Port ideas

[KyleBrown 121]

So I've decided that I don't like this 38-39hz tune at all.

We have 9.5 cubes (after disp)

current port is a 12.5 sonotube @14.5" long

I can maybe stretch it 17" maybe, but all that extra port will be external. But that's only 36-37hz

12" doesn't help much either...

If I can find a 11.5" sonotube I can get to 34hz @17" long

12.5"=122.6sqin of port=12.9sqin per cube

11.5"=103.8sqin of port=10.9sqin per cube

Most people's rule of thumb for round to slot port is 3-4"

so 12.9sqin per cube =15-16.9sqin per cube

10.9=13-14.9

So what do you ladies think?

Edited September 4, 2012 by armykyle1

[ricksi30 923]

Can't read that at all on my phone.

[KyleBrown 121]

Can't read that at all on my phone.

Dunno why lol

[ricksi30 923]

The font color.

[KyleBrown 121]

I think it's black but I tried again

[MikeMartel 64]

Dont see why it wouldnt work, try it out! Worst thing that will happen is that you still dont like how it sounds and need to try again?

[Duran 387]

Port area per cube is a joke (most of the time). You must calculate minimum port area per the driver(s) used and the desired tuning. Internal area doesn't matter either.

[Duran 387]

Port area per cube is a joke (most of the time). You must calculate minimum port area per the driver(s) used and the desired tuning. Internal area doesn't matter either.

[95Honda 486]

Yes^^. There is no realtion between enclosure volume and vent area. Power and driver displacement are the dominant factors. You need to model to find out what the vent velocity will be.

[ssh 924]

What drivers, amp, and "wiring down to?"

I'd pick some tuning point, and calculate the vent mach for xxx port area. If vent mach is too high at xxx port area, and you can't increase port area due to port length constraints, then consider upping the tuning point until you find a happy medium.

Edited September 4, 2012 by stefanhinote

[KyleBrown 121]

They're custom ufo BTL 18's with Zv3 sofparts. D1's

series/parallel to 1ohm. They'll be on a single DC5k for a short time then two DC5k's strapped @1ohm.

I've tried modeling the subs but keep getting errors.

The only TSP's I have are

(series)

SPL- 92.391w/1m

R(e)- 1.834

Fs- 34.99

Q(ts)- .41

Q(es)- .44

L(e)- 3.171

M(ms)- 306.1g

V(as)- 4.071cuft

I would put xmax in the 28-30 ranger since stock is 28mm but these coils are slightly longer.

[KyleBrown 121]

No I do not know the BL

[ssh 924]

I came up with:

For two of those drivers with 6kw with 35hz tuning:

100in^2 vent mach 48.275 m/s / 0.14

130in^2 vent mach 37.135 m/s / 0.108

150in^2 vent mach 32.183 m/s / 0.093

180in^2 vent mach 26.82 m/s / 0.078

200in^2 vent mach 24.138 m/s / 0.07

215in^2 vent mach 22.454 m/s / 0.065

Edited September 5, 2012 by stefanhinote

[KyleBrown 121]

I came up with:

For two of those drivers with 6kw with 35hz tuning:

100in^2 vent mach 48.275 m/s / 0.14

130in^2 vent mach 37.135 m/s / 0.108

150in^2 vent mach 32.183 m/s / 0.093

180in^2 vent mach 26.82 m/s / 0.078

200in^2 vent mach 24.138 m/s / 0.07

215in^2 vent mach 22.454 m/s / 0.065

Which program are you using?

[ssh 924]

I came up with:

For two of those drivers with 6kw with 35hz tuning:

100in^2 vent mach 48.275 m/s / 0.14

130in^2 vent mach 37.135 m/s / 0.108

150in^2 vent mach 32.183 m/s / 0.093

180in^2 vent mach 26.82 m/s / 0.078

200in^2 vent mach 24.138 m/s / 0.07

215in^2 vent mach 22.454 m/s / 0.065

Which program are you using?

http://portsgalore.s...om/?do=ventmach

The aero port section doesn't account for any flaring, just circular port area.

You can try it along with winisd.

Edited September 5, 2012 by stefanhinote

[ssh 924]

Also note that vas is in liters, not cubic feet, so you'll have to convert that.

[KyleBrown 121]

Also note that vas is in liters, not cubic feet, so you'll have to convert that.

Thank you. I didn't even look at that at first.

[KyleBrown 121]

tough choices ahead

[KyleBrown 121]

Looks like I'm going to give an 11" port a shot with the step down in power. Plus I'm thinking about getting some of those sa/oa 18's built. Need lows

[KyleBrown 121]

Thank you for the help guys.

[ricksi30 923]

Looks like I'm going to give an 11" port a shot with the step down in power. Plus I'm thinking about getting some of those sa/oa 18's built. Need lows

You're going to switch from what you have to Sa's? Sounds like a bit of a downgrade.

[ricksi30 923]

Just saw your post about the shifted motor

[KyleBrown 121]

Just saw your post about the shifted motor

It shifted on the basket. Noob mistake. Used washers for spacer and loctite on only one screw.... Drinking and sub building lol. I already paid for parts to rebuild it.

The SA/OA 18's should offer better low end and might perform better on the DC5k. I might have Nick use SPL coils, not sure yet. But I want then low lows

[ricksi30 923]

2500 a piece...?

[KyleBrown 121]

Hopefully

Looks like I could only find a 11.3" sonotube lol.