ajusting enclosure volume

[stones 10+ year member]

I want to take a big peice of 2inch thick styrofoam insulation and cut 4 2x10x11inch peices to reduce the volume in my sub enclosure. The enclosure is a dual 1.25cft box for 2 12inch subs, i want to glue the 2 styrofoam peices in each chamber to reduce the volume to 1.0cft per sub.

Question is- Will the styrofoam insulation be effective in filling up the extra airspace?.

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[mrray13 10+ year member]

it should work,get a high "r" rating and it won't be as porus. the only thing though, it is insulation and will keep heat in the box. the subs won't be able to dissipate the heat as well.

 

[adamawayfrommpa 10+ year member]

I think that it would work for a while but won't your subs shake the foam lose or at lest break off little pieces of it over time...

Adam

 

[mrray13 10+ year member]

insulation foam is HDF(high density foam). while the subs may(probably) eventually(use liquid nail) shake it lose, it won't break off pieces of it. anyway, you could use screws to hold it(with washers) to the box.

 

[zane 10+ year member]

Why styrofoam?

Just use MDF and layer it until you reduce the volume.

Dropping the extra .25ft^3 really isnt going to make a whole lot of diffenece sound wise, however, if you are set on it, Use MDF and seal it to the enclosure with silicone.

take it easy,

-zane

 

[stones 10+ year member]

Thanks for the answers guys, I appreciate it.

Im using 2 MTX thunder 8000's and I find that they sound really "boomy' with 1.25cft per sub, I want to tighten up the bass so it mixes with the mids and highs better, right now the subs sound like their playing in the car beside me( really low and boomy but no definition).

I was considering the stryrofoam because its cheap, light and easy to work with but if wood is the best way to go, then i'll use that.

What are some suggestions on how much volume to displace?, MTX reccomends 1.0cft for a minimum size, but that doesn't take into account the transfer function of my car. The car the subs are in is a 1990 chev cavilier z24 with the box in the trunk facing the tail lights. Whats the best SQ sealed size for these MTX's in my cavilier?

Thanks in advance-Stones

P.S.-I would go and ask the local installers around town, but they just don't have a clue about anything, there's not much of a market for car audio in Saskatoon so any existing installers are inexperenced and underpaid.//content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[Unregistered]

whaddaya think?

 

[ITSAV6]

//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Try facing your box in different directions,equalization,adjusting amp gain,etc. before messing with the box. If you have to reduce the volume ,why not take one side off,cut off the amount needed to reduce the volume and replace the side? Just my .02. Good luck!

 

[stones 10+ year member]

facing the box foward sounds bad, I lost all my low frequency response when I tried that( It was still there, but the frequency waves didn't have enuff room to make themselves audible).

Basically the subs sound good to the average listener, but Im picky, I like high definition SPL. I'm not happy unless the bass is mixing with the mids and tweets just right, I tried my dual 1.6cft enclosure, and the subs sounded really, really boomy and loud, which was cool, but not adaquate for daily driving when I switched to the dual 1.25cft enclosure the subs started to behave better but they are still not there yet.

What I want to know is how small should I go? I have 500watts rms going to each sub with the xover set at 80hz.

Throw me a bone here boyz.-Thanks

 

[imral3 10+ year member]

before you go cutting up your box... i would suggest you buy/build a 1.0 cf box. you might find you don't like the sound of a smaller box and will have the option of the 1.25 box still. what amp are you using? is there a bass boost knob? if so, turn it all the way down and adjust up from there.

 

[B&R Innovations]

Just get a saw and make a tester box. ITs NOT hard, god **** people are lazy...you can build a box pefectly, and carpeting isnt hard...just put some thought into it

MDF would work fine if i made it. but yea it will come off, layer it on the bottom and the back edges, liquid nails should hold

 

[ramos 5,000+ posts]

Why not try putting a brick or two inside your box. Measure the brick and see how many it would take to equal .25 cuft. That way you could find out how it would sound. And if you didn't like it you can take the brick(s) out. If you like the way it sounds you can use the more permanent MDF way. Just a thought it worked for me //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[stones 10+ year member]

Thanks for the input guys.

I don't want to chop up the box because it fits in the trunk perfectly as is and looks good, so I would much rather just take up some space inside the the chambers, and im not a big fan of bassboost(pioneer 730 head unit and a Concept CCD1200 sub amp)

RAMOS-I like your idea and im going to try it, I'll add bricks in the box and give it a listen and when I find the right amount of displacement, I will secure the equivilent volume of mdf in the box with screws and silicone adhesive.

As for you mr B&R INNOVATION, do you think all car stereo consumers and hobbie'st are stupid, wow, you actually come in here and suggest that im lazy and stupid for not wanting to build another box, first off, I don't think my land lord would appreciate me setting up a woodshop in the middle of my living room and second, what should I do with the original custom built, vehicle specific, 200 dollar subwoofer box, shove it up my ass? I don't think so. The consumers out in the marketplace have somthing called a BUDGET, you save up so much money and go over to your local retailer where you aquire amplifiers, subs, mids, tweets, headunit and install, in a perfect world this would be easy except for the retailers 100% markup, crappy install skills, and 3rd rate refurbished junk not to mention their grade 7 education.

I have my stuff and I have to make it work on my own, why? because shop owners like you give crappy tech support " OOh you need this and it will only cost 400 bucks" screw you, you guys act like the 5000 bucks that I spent on the equipment is a favour to me, learn some appreciation and respect for the people who make everything you have possible.

 

[mrray13 10+ year member]

don't forget shop owners and sales people who frown on ya when your shopping around and asking questions. most feel as if you don't spend money EVERY time you wlk in the shop ,then screw you. i'm learning as i go , from the forum here and shops that will talk to me. i'm building my system a piece or two at a time,and am trying to live within a set (by wife) budget.and space.

oh yea, i'm lucky enuff to have a grandpa with a woodshop, with just about every wood working tool under the sun. i also have a father-in-law who has 25 years of bodywork under his belt. does that mean i have the money( or time) to go buy a stack of MDF, or fiberglass, and make a crapload of boxes? not hardly. so lay-off when someone tries a easy,hopefully, time and money saving way of experimenting. then, can adjust and adjust again to get it set right. then build a permenant box.

ramos, good idea. stones, i hope it works. good luck!!

i'm done.

 

[stones 10+ year member]

Thanks mrray, I appreciate the support, but now that I think about it,. I think I was a little harsh with my little rant and I would like to officially say that I went a little overboard on B&R INNOVATIONS, I have no idea how he runs his business and I don't think I should be so quick to judge him.

BUT I still beleive that alot of retailers are giving their customers a bad deal, I have had countless bad experiences in my home town with greedy car audio shops that sell you bad equipment, do bad installs and markup their products by around 100% AND will not give you the time of day when you ask for technical advise or support. Something must be done about this crap, its just not fair to the consumer.