# Subwoofer Box Design



## NichB77 (Mar 12, 2011)

I recently upgraded my JL Audio 12W3 to a JL Audio 12W6. The 12W3 was in a ported box built by a local shop. The dimensions are 17.5"x13"x16" (WxHxD) and the port is 2.5" wide 11.5" high and 11.75" deep. With my amplifier settings all set at stock still and my head unit at 0 for subwoofer EQ it was producing great bass. When I purchased the 12W6 I decided I would make my own box and build it to the JL recomended specs which is 26.25"x14"x13" (WxHxD), and the port dimensions are 1.5" wide, 12.5" high, and 10.75" deep with a 16" extension. With this sub I am using factory settings on the amplifier, but to produce the same bass as the 12W3 did I have to turn the subwoofer EQ up to +15 on the head unit. I do not see why this is, seeing as it is a better subwoofer in a box built to JL's specs, but many people say it is the port width and I somewhat agree. Can anyone out there confirm this for me and possibly help me design a box that brings the 12W6 to its full potential. I have been searching the internet for a program that will design a box for me, but I have had no luck.

Any help is appreciated,
Nick


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## onefaststang (Mar 1, 2011)

When you built the port did you use the dimensions given for the inside of the port, or the outside?

Double check your measurements.
I know its a PITA but you can experiment with port dimensions.

Have you given the sub time to break in?


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## NichB77 (Mar 12, 2011)

I doubled checked all of my dimensions, and they are correct according to what JL's website specifies. I used the inside port width dimension because that is the dimension they gave on the website, but that did have me thinking for a second becuse 2.75" sounds much more reasonable. Testing different port sizes is my last resort. If I can find something or someone that can help me get it right the first time, so I don't have to spend too much time and money on just the box.


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## NichB77 (Mar 12, 2011)

Also, I have had the subwoofer for about 4 months now, but thats about as long as I had the 12W3 for.


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## Danometal (Nov 16, 2009)

Most owners of a W6 run them sealed.


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## NichB77 (Mar 12, 2011)

I thought about going with sealed, but I wanted to get as much bass as possible because I'm getting good mids and high from my two pairs of C5s. If I do build a sealed box is it still going to produce as much bass as it will in a good ported box?


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## Chaos (Oct 27, 2005)

Using manufacturer enclosure specs, the W6 is not to going to perform any better than a W3 without giving it more power.

plug the specs into WinISD and see for yourself:

LinearTeam


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## ChrisB (Jul 3, 2008)

Chaos said:


> Using manufacturer enclosure specs, the W6 is not to going to perform any better than a W3 without giving it more power.
> 
> plug the specs into WinISD and see for yourself:
> 
> LinearTeam



X2. I find that JL Audio's recommended subwoofer enclosures tend to miss the mark, by a HUGE margin!


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## NichB77 (Mar 12, 2011)

There is also more power I forgot to mention that. The W3 was powered by a pioneer GM-D7500M, and the W6 is powered by an alpine mrp-m1000:


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## nick650 (Feb 7, 2011)

GO SEALED!

I had the box to ported built it myself to JL spec and then I did sealed to 1.5 and 1.25 cubic feet The 1.5 did SO good I decided to build a box for both my 12w6v2's with full on bracing. Just do 1.5 sealed and don't look back.


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## NichB77 (Mar 12, 2011)

Im really thinking about it, but 1.5 cubic feet with bracing means its gonna be pretty big and idk about sealed boxes because I don't have any experience with them. Do they make as good and clear of bass as ported boxes do?


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## NichB77 (Mar 12, 2011)

Chaos, before I posted this I downloaded WinISD to check it, but the program would not work on my computer for some reason no matter where I downloaded it from.


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## 60ndown (Feb 8, 2007)

12w6 will have better everything then the 12w3 just need more power,

turn hu settings to flat and the amp gains up 

*flame suit on*


and there are no factory settings for an amp, you have to set them 



NichB77 said:


> I recently upgraded my JL Audio 12W3 to a JL Audio 12W6. The 12W3 was in a ported box built by a local shop. The dimensions are 17.5"x13"x16" (WxHxD) and the port is 2.5" wide 11.5" high and 11.75" deep. With my amplifier settings all set at stock still and my head unit at 0 for subwoofer EQ it was producing great bass. When I purchased the 12W6 I decided I would make my own box and build it to the JL recomended specs which is 26.25"x14"x13" (WxHxD), and the port dimensions are 1.5" wide, 12.5" high, and 10.75" deep with a 16" extension. *With this sub I am using factory settings on the amplifier*, but to produce the same bass as the 12W3 did I have to turn the subwoofer EQ up to +15 on the head unit. I do not see why this is, seeing as it is a better subwoofer in a box built to JL's specs, but many people say it is the port width and I somewhat agree. Can anyone out there confirm this for me and possibly help me design a box that brings the 12W6 to its full potential. I have been searching the internet for a program that will design a box for me, but I have had no luck.
> 
> Any help is appreciated,
> Nick


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## NichB77 (Mar 12, 2011)

The 12W6 is getting 600W RMS @ 4 ohms and the 12W3 was getting 200W RMS @ 4 ohms, and by factory I meant whatever the settings were when I took the amp out of the box. I turn the hu flat and try to play with the gain and such.


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## 60ndown (Feb 8, 2007)

http://mobile.jlaudio.com/products_subs.php?series_id=4

12w6 is dual 4 ohm, so you either connect it for 2 ohm or 8 ohm.

there is no 4 ohms with a 12w6. it has 2 coils, each coil is 4 ohms, each coil must be connected.



http://mobile.jlaudio.com/support_pages.php?page_id=161

your amp will do 1000 watts @ 2 ohms

http://www.crutchfield.com/S-pp2adsqp3zv/p_500MRP1000/Alpine-MRP-M1000.html

this is good news, once you get things wired correctly, 

its gona be L.O.U.D.

be careful, you can blow chit up and start fires if your not careful


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## Cruzer (Jul 16, 2010)

how did u set the gain? if u built the box to jl specs its fine. so its a setting, and lots of times its the gain. and it will be

there is no way with the power, and boxes u described that the 12w3 would be in any way louder.

and sealed might sound good, might sound better, but it will NOT be louder than a ported box.


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## NichB77 (Mar 12, 2011)

I'm sorry 60ndown you're right I did wire it at 2 ohms 1000 watts. So you guys don't think it has anything to do with the box and I should just play with the amp settings?


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## NichB77 (Mar 12, 2011)

Is there a specific song that is good to tune to or is any song fine?


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## Cruzer (Jul 16, 2010)

any song is fine, but ideally u want a really low and really hard hitting song to stress the sub. that way u dont set it up to play country really hard, then u play rap and it clips, distorts, or ruins the sub.

if u built the box right, and sealed it up, its likely the gain. where is ur LPF at?


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## pbasil1 (Mar 4, 2011)

Use multiple songs to tune, and use an actual label cd. Not MP3's. You want the best signal quality possible.


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## NichB77 (Mar 12, 2011)

I built the box perfect to dimensions and used wood glue, professional grade acoustical sealant, silicon, and lots of screws to seal it so I should be good there. The lpf is the same as it was when I took it out of the box which is about 150 Hz which is probably most of the problem. Lol. I had no idea it was set that high. I thought stock would've been 0 for everything.


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## 60ndown (Feb 8, 2007)

NichB77 said:


> I'm sorry 60ndown you're right I did wire it at 2 ohms 1000 watts. So you guys don't think it has anything to do with the box and I should just play with the amp settings?


make sure

ssf = set to 30hz

amp set to LOW PASS (not full range or high pass)

speaker wires are connected at amp on correct terminals, there should be some way to tell where the 2 wires connect to 'bridge' the amp for full power, if wires are connected wrong at amp you will only get low power.

gain is at about 30-60% to start.

you will know when you get it right because you have loud bass, until then it wired/settings wrong.


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## Cruzer (Jul 16, 2010)

lpf should really not be any higher than 100hz imo. most use 75/80hz.

other than that, its probably gain setting. its probably way low(just guessing)

bump the gain up just a little, do u notice an increase in output(loudness) and does the sub now sound bad/funny in any way?


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## NichB77 (Mar 12, 2011)

What is ssf? Amp only has a lpf no full range or high pass option. It is all wired right. In my mind it seems right to set the low pass around 50 Hz or maybe even lower, and seing as W6 can supposedly hit at 18 Hz I should be setting the lpf at about 15. Tell me if im wrong because that seems dangerously low to me and I'm fairly new to car audio. I would like to set gain and such but I don't want to be blasting music at 5 and pissing off everyone around, so I probably have to wait until the weekend to truly tune the amp.


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## Cruzer (Jul 16, 2010)

SSF is sub sonic filter. anything below that setting, the sub will not play. if ur using a ported box u want to set it a little below your tuning. so say ur tuned to 32hz, u would want to set it like 25hz. winisd will also tell u where u should set this to not hurt ur sub(cone excursion tab)

LPF cuts off frequencies above the setting. so if u set it for 15hz, it wont play anything above 15hz, which would be useless for a sub. like i said before, set it for no more than 100-125hz, but most use 75/80

see here for what everyone else is using
http://diymobileaudio.com/forum/gen...17034-what-low-pass-frequence-do-you-use.html

can u drive somewhere close by and set it? i have a car wash that is literally a minute and 30 seconds from my house


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## NichB77 (Mar 12, 2011)

I don't see a ssf knob on my amp so im not sure what to do about that. I set my lpf to about 80 which still might be a little bit high but I will lower it more if I need. My bass eq is at +12 and I set my gain in between the second and third marks out of six and the third mark is nom. I live in a really residential area so there isn't anywhere close by I can go or else I would definitely do it.


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## Cruzer (Jul 16, 2010)

u can check here for ways to set the gain. i hope u set them by ear and not by the marks 

Setting Gains - What's your method? - DIYMA.com

not sure what to do with the amp not having a SSF, its used to protect the sub, and for some reason winisd isnt showing if it will exceed xmax or not in your box and power


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## NichB77 (Mar 12, 2011)

I did set it by marks because I don't want to be playing loud in my neighborhood but I will test it at a reasonable volume. Thanks for all of your help.


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## NichB77 (Mar 12, 2011)

Ok I just went and tuned it, pissed off my neighbors real well. I followed the directions in the amps manual which says turn head unit sub setting to max gain to min, turn up untill you hear distortion, turn down until distortion stops, turn up gain, repeat until you get to high volume with no distortion. I played beamer benz or bently (first thing I thought of with good bass on ipod) and got up to volume 17 with .5v gain which is the fourth mark sounded amazing had my car shaking all over the place. Went up to 5th notch and turned volume up to 18 where it usually started to distort and the bass cut out completeley. Turned it down and all went back to normal so I switch gain back to .5v and turned bass setting down on hu so I can blast it. Sounds great. I guess at the 5th mark the system mustve been drawing to much power and so it just started to shut down. Is that right or was it something else?


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## 60ndown (Feb 8, 2007)

you cant really tune a 1000 watt subwoofer while trying to be quiet 

go someplace you can make some noise, be careful not to attract a bunch of thieves,

go somewhere kinda private.

basic instructions are


1. set all hu setting to flat or 0 
2.insert well known well recorded cd, with lots of bass
3.turn hu volume up to about 50% (you should now have music playing in the car quite loud)

4.turn sub amp gain up until it blends well with the music in the car.

5. when it all sound abut right, tweak setting on your hu to make it as good as possible.

your done.

NEVR PLAY LOUD MUSIC NEAR YOUR HOME, YOU ANNOY NEIGHBOURS AND WILL MAYBE GET YOUR SYSTEM STOLEN BY THIEVES THAT NOW WHERE YOU LIVE.


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## 60ndown (Feb 8, 2007)

some amps will shut down if they are trying to get a lot of current and your wiring is not fat enough to supply that much current. you might have to add extra wires or instal fatter ones one day.


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## NichB77 (Mar 12, 2011)

I wasn't being wuiet at all and I went somewhere slightly private so I should be ok. I will try that way to tune after I finish my new wiring that I will be doing probably at the end of this week or sometime next week. The speaker shop who built my box also ran wire which I crappy sound quest 4 gauge but I recently ordered streetwires 1/0 gauge and a streetwires 4 gauge because I plan on runing the 1/0 to a distribution block in the trunk and the the 4 gauge to the amps so my wire should be good after this.


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## Cruzer (Jul 16, 2010)

so is it louder than the 12w3 now?


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## NichB77 (Mar 12, 2011)

Ya it blows away the 12W3 and its also mich cleaner but I've noticed that from the start. Compared to my friends 12W7 its about the same volume the W7 is just a little louder and the W7 hits even cleaner than the W6. Thanks everyone for your help.


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