Call Car Audio Members - Sub Enclosure question

[DiggetyDan]

Warning - this is a non-4runner specific question but I've seen some knowledgeable responses to some other audio questions so I thought I'd ping the group.

I am currently running a JL Audio 10w7 sub with a JL built High Output (HO) vented box. The problem is it is just too darn big, it takes up almost the entire back section, which wouldn't be so bad if it was easy to move. No dice, the thing weighs a ton. I thought I'd be able to live with it but it's getting to be a real hassle after only a couple of weeks.

I am powering it with an Alpine PDX 1000w amp.

I'm trying to decide what my options are.

A) sell the sub and enclosure on CL or Ebay and go with a different set up.
B) remove the sub from the large enclosure and install it in a smaller box.

I really liked the sound of the sub when I had it going in my last set up. This was the first sub I ever had so I'm really not sure if it's the actual sub, or just having a decent sub and amp. While I do play music loud sometimes for me it's more about the quality of the sound, the crispness, the punch, the feel.

Given these set-ups are going for 500-700 on ebay I could probably get a decent swap with the $.

Alternatively I was just at a car audio shop and they had a 10" vented sub box for $99. The guy said since it's vented it should give similar sound.

So I'm trying to determine what I will sacrifice by putting the JL sub into a smaller box. Is it volume but not quality, or both. I've also read that the sub should be matched to the specs the factory set for the specific sub. The guy at the audio store said in a vented set up that doesn't matter as much, true or bs?

Any advice oh wise ones?

pic attached gives you a sense for the size of the box

 

[FactoryRide]

The w7s are fantastic subs. Almost went with that exact setup and amp except with a 12 and not a 10, but I decided to buy some powerbass and poweracoustik stuff do to a custom set up. For that sub the specs requires for a sealed enclosure to be 1.25 cubic feet of air, and for a ported or vented enclosure it asks for 1.5 cubic feet of air. Keep in mind, that is internal air volume. So don't calculate based of the outside dimensions without taking into account the thickness of the material the box is made. Personally you could make a lot nicer box, and out of birch (a hardwood rather than mdf) and tune the box for it to sound wayyyy better then a prefabbed box. If you want to buy another box for it. If you can find one, JL makes a box called the prowedge, but I'm not sure if they sell it box only. I'm pretty sure Andrew (adio3x) runs this sub and box combo.

If you do decide to go the custom route of building it yourself, here is a website that can help calculate sub box designs: Subwoofer Enclosure Calculators, Fraction to Decimal, Parallel, Series, Port Length and Volume Calculators
Also, if you go this route, take your time and do it right the first time.

 

[DiggetyDan]

The w7s are fantastic subs. Almost went with that exact setup and amp except with a 12 and not a 10, but I decided to buy some powerbass and poweracoustik stuff do to a custom set up. For that sub the specs requires for a sealed enclosure to be 1.25 cubic feet of air, and for a ported or vented enclosure it asks for 1.5 cubic feet of air. Keep in mind, that is internal air volume. So don't calculate based of the outside dimensions without taking into account the thickness of the material the box is made. Personally you could make a lot nicer box, and out of birch (a hardwood rather than mdf) and tune the box for it to sound wayyyy better then a prefabbed box. If you want to buy another box for it. If you can find one, JL makes a box called the prowedge, but I'm not sure if they sell it box only. I'm pretty sure Andrew (adio3x) runs this sub and box combo.

If you do decide to go the custom route of building it yourself, here is a website that can help calculate sub box designs: Subwoofer Enclosure Calculators, Fraction to Decimal, Parallel, Series, Port Length and Volume Calculators
Also, if you go this route, take your time and do it right the first time.

Building a box is very tempting. How difficult is it to "tune" it as you mentioned?

Thanks for the advice and link to that site, looks comprehensive.

 

[FactoryRide]

Tuning, for a ported box is based off of the port. Size and widths of a slot port or vent or diameter of a round port and the depths of it. You first want to decide where you want it tuned to. Say you like 33Hz, well with that website it gives you the option to play around with the port sizes to get the right tuning for your needs. It tells you to put in what you think would be ideal sized and then the tuning frequency and it will tell you how deep your slot vent or round port needs to be. Personally I like the look of round ports, but that's my preference. My last pick up, I custom built a box for it. The box was to be ported with 2 cubic feet of air. For it to be tuned down to 33Hz, my port was 3" in diameter and a hair longer then 6.5" deep into the box.

Play around with that website. It has helped me out alot.

Oh and here's a photo of my last sub build. Still haven't gotten around to doing my current one yet.

 

[McGruder]

I really like the performance of my JL Audio 12 inch W3 sub. The suspended enclosure blends better with the speakers, and provides tight, musical bass. I'm driving it with a 300W channel from the 5 channel Alpine PDX-5 digital amp. This system provides very good sound quality without all of the bulk. I can easily move, or remove, the sub when I need all of the cargo space. Sometimes I think about upgrading the Alpine PDX-5 with a JL Audio HD 900.5 for a little increased power across the board, but the Alpine really does bump the sub and provide impressive performance at louder levels.

Audio Setup:
Pioneer AVIC-Z120BT Navigation Head Unit
Alpine PDX-5 75Wx4 RMS 300Wx1 RMS class D amp
1 pr Alpine SP-17S component speakers
2 pr Alpine SP-17C coaxial speakers (1 pair is driven by HU amp)
JL Audio W3 12" subwoofer
Dynamat Xtreme in doors and liftgate

 

[ChipG]

Box Volume Correction

Please note: A box with 1.5 cuft volume does not have 1.5 cuft of volume when you put the sub into it. you have to subtract the subwoofers volume from the box volume and end up with 1.5 cuft of remaining volume. The subwoofer specifications will give you these dimensions. JL has taken the W7s
volume needs into account when designing the ported box you have so, the only way to get a smaller box is to go sealed.

ChipG

 

[FactoryRide]

Thanks for point that out ChipG. I forgot to mention that.

Got some free time today, going to start working on a design for my box. I'm going to try and have some solidworks sketches later tonight. Getting real giddy about it. Had my subs sitting around for over 6 months waiting to get installed.

 

[FactoryRide]

Well, I got to work on my ideas today. My concern was that I originally had a prefabbed box that was for 2 12" subs, and once the box got placed in the back I instantly changed my mind. I knew I wanted custom, but that threw out the idea of running 2 subs. So I wanted to draw up a box based on specifications of the sub just to get ideas down and in real life sizing. So I decided to take it to solidworks and get it figured out.

Well before I set any dimensions in stone I wanted to have an idea of how much room it takes up. Without building the box there isn't much of a way to see that, but I decided I wanted to make a mock-up of the rear of the 4runner.

Here are the pictures from that

Next was to get a rough idea of a size down for the box. For the sub, in a ported enclosure I needed 2 cubic feet of air volume. I played around with the numbers for a bit and ended up with 18" (H) x 18" (W) x 14" (D). That gave me roughly 1.9 cubic feet of air volume. A little off, but with the added airspace from the fiberglassed front piece it will get it close enough. For the port, I wanted it tuned roughly around 34-35 Hz, and in order to achieve that I went with a 4" port diameter x 11" depth. That gave me the 35 Hz I wanted.

Heres a few pictures from the box, the port, the actual subs
Face plate (which this piece will differ. It is getting fiberglassed)

Here is the port

Heres an exploded view of the box

Here is the sub I am using

Here are a few more pictures of the box sitting in the back of my mock-up cargo area

That is pretty much what I plan to do. I may end up making a vanity piece with plexi to cover up the amp and cap wiring but we will see. As far as the finish of the box, I plan to bedliner the box and I may paint the fiberglassed piece that the sub will rest in. Planning to build this here in the next few weeks or so.