# JL 10" box size



## djhamp (Sep 14, 2012)

Sorry for the noob question, I did try searching. I have one JL 10w3v3 that I bought at a installer shop. They had a generic box that I got for $30. I am running 300 watts to it in the trunk of a Chev Cruze. I was reading here about the mfg specs for sealed boxes often being too small (JL says .625 cu ft.)

I installed winISD and plugged in the speaker and it says the volume should be 42.4 (?) whatever that means. I have never used the software so I am sure I am doing something wrong.

So - what is a good size for this speaker? I am going for the best SQ.

Thanks!


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## HondAudio (Oct 19, 2006)

djhamp said:


> Sorry for the noob question, I did try searching. I have one JL 10w3v3 that I bought at a installer shop. They had a generic box that I got for $30. I am running 300 watts to it in the trunk of a Chev Cruze. I was reading here about the mfg specs for sealed boxes often being too small (JL says .625 cu ft.)
> 
> I installed winISD and plugged in the speaker and it says the volume should be *42.4* (?) whatever that means. I have never used the software so I am sure I am doing something wrong.
> 
> ...


42.4 refers to liters as a unit of volume. Using Google, we get:

Google

42.4 liters equals 1.49734 cubic feet.

The question now is: "how big is the prefabricated enclosure?" If it's at least 0.625 cubic feet net (accounting for the volume that the speaker itself displaces), then you're good-to-go. It won't hurt if the enclosure is larger than that, unless it becomes larger than the _Vas_ measurement, which JL Audio indicates as _Equivalent Compliance (Vas) 1.138 cu ft / 32.23 liters_. If the enclosure is larger than that, the speaker will act as if it's in an infinite baffle setup, rather than a sealed enclosure.

You didn't indicate if WinISD gave that "42.4" as the volume measurement, but I'm assuming as such based on the context here. As long as the net enclosure volume is at least 17.698029 liters (0.625 cubic feet), you'll be OK.

I hope I'm right on this


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## Spyke (Apr 20, 2012)

A sealed enclosure can never be too big and like honda said, It eventually becomes like ib when the box stops having an effect on the woofer. I recently just started using larger boxes. As an experiment I started out with an 8 that recommends an enclosure size of .23. Winisd gave an optimum size of .56. So I put it in a .70. I have always used small enclosures and this just about blew my mind when I realized how wrong I had been. The bass was smooth, non peaky, and deep. I was now very interested in what a larger driver could do. I put a 12 that recommends 1.45 into a 2cu ft enclosure. The result was like nothing I had heard before.(I don't get out much ) The sub bass finally sounded like sub bass, not the punchy rattle boxes I was used to.

The size of the box determines sound and power *requirement*. A smaller enclosure will give a peakier response and it will take more power to drive it to full output. A larger enclosure will give deeper response and will require less power to drive to it's full output. 

If the JL models a box of 1.5cu I would say go bigger, maybe 2cu. Be careful though, the larger the box, the less power it needs, and this is a good thing.


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## Spyke (Apr 20, 2012)

HondAudio said:


> 42.4 refers to liters as a unit of volume. Using Google, we get:
> 
> Google
> 
> ...


I humbly disagree with this. I didn't see this at first.


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## HondAudio (Oct 19, 2006)

Spyke said:


> I humbly disagree with this. I didn't see this at first.


Fair enough. It's implied that that's the minimum enclosure size


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## Spyke (Apr 20, 2012)

HondAudio said:


> Fair enough. It's implied that that's the minimum enclosure size


Yeah, I agree with that. The problem is that the min size will prob yield high power handling/consumption and low sq. The manufacturer is trying to keep nimrods from smoking their sub by suggesting that small of an enclosure. Also prob trying to boost sales by convincing people they can fit 2 or 3 in their car. The average person prob won't know the difference but it sounds like the op hears that something isn't quite right.


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## djhamp (Sep 14, 2012)

HondAudio said:


> 42.4 refers to liters as a unit of volume. Using Google, we get:
> 
> Google
> 
> ...


OK - please dumb this down for the noob (me). You're saying winisd is telling me the box should be 1.49 cubic feet but then you say it shouldnt be bigger than the Vas - which is 1.1 cubic feet? Again I am looking for the best SQ - I am not worried too much about the power as I dont run it anywhere near full blast.


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## Spyke (Apr 20, 2012)

Forget about vas. For the driver to behave as it would in an ib alignment the qtc would have to match the qts of the driver. I didn't intend that for you dj.

Ok, I modeled a JL 10w3v3 4 ohm and got a box size of 1.012 cu. ft. It looks like a pretty well behaved sub imo. I modeled 3 different box sizes(.63, 1, and 1.5). The f3's are all about 46hz. But a 1.5cuft will give better low response(30hz is up about 3db) 2cuft does a little better but not much. I would say a 1.5 cu enclosure would be good for this sub imo. 

I don't know why I came up with a different size than you did. I used winisd and took specs right from the jl manual. Could you post your specs just so I can be sure?


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## djhamp (Sep 14, 2012)

Spyke said:


> Forget about vas. For the driver to behave as it would in an ib alignment the qtc would have to match the qts of the driver. I didn't intend that for you dj.
> 
> Ok, I modeled a JL 10w3v3 4 ohm and got a box size of 1.012 cu. ft. It looks like a pretty well behaved sub imo. I modeled 3 different box sizes(.63, 1, and 1.5). The f3's are all about 46hz. But a 1.5cuft will give better low response(30hz is up about 3db) 2cuft does a little better but not much. I would say a 1.5 cu enclosure would be good for this sub imo.
> 
> I don't know why I came up with a different size than you did. I used winisd and took specs right from the jl manual. Could you post your specs just so I can be sure?


Cool, thanks much!
I think the box I have is around .9 cuft, probably OK. It looks good but I think its 1/2 wood. I am thinking I can make a beefer box with bracing - cant hurt. 1.5 cu is still small enough that my wife wont complain about grocery room too much!

I had pulled the specs from their web site
Free Air Resonance (Fs)
32.97 Hz
Electrical “Q” (Qes)
0.533
Mechanical “Q” (Qms)
7.027
Total Speaker “Q” (Qts)
0.495
Equivalent Compliance (Vas)
1.136 cu ft / 32.17 L
One-Way Linear Excursion (Xmax)*
0.550 in / 14.0 mm
Reference Efficiency (no)
0.21%
Efficiency (1 W / 1 m)**
85.37 dB SPL
Effective Piston Area (Sd)
53.475 sq in / 0.0345 sq m
DC Resistance (Re)
1.70 Ω


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## Spyke (Apr 20, 2012)

Ok, I had modeled a 4 ohm and you have a 2 ohm. Doesn't matter though, it didn't change the response. Half inch might be a little thin. I always use 3/4" mdf. But, If you really aren't cranking it and space is at a premium you could get away with 1/2". Btw, You are calculating the enclosure volume with the wood thickness subtracted?

Speaker Enclosure Volume Calculator 

^This is a great site. Tons of useful info. There are a couple enclosure calculators on here which might be useful.


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