Want to build an LLT enclosure for my 13W7

**ambs275** · **04-14-07, 05:20 PM**

I have a 13W7 that is currently in my second car. Since I rarely drive the car, I figured the sub would get more use in my HT. I have never built an enclosure before, but I am willing to learn. To get started what would be a good volume and tuning for this project? The parameters are as follows:

Free Air Resonance (Fs): 23.5 Hz
Electrical “Q” (Qes): 0.476
Mechanical “Q” (Qms): 7.517
Total Speaker “Q” (Qts): 0.448
Equivalent Compliance (Vas): 3.68 cu. ft. / 104.3 liters
One-Way, Linear Excursion (Xmax)*: 1.25 in. / 32 mm
Reference Efficiency (no): 0.269%
Efficiency (1W/1m)**: 86.3 dB SPL
Effective Piston Area (Sd): 107.35 sq. in. / 0.0693 sq. m
DC Resistance (Re): 2.41 ohm***
Nominal Impedance (Znom): Dual 1.5 ohm
Thermal Power Handling (Pt): 1000W
Driver Displacement: 0.21 cu. ft. / 5.9 liters
Net Weight: 52 lbs. / 23.6 kg

Thanks in advance.

**BoomieMCT** · **04-14-07, 07:50 PM**

The first step would be to download Unibox or WinISD and play with them a bit to see what size enclosure you want, what sort of performance, etc. There isn't just one enclosure size or tuning that works best. A good place to start would be a 2.6 cubic foot sealed enclosure with heavy fill. That should give you a Qtc of 0.707 and an F3 of 34 Hz.

**Ryan-T** · **04-14-07, 09:52 PM**

A guy on another forum put one in a sealed 2.3^3 box and liked it. He ended up rebuilding it into a dual, and selling his F113.

**ambs275** · **04-14-07, 10:18 PM**

I have been messing around with WinISD a bit but don't really know what I am doing.

I saw that other W7 on AVS forum, but I figured I would try to go ported. Maybe I shouldn't though since I am not experienced.

**WillyD** · **04-14-07, 10:28 PM**

You don't need experience to go with porting.

**BoomieMCT** · **04-14-07, 10:38 PM**

Quote:

WillyD wrote:

You don't need experience to go with porting.

I'm not sure porting is the best configuration for this, but people certainly have done it. Here is a quick (and I emphasize quick) rundown of the 13W7 in a 9 cubic foot enclosure. Not too bad I'd say.

**Exocer** · **04-14-07, 11:22 PM**

What size port were you using for the simulation?

**WillyD** · **04-15-07, 01:13 AM**

Boomie - That looks sort of similar to how I modeled it earlier. I'd tune it lower than 17Hz though, closer to 14Hz. 265-275liters looks good though.

**BoomieMCT** · **04-15-07, 08:46 AM**

Quote:

Exocer wrote:

What size port were you using for the simulation?

I was using a 52" long (!) 6" port (for a 17Hz tune). Like I said, these were a first chop at a design and probably shouldn't be your final numbers. There is much value to playing with the programs yourself!

**WillyD** · **04-15-07, 01:22 PM**

I think you mean 52cm.

**BoomieMCT** · **04-15-07, 02:05 PM**

Quote:

WillyD wrote:

I think you mean 52cm.

Nope. Unibox is saying 9.3 cubic feet, 6" diameter and 52" long (not cm.).

**WillyD** · **04-15-07, 04:24 PM**

Quote:

BoomieMCT wrote:

Nope. Unibox is saying 9.3 cubic feet, 6" diameter and 52" long (not cm.).

No it isn't dude.

263 liters, tuned to 17Hz, with a 6" port, gives me ~55cm for port length.

**Exocer** · **04-15-07, 04:32 PM**

Yeah, its definitely cm. Just happened to check a little while ago.

**ambs275** · **04-15-07, 04:36 PM**

I'm getting numbers pretty close to WillyD's as well.

**BoomieMCT** · **04-15-07, 05:00 PM**

Yeah, I would have too except I didn't save my JL13W7 file between when I made the graphs and when I opened it to check the lengths. It was set to calculate two 6" ports, not one. After updating my data I'm getting 23.39 inches or 59 cm. Good catch folks.

All of this being said, the port airspeed with one 6" port gets awful high below 20 Hz. That can be remedied by having two 52" long 6" ports.

**Exocer** · **04-15-07, 05:05 PM**

I probably wouldn't worry so much about port noise under 20hz...then again I have never built a ported sub so.

**BoomieMCT** · **04-15-07, 05:08 PM**

One 43" long 8" port is pretty good though.

**Blaser** · **04-25-07, 03:15 PM**

How much does this driver cost?

Blaser

**ambs275** · **04-25-07, 04:15 PM**

I believe I paid about $1,000 US. I bought it in 2003, so I don't really remember. MSRP may be a couple hundred more.

**Chester** · **05-21-07, 07:02 PM**

use passive radiators, i am running a 13w7, with dual 18" PR's (stryke audio) in an '8.3' cu. ft box (6 cu ft with actiavted charcoal to equal 8.3) which gives a -3db tuning of 15 hz (14 hz and a lot flatter after 2 peaking EQ's) even though it is +-3 db without EQ, after it is about +-0.5 (EQ simulations on WinISD are an incredible asset). I am running a crown K2 amplifier to the sub (1250 watts/ch @2 ohms RMS)...

**Chester** · **05-22-07, 07:08 AM**

also, if you input the inductance of the driver you will then get a high frequency rolloff simulation. when i designed my sub, I did not know this; hense the +-3 db response before EQ... JL does not list this spec and I had to call them a few times (to get a good tech), after obtaining four figures (JL uses the kippel measurement system so they do not even have an Le on hand) I found a conversion from kippel to T/S; in a series connection, (3 ohm mode) the Le is **6.32 mh**.

I wish i knew this BEFORE I build the sub. my DBX Driverack PA EQ'd it almost flat though

Peace.

**WillyD** · **06-14-07, 05:54 PM**

Chester - Could you provide the four klippel values concerning the inductance you got from JL?

**Chester** · **06-14-07, 09:50 PM**

I cannot remember where i found the conversion, somewhere on the internet...

JL FIGS (i called and talked to a tech at JL):
FLe: 24.2 hz
Krm: 0.0060
Erm: 0.82
Kxm: 0.0300
Exm: 0.069

**Chester** · **06-19-07, 09:53 PM**

http://www.acoustic-visions.com/~aco...indexold.shtml
^the passive radiators

http://www.hometheatershack.com/foru...materials.html
^i talk about ACE in this a bit... and give a source, check this and then ask

remember, i cite about 30% better however there is quite a bit of open space in there... look at the thread above

BTW, i have considered putting some rockwool in the sub too just to help absorb some higher resonances within the sub after reading some more on the net.

**Chester** · **06-20-07, 08:52 PM**

i do not cite a 30% improvement, I get a 260% improvement for x volume of carbon, and 100% (original) for the volume not used by carbon... since i use around 1.4 cubic feet of activated charcoal... my volume is as follows:
6 cubic feet total volume of sub (22^3/1728 ~ 6.16 cu ft, I round to 6 to compensate for driver displacement...)
6-1.4 = 4.6 cu ft of 'open volume'
1.4*2.6 = 3.64 cu ft 'augmented volume'
4.6+3.64= 8.24 cu ft of open and augmented volume combined (what the sub sees)

so yes, overall there is a 8.24/6= 1.3733... (37 percent increase) in combined volume, however when describing the carbon, i gave 260% for what X volume of carbon gives you.

I would assume this holds true for any 'stuffing' or filling, if you were to put 1 cu ft of stuffing in a 2 cu ft box and compare the overall 'percent increase' in volume with that of 1 cu ft stuffing in a 10 cu ft box, oviously the 2 cu ft box would have a greater ratio of stuffing to open volume and a greater 'percent increase' in apparent volume.

so BASICALLY: (initial volume)-(volume of carbon)=X (empty volume)
(volume of carbon)*2.6= Y (augmented volume)
X+Y= driver apparant volume (what you can put in your equations as box volume)

hope this helps

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