I bought 2 JL Audio 12W1v2 subwoofers last week and needed a enclosure. Been trying to find one around town pretty cheap and close to exact requirements for the recommended cubic space for a sealed enslosure which is 1.25 for these. I couldn't find anything anywhere close. I only wanted to spend $60.00 max for a box so I went to the flea market in town and the guy had 0 dual 12" enclosures. I found 1 left at a Audio store near me called Audio One. The volume in it is 1.4 per chamber. The audio guy told me I would be just fine and to put about a 1/4 of poly-fil in each chamber. Now, the 1.4 does not include the driver displacement and size of the bottom of the sub after it is installed. So, I think after adding that into account I will be just fine cause I didn't want to lose a lot of the bass sound I got from the ported enclosure I had after I go to sealed. Was the audio guy correct? Adding Poly-fil will help decrease the size of the chambers? I'm a little worried that I might have made a mistake. It's a great quality done box compare to what I was looking at on Ebay but that one I was looking at was $40.00 less and had a 1.3cu foot size. I just want to make the right decision about the enclosure. 
The poly fill will make the woofer "think" its in a larger enclosure, so the frequency response will be lower and it also helps cancel some unwanted internal resonance. But actually does subtract some of the volume from the box.
I prefer to use carpet underlayment foam for my boxes, its more dense and allows the box size calculation to be more accurate. I glue it to the sides with the same glue they use to attach it to the concrete foundation. That glue doesn't break down the foam, so it stays attached firmly to the box sides.
I prefer to use carpet underlayment foam for my boxes, its more dense and allows the box size calculation to be more accurate. I glue it to the sides with the same glue they use to attach it to the concrete foundation. That glue doesn't break down the foam, so it stays attached firmly to the box sides.
Flyin11 said:
Haven't tried them yet cause I'm still waiting on the speakers to be delivered...Hopefully around Tuesday or Wednesday
I might look into that....It's just the regular foam padding for carpet like in your house?
Yeah, and they have different thcknesses you can get. It is chopped recycled looking stuff with mixed colors.
I'm figuring this...Box is 1.4 cubic ft per chamber...The Displacement of the Driver of the sub is listed as 0.035 cu. ft...So:
1.400 Cu ft - 0.035 cu ft= 1.365 cu ft...Rounded off, 1.37 cubic ft.
There speaker page says 1.25 cu ft for a selaed enclosure (thinking this is the minimu size)...After speaker is in, it will be 1.37...That's a difference of 0.115 cu ft. Which I don't think that's a lot to worry about. It will probably give me a bit more bass response.
Anyone know what 0.115 cu ft. is in inches? I'm thinking about trying some shipping foam from my old job to maybe knock it down to required specs...
1.400 Cu ft - 0.035 cu ft= 1.365 cu ft...Rounded off, 1.37 cubic ft.
There speaker page says 1.25 cu ft for a selaed enclosure (thinking this is the minimu size)...After speaker is in, it will be 1.37...That's a difference of 0.115 cu ft. Which I don't think that's a lot to worry about. It will probably give me a bit more bass response.
Anyone know what 0.115 cu ft. is in inches? I'm thinking about trying some shipping foam from my old job to maybe knock it down to required specs...
I got something similar to this type of foam from my old work tonight but it's thicker:
http://cgi.ebay.com/40-Sheets-of-fo...ryZ41200QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Wanted to try and use maybe 2 pieces of it...Just stuff into the hole and to the back. Wondering if the sound will still bounce off of it and sound good or will it get absorbed and sound like junk? I guess I'll probably just have to test it out and see. Found a page on the net where they were showing people's subs in action and one guy had a pair of 12W3v2 speakers in a 1.7 cu ft box and the specs say 1.25 for them as well. So I don't feel too worried now as if it worked for him it just might for me as well...
http://cgi.ebay.com/40-Sheets-of-fo...ryZ41200QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Wanted to try and use maybe 2 pieces of it...Just stuff into the hole and to the back. Wondering if the sound will still bounce off of it and sound good or will it get absorbed and sound like junk? I guess I'll probably just have to test it out and see. Found a page on the net where they were showing people's subs in action and one guy had a pair of 12W3v2 speakers in a 1.7 cu ft box and the specs say 1.25 for them as well. So I don't feel too worried now as if it worked for him it just might for me as well...
Flyin11 said:
as far as i know, inside the box you don't want the sound to be bouncing off of the walls and cancelling out the sound of the woofer. these are called standing waves. some people try to avoid this by building a box with odd angles included to diffuse the stading waves inside. others use fiberglass insulation, wool, polyfill, and other paddings or even spray on sound deadening to change the sound of a box. you can experiment with different ammounts of material until you get the desired sound. the old rule of thumb used to be 1 pound of polyfill for every one cubic foot of air space. more polyfill will make a box that is too small for a given woofer appear larger. you can use this for up to a 40% increase in air space from what i'm told. don't use too much or it will affect the cone movement or be too compacted and overheat your woofers. it must be somewhat loosly packed into the box. you can find polyfill very cheap at any fabric store or walmart.
you may want to use a solid object (like 2x4's as braces) to make your box smaller or you might try it the way it is. i think it is better to have a slightly larger box that one that is too small. just my opinion. deeper bass in some cases.
Yeah...Stuck them in last night. Forgot to grab the foam pieces so didn't put them in and left it be. It sounds very loud but I didn't notice too much difference in the wattage that was being put out after I paralleled the 4ohm speakers to make a 2 ohm load. Not sure where the extra 180watts went but it still did hit pretty hard. Maybe I need time for the subs to break in. I never paid any attention to that stuff about playing them with low volume for like 16hours before you crank them. Just my experience. Yes, they sound a lot better later and do hit harder later on but if I'm putting speakers in, they are to be played loud right away, not for another 2 weeks or something. Maybe it needs to get use to the enclosure as well? Not sure...I turned the gain on the amp up slightly and noticed a good difference when I went out during lunch today. Will see how it sounds cranked and when I'm going home I just need to do some tweaking with the amp to probably get it right now. Still thinking about the foam as a option though....
I just need to do some tweaking with the amp to probably get it right now. Still thinking about the foam as a option though....I know this is a old thread but I just tried the foam yesterday like I was talking about and just took the pieces of it and wrapped in a little bit of Polyfil to try and maybe have it hit a little harder and change the frequency but the results aren't what I was looking for. It doesn't sound bad but it kind of took away from the loud bass response of the bass guitar I had before and made it sound less punchy. It was a little bit more punchy on the kick drums but I love hearing the bass guitar lines hit in my legs up front and all so I'm just going to take it out and leave it be. Atleast I know now that it wouldn't be the sound I was looking for with it in it and I wouldn't be wondering myself to death about how it will sound. Oh well, live and learn and it only cost me about $4.00 for the Polyfil....
The fill will do about the same thing as your slightly larger box does, just drops the curve a little and damps a little of the highs out. Best thing is to play with it though, you don't like it so its better empty and now you know. With the 1.25 box it may have helped, maybe depending on what you like. I'd guess a slightly larger than spec sealed box with little or no packing would be closer to a ported box though. Being larger gives more bottom, not a problem unless you thrash it really hard as it may lessen power rating a hair....if you get it to topping out. Standing waves are worse in a square box, that is why most are not square on all sides. Then again with a sub it is not that big of a problem.
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