The Ever Growing T-line

[Clif]

So im going to get into T-line boxes so i can teach my self and others about them.

My set up. 2 RE SE 10" woofers.

Few Calculations:

2 10“ subs

78.5 sq in x 2 = 157 sq inchs

200sq inches tapering down to 157 sq inch with the last 20 inches of port all 157sq inches

fs is 26.6 x .25= 6.65’ = 79.8” of port

I came up with a few desings then relized there not to practical for my situation.

Im putting them in a suv so im thinking subs up port back. From what i herd that seems to work pretty well with subs in suvs.

Now here come a question or 2.

how exact should i be with the length and width of my port?

Do i calculate where my subs mount as part of my vent or calculate it from the first turn?(or from the last sub in the vent)

will 45s in the corners or should i use resign to round them off?

Any other helpfull tidbits?

Cliff

[Forevrbumpn]

Thats where the whole quarter wave calculation comes in

30hz = 9.41ft long

find the Fs of the subs, or what you want to use, and find the quarterwave length of that number

[Clif]

yea fs of 26.6 quarter wave of that i think should be 6.65 ft or 79" is that correct?

[Clif]

well by doing your formula 1160/26.6=42.48/4= 10.62ft i get that

is that the correct way to do it? i herd take the fs and times it by .25? is this just the cheap and easy way?

[Clif]

k im dumb re did it and have 10.62 ft of port along with 70sq inchs for each sub or 140 for both.

[Forevrbumpn]

just curious, what altitude are you?

I know if well over 1000ft, the whole formula changes some

[Clif]

google earth said around 1040ft for st. cloud mn

[aznboi3644]

well by doing your formula 1160/26.6=42.48/4= 10.62ft i get that

is that the correct way to do it? i herd take the fs and times it by .25? is this just the cheap and easy way?

lol take fs and multiply by .25???? fs is the frequency measured in Hz...multiplying Hz times .25 does give you length.

[Forevrbumpn]

I knew that x's 0.25 looked odd

30hz = 9.41ft long at sea level, not 7.5ft long as the x's 0.25

would be nice if the numbers got shorter like that

Take Fs, 25hz x's 4 = 100

now take spd of sound 1130ft sec / 100 = 11.3ft long

[Clif]

so make it 10.62 ft long

1130/26.6=42.48

42.48/4= 10.62

Also the effective piston area is 48.05 (96.1 for 2) should i do a strait port design or start a lil smaller like 90 and finsh at like 105?

also do you just put a V in the box in the first vent for multiple subs?

Edited December 22, 2008 by Clif