I have a JL 10w3v3 sub. The problem is that the enclosure i'm using for it is a formerly 8'' enclosure custom made for my 2001 sentra. The installer told me that i could use this encosure if we made it a 10'' which we did. Now i'm afraid the box is too small. After doing a research i've found that if the enclosure is too small the sound could be affected and so does the sub.(right now the sound is pretty decent but sometimes it lacks presence) JL recommends a .625 enclosure (sealed). Should i get a .625 box? how important is that my box is exactly the size JL recommends? Is poly-fil an option? thank you. i could send a picture if it helps.
I don't know how small your box is, but the volume of the box plays a critical role in how your sub will perform. The larger the box becomes, the deeper the sub will be able to play. The downside is the bigger the box is, the less power the sub can handle. JL recommends a .625 box size as a compromise between deep bass extension and high power handling. You can go larger (which i usually prefer) or smaller than they recommend. Your sub will surely work in a smaller box, but if the box isn't large enough you may find you get deeper bass with an 8". Poly-fil can make some difference. It adds mass to the air inside the box, making the sub sound as if it were in a larger enclosure. Figure about a 10% increase in box volume when filling it with Poly-fil. A box that is .5 cubic ft would act as if it were .55 ft. That's not a big difference, but it does help.
I'd rather have too big than too small. You can always add ballast if you feel like the sound isn't where you like it. Or you may feel like you wish the sub could go a little deeper, and add some poly-fil to make it sound even larger. If the box is a good fit for your car, go for it.
To explain the concept of ballast: what you are concerned with is the interior volume of the box - so you can always add/glue wood blocks or similar into the box to build a false wall or take up space to make the box internal volume smaller.
Hope This Helps!!!
2002 Ford Focus Sony CDX-GT410u Sony XT-100HD HD Tuner Stock speakers, no amp, no subs
I could swear i just answered this, but if the box is a good fit for your car, i would go for it. You can take away from the volume of the box by adding ballast if you think the response isn't quite where you'd like it. Ballast is anything that takes up space, but its wise to use it to add additional bracing to the enclosure.
J Ro:I could swear i just answered this
You did - but I hadn't heard it referred to as ballast, so I was trying to clarify it for the original poster.
Change the sub enclosure for a sealed 12.5 x 12.5 x 12.5 and what a difference. This was the sound i was expecting from jl w3v3. Thanks guys so much. You rock!!!