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View Full Version : Box design help for single 15" FiQ



Freelander
08-22-2008, 08:33 PM
I can do 39" wide, 25" deep and I would like to keep it under 25" tall if I can. Its going in a suv so whatever port config you think will sound best.

Its going to be powered by a MMATS D300HC @ 1ohm.

Freelander
08-22-2008, 09:30 PM
wanting it to be tuned around 32hz

mcsoul
08-22-2008, 10:03 PM
Box outside dimensions.

use .75 mdf

D x W x H
20 x 24 x 18

Two 4" outside flare ports 15.3" deep.
remember the flare portion is actually counted
as half it's actual legnth. Mount the ports
along the bottom of the box 1 on each side of
the woofer; on the same side as the woofer.

Aim the box backwards try to give it 6-9" before
the sound hits the back wall. Then experiment with
the box closer/farther or pointed up. Once placed,
screw the box down with an L bracket.

3.56 cu^ft net after port(s) and woofer displacement.
32Hz tune.

3.97 cubes gross.


Credit someone else on the forum for this pic of port flare
calculation

Freelander
08-22-2008, 10:15 PM
I've never used flare ports. Is there any advantage over a slot port?

Freelander
08-22-2008, 10:19 PM
I would need two of these to do that design right? http://www.thrilleraudio.com/detail.aspx?ID=43

mcsoul
08-22-2008, 10:21 PM
"Flare" is just the design of the end of the port. It helps
air get out faster and also looks cleaner on the install.

You get 2 4" outside flares and 2 4" x 15.75" tubes.
Cut down the tubes to where they need to be.


http://www.partsexpress.com/webpage.cfm?WebPage_ID=3&searchHeader=1&manufacturer=301%20&sm=1%20&CAT_ID=48%20&ObjectGroup_ID=143

mcsoul
08-22-2008, 10:22 PM
I would need two of these to do that design right? http://www.thrilleraudio.com/detail.aspx?ID=43

That kit will certainly work too. Just trim the tube as needed.

Freelander
08-22-2008, 10:24 PM
"Flare" is just the design of the end of the port. It helps
air get out faster and also looks cleaner on the install.

You get 2 4" outside flares and 2 4" x 15.75" tubes.
Cut down the tubes to where they need to be.


http://www.partsexpress.com/webpage.cfm?WebPage_ID=3&searchHeader=1&manufacturer=301%20&sm=1%20&CAT_ID=48%20&ObjectGroup_ID=143

Since I've never worked with these port...what should the tube be cut down to for the right length?

MmatsDude
08-22-2008, 10:28 PM
nice amp, imguessing its modified cuz they run @ 2ohms stable.

wat dual is your q?

mcsoul
08-22-2008, 10:29 PM
If you just put the 17's you linked to in without cutting,
you should get like 30.5 - 31Hz range. Should be good to go.

Freelander
08-22-2008, 10:31 PM
the d300hc is going to run at 1ohm for the time being until I get the sub reconed so I can run it at 2 ohm. Although the mmats is 2ohm stable they can be ran 1ohm. They have a protection circuit built into them that I guess limits the voltage so they don't fry.

Freelander
08-22-2008, 10:33 PM
btw the amp benched 2100+ wrms at 2ohm when I bought it.

mlstrass
08-23-2008, 12:00 AM
4cubes at 32Hz works very nicely. Run that set up in the GF's car of 1k and it sounds good and hits low...

MmatsDude
08-23-2008, 12:07 AM
btw the amp benched 2100+ wrms at 2ohm when I bought it.

yeah i had one of those, amps are complete beasts mine was modified though!

mcsoul
08-23-2008, 02:31 PM
I thinks you need to add a little more depth to the box to use a 17" straight tube.
The air intake is too close to the back wall (2").
Let me recalculate.

Freelander
08-24-2008, 01:08 AM
I thinks you need to add a little more depth to the box to use a 17" straight tube.
The air intake is too close to the back wall (2").
Let me recalculate.

ok

Freelander
08-24-2008, 03:37 PM
anyone?

mcsoul
08-24-2008, 07:05 PM
18 H x 22 W x D 22
external dimensions

Two 4" x 17" cylinder flare
ports you linked to.

.75 MDF

4.0 cu^ft gross
3.55 cu^ft net after woofer and
port displacement.

3.55 @ 30.75 Hz