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View Full Version : box for 13w7 and tuning to 30 hz.



jlaudiow6
08-15-2003, 11:41 AM
I make a sealed enclosure for my 13w7 according to spec. requirements from jl audio. I hear ported is better but i also hear something about tunning to 30hz. what is that? Tuning to 30 hz?

subboxmaker
08-15-2003, 02:34 PM
when you port a box you have to take in to consideration box size, # of ports, and what kind of ports so that you can figure out how long the ports need to be so that the box is tuned to 30 hz. just look up port calculator on the internet and plug your box specs in and it willl give you the length and width of a port so that its tuned right to 30 hz

accord18
08-15-2003, 03:04 PM
a good port calculator is loudspeakers101.com/ventcal1

BDIDDY
08-15-2003, 03:23 PM
This is off topic but I saw some boxes that had a double layer of 3/4 MDF on them and was wondering why they do that?

abcdefg
08-15-2003, 03:26 PM
This is off topic but I saw some boxes that had a double layer of 3/4 MDF on them and was wondering why they do that?


just to add strength to the box

BDIDDY
08-16-2003, 02:21 AM
So if I put an extra piece on the front baffle of my box then I would notice a difference?

jlaudiow6
08-16-2003, 07:26 AM
Well, JL recommends 2.375 ft^3 tuned to 30 Hz using 1" MDF for the front baffle and 0.75" MDF for the rest of the enclosure ... JL is usually pretty good with their recommended ported enclosures ... Their recommended sealed enclosures are usually a little on the small side (Qtc usually 0.8-0.9) ...

And, for those of you with the big fuss about slot ports and height:width ratios, look what JL recommends for the 13W7 ... 17.25" height, 2" width ... That's 8.625:1 ;)

http://www.jlaudio.com/subwoofers/pdfs/13W7_MAN.pdf

See page 4 ...
So will it be better if i make a box plugin the specks to a 30 hz calculator, or the port box recomended by jl audio?

jlaudiow6
08-17-2003, 05:43 AM
The box shown in the manual is 2.375 ft^3 tuned to 30 Hz ;) If you cannot make the box shown in the manual due to space constraints, I can help you design a different one.

Also, if you don't have access to 1" MDF, use either one or two pieces of 3/4" MDF for the front baffle and add/subtract from external dimensions as necessary (1 piece = subtract 0.25" from depth, 2 pieces = add 0.5" to depth).
Thanks and but as for now i wont be makeing one soon. I need to find time first. Cause i dont think this will be a one day project for me.

niceuk
08-18-2003, 06:12 PM
hi to all. just to let you know i built that ported box from the jl tech sheet, it was mad took two people to lift but got 151db from that one speaker using 1000.1 amp and a standard car battery in a vauxhall vectra (small hatch to you in usa).will try to find photo and post it