm round port no tubing added yet.
Usable Freq Range 40hz & 2hz.
Fs 35hz
What is the right tube length & port diameter needed ?
I use a Fender TB-600.I was told to extend the ports to tune the cabinets @ 40hz......is this right or should it be tuned lower to the fs @ 35 hz??
Please help somebody, i really am lost with all the differerent info regaurding this subject.

 

[mr.redpants]

G`day,
I recently put together 2 4x10 cabinets using 8 Eminence Legend BP102.The cab specs are `
127 liter cab
4.48cf internal volume`
10cm round port no tubing added yet.
Usable Freq Range 40hz & 2hz.
Fs 35hz
What is the right tube length & port diameter needed ?
I use a Fender TB-600.I was told to extend the ports to tune the cabinets @ 40hz......is this right or should it be tuned lower to the fs @ 35 hz??
Please help somebody, i really am lost with all the differerent info regaurding this subject.

Growly, I think you'll find a ton of information under "Amps" rather than live sound - the diyers hang out there. A search should yield answers to your questions.
Red

 

[T-Bird]

Hi.

The assumptions I made:

The volume is the volume of the box, I subtracted 10l for the drivers.
The 100mm tube has the wall thickness of 3mm making the id 94mm.

Quick modeling gave me these figures:

"Optimal":
Fb 44,95
Tubes 3*94mm*151.5mm
700W

The 30Hz
Tubes 2*94mm*300mm
500W

The 40Hz
Tubes 3*94mm*223.8mm
600W

BTW, according to Eminence, Your box is way too small, but then again you probably knew that already.

Regards
Sam