I'm preparing a box that will hopefully be home to 2 15" Xcons that will be powered by a saz-3500. My goal is not to get the best spl numbers. I do listen to a lot of rap yet at the same time I enjoy some Lenka, Utada Hikaru, or miss Swift to give some examples. I think I would like to tune around 30 or 31hz. So far, I was planning separate chambers and double baffle. This will be going in a smaller SUV, probably subs up, ports back. I am doing all my calculations and sketches w/ pencil and paper, so I may be off alittle due to rounding or way off due to poor math skills.

Max available space is 26L*37W*24H, after divider and sub dis I am thinking the box is 10.3ft^3. I feel my first decision is to figure out if this 5.15ft^3 is too large when website says 4ft^3 is opt. I feel the slightly larger box will help with low end output, but I do not know if it will be too much for the subs since I am already matching their rms capabilities with the amp. Your thoughts?

Next, I would like to use aero ports. I have spent some time trying to decide 4" or 6" but have not committed to either yet, mainly because I am trying to calculate too many scenarios by not knowing my box size goal. I seem to have picked up aeros require less port area than slots. Yay. But, I have read that range is anywhere from 6-12"/ft^3. Too me, that is a big range and I would like to hear more specifically what a good allowance would be for the aeros in my circumstance?

I value any input with my 2 road blocks, thanks guys.

When a manufacturer gives you an optimal volume, why not use that? Getting low is not a problem for the Xcons.

I have mine in a little over 3cf and they pound. Pounded the kerf port of my box in to a cracked submission in fact.

I am going to build a new box using SSA optimum ported specs of 4cf, but first I am going to glue a new board over the front to cover the port and try it sealed for a few days. Nothing to lose and maybe I will like it better sealed.

Great woofers, you will love them.

You can go larger then suggested, but you need to pay attention to the driver to make sure it is not unloading. The good thing about building bigger is that you can always glue in small blocks to reduce internal air space until you find your preferred sound. But keep in mind to let the drivers break in first before you make box changes. You could always tune a little lower to chew up internal air space too. Not saying 5 cubes is bad, not at all, just that you need to make sure the driver is playing comfortably with in it's limits and you are not risking mechanical failure.

Home audio guys will put a driver like this in an 8 cube box tuned to 18hz. So the idea is that it is all about the install.

When a manufacturer gives you an optimal volume, why not use that? Getting low is not a problem for the Xcons.

I have mine in a little over 3cf and they pound. Pounded the kerf port of my box in to a cracked submission in fact.

I am going to build a new box using SSA optimum ported specs of 4cf, but first I am going to glue a new board over the front to cover the port and try it sealed for a few days. Nothing to lose and maybe I will like it better sealed.

Great woofers, you will love them.

Thanks for the kind words about the Xcon. I wish more people would try them sealed, as they sound awesome and still have loads of output with loads of low end excursion.

I appreciate the thoughts so far.

Seems I will be alot safer off to stick to 4ft³ and call it day. I would like to see the subs last longer than recklessly installing them in a coffin from day 1.

Some rough estimates with aeros . . . 4ft³ tuned 30/31hz using one 4" aero needs to be ~7" long. This would give me [3.14(2²)7] about 88in² of port per sub. Give or take a bit for the flares, but I am not sure how to calculate that portion. But, this 88in² > 6-12in² per ft³, is this correct? Mathematically, this may be enough port area, but thinking about a 4" port that is 7" long is not enough.

A review of a sealed 15" xcon would be cool!

Every owner run them ported, and that is the only way I have heared them.

anybody have thoughts about the ports?

About whether to have them or not? Build them in, and then cover them up, as Sir-Lancelot was planning to do, so you can see what you like.

About the size? Your call as long as you still have the 12-16in square per cuft.

When a manufacturer gives you an optimal volume, why not use that? Getting low is not a problem for the Xcons.

I have mine in a little over 3cf and they pound. Pounded the kerf port of my box in to a cracked submission in fact.

I am going to build a new box using SSA optimum ported specs of 4cf, but first I am going to glue a new board over the front to cover the port and try it sealed for a few days. Nothing to lose and maybe I will like it better sealed.

Great woofers, you will love them.

Really good idea btw.

To find the overall aeroport length, here's a formula from precision ports

8466.4R^2

---------------- -1.463R = Lv

(Vb)Fb^2

Lv= port length in inches

Vb= volume of box in ft.^3

Fb= tuning frequency

R= radius of port (1/2 of diameter)

Should be placed at least one port diameter away from any inside walls, if possible.

Trim center tube 5" shorter than Lv from formula. Once assembled, the port should be 1" longer than Lv.

Plug your numbers into the formula, and it will tell you how long your ports need to be, and should help you decide which port you can fit. Also be aware that the flared end of the port is HUGE on the 6" version, so the proper amount of mounting space would be needed. I used the 3" precision ports, and I love the way my ported box sounds. They were on parts-express.com. If you don't like the textured front, you could sand it off and hit it with some spray paint (tape off the inside of the port to prevent overspray).

Hope this will be of some use to you.

Edited November 27, 200915 yr by Feel The Bass

Great, thank you for that formula, I had not seen it.

What kind of setup are you running? Im curious to know when you say you love the way it sounds.

I have a question. How do you calculate the port area if your using multiple round ports since its recommended that 12-16 sq.in be used per cb.ft?

Edited November 27, 200915 yr by wof131s

The only thing i know about multiples is from the psp website tool, you can put in the number of ports you plan to use. I am not completely sure about what your asking about. But I suppose you would just add the area of each port together, if they are in the same chamber, to get your total port area for that chamber.

Edited November 27, 200915 yr by c_b_

I (had) 4 RF P1S412's, not great, but they were in 1.805 ft.^3 each, and I had it tuned to 29 Hz. Lots of SQ, and could also get loud. Ran them on 150 RMS a piece, and I was very happy. Bought 4 1252w's, and ran them sealed. Not happy with output, gonna build a ported box, but I'll probably have to build a slot/vented box, because I wouldn't be able to fit the precision ports, even with elbows. As for using more than one port, go to carstereo.com I think. There's a port length calc that will give you answers about the same as this formula.

Ok, the manufacture says to use 12-16 sq.in of port per cb.ft of volume. What i was asking was how would i calculate that?

here's a formula for use with multiple ports:

Lv=(((2.35625*10^4*Dv^2*#v)/(Vb*Tb^2))-(0.614*Dv))

where:

Lv = Length of port

Dv = Vent Diameter

#v = Number of ports

Vb = Volume of box

Tb = Tuning Frequency

only problem I've found with this formula is it came out of "The Loudspeaker Cookbook" and I'm not sure the numbers come out right unless the measurements are metric which means all the inches need multiplied by 2.54 for centimeters and the volume needs multiplied by 28.316846592 to convert it to liters.... then the resulting Lv needs multiplied by 0.3937007874

i hate the metric conversion but Lance's formula is the only one I know of that works for figuring multiple ports.....

Ok, the manufacture says to use 12-16 sq.in of port per cb.ft of volume. What i was asking was how would i calculate that?

if you're building a box with a 4cuft target size multiply the 4 by anything in the range from 12-16 for the total port area you need to calculate with..... 4 x 16 = 64......

ok thanks guys.

here's a formula for use with multiple ports:

Lv=(((2.35625*10^4*Dv^2*#v)/(Vb*Tb^2))-(0.614*Dv))

where:

Lv = Length of port

Dv = Vent Diameter

#v = Number of ports

Vb = Volume of box

Tb = Tuning Frequency

only problem I've found with this formula is it came out of "The Loudspeaker Cookbook" and I'm not sure the numbers come out right unless the measurements are metric which means all the inches need multiplied by 2.54 for centimeters and the volume needs multiplied by 28.316846592 to convert it to liters.... then the resulting Lv needs multiplied by 0.3937007874

i hate the metric conversion but Lance's formula is the only one I know of that works for figuring multiple ports.....

Yeah. Hopefully I wont end up needing this formula. I'll just see how things go with 1 port per chamber. I hope my math works out.

I believe your asking about multiple ports. I found it easy to use the12volt.com calculator that way I don't have to keep doing all of the calculations

On jl audio website, it says to divide the cubic air space by the number of ports, then calculate the port. So a 4cubic foot box with two ports would be 2cubes for each port. 2x16 equals 32 inches of port area each and the length 40inches long and this is for a tuning of 31

Round port with 4inch opening for 2cubes, tune of 31 is 14.7inches long each. 6inch opening is 35.25long each

hope this helps

Good examples, thanks.