Looking for some help with port calculations.

[macisme 10+ year member]

I have built my box for my two solo x 18's which according to the wedge2 specs on the12volt came out to around 34cubes.. before bracing sub displacement and port. Sine around 20 cubes is about max for these subs it leaves me with plenty of bracing headroom and port size. I have walled the 18's off behind my backseat for now and will have my battery rack under the truck.. everything fits and is almost ready for final push on box build, but I need help with port length and size. Looking to tune around 36-38hertz. I have been told our trucks RF is 38 so I would like to stay around that with my tuning. Amps will be two strapped saz3000's jfyi. Ty for any help u can give... measurements are 48w 37h1 35.25h2 38depth with .75 material.

Link to calculator I used

Subwoofer Enclosure Calculators, Fraction to Decimal, Parallel, Series, Port Length and Volume Calculators

Click to read more...

 

[RAM_Designs 5,000+ posts]

So you have the box built...but no port? Easiest thing to do would buy a couple of 12" sonotubes from Home Depot and use those. Regardless, your box is going to be huge...too huge. Also, you probably should have doubled-up on MDF all around the box. Seems like you should have done more planning before starting the build.

 

[macisme 10+ year member]

So you have the box built...but no port? Easiest thing to do would buy a couple of 12" sonotubes from Home Depot and use those. Regardless, your box is going to be huge...too huge. Also, you probably should have doubled-up on MDF all around the box. Seems like you should have done more planning before starting the build.

Lol yea you are right. We did plan it out, however once we got into it a little more some things wouldn't fit and we had to switch the design. Too much airspace can be fixed by adding my 2nd ply inside the box instead of the outside as well as just more/thicker bracing I'm sure. I'm sorry I should have made it known that I was doubling up on the whole box to keep it from flexing when it's all done. I have all the pieces cut, except for the doubling up pieces. I've only built two other boxes so I'm just learning as I go man, so any advice you can give me is greatly appreciated. I am just looking for suggestions on port sizes etc. after I get my bracing in and account for sub displacement I will probably get more into the port design, since I'll have a better idea of the air space I'll be left with. I'm not very good as designing things, only changing them on the fly and making things more difficult lol.

I am looking to make it around 36-38 hertz, do you think that's a decent tuning for these subs? I am wanting to try and pull hair tricks, even if they aren't much of one at all...

 

[macisme 10+ year member]

BTW I checked out your site.. Those are some AMAZING designs bro. I wish I had your knowledge and skills in design lol

I think I'm going to trim down my box quite a bit... what do u think I should shoot for before bracing etc in cubes?

 

[RAM_Designs 5,000+ posts]

BTW I checked out your site.. Those are some AMAZING designs bro. I wish I had your knowledge and skills in design lol

Thanks man, I appreciate it.

As far as the tuning goes. I think 34-35hz would be better, especially since you want to do hair tricks and peak at 38hz(box efficiency peaks around 3-5hz above the tuning frequency).

 

[macisme 10+ year member]

Just remeasured and came up with 48w 35.5h1 22h2 34depth.. The reason I don't have a port btw is because all of the pieces for the box aren't yet cut.. I still need to get my front pieces cut which is why I am looking for idea's on a port so I can go ahead and cut those pieces //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif With the new measurements It puts me just under 24 cubes and after I do all my bracing, and factor in the sub displacement I can easily get rid of anything extra now //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif I want to thank you though for making me remeasure everything because I have been using the original measurements that we had to redesign from. If you hadn't questioned it I would have messed up a lot lol. I knew there was something funny sounding about me having over 30 cubes in the back of this truck lol I just need to cut one piece down that is already cut and we should be pretty good. TY again even though you unknowingly helped me haha. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

* just read your post* Sounds good. I have a message saying pretty much the same thing you just said. You guys seem to be pro's at this and I will take your word for it without question //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[RAM_Designs 5,000+ posts]

Just remeasured and came up with 48w 35.5h1 22h2 34depth.. The reason I don't have a port btw is because all of the pieces for the box aren't yet cut.. I still need to get my front pieces cut which is why I am looking for idea's on a port so I can go ahead and cut those pieces //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif With the new measurements It puts me just under 24 cubes and after I do all my bracing, and factor in the sub displacement I can easily get rid of anything extra now //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

If you're planning on doubling up the MDF, you're looking at just 20.8ft^3...now you're looking at too small of a box after you count sub/port/bracing displacements. //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

 

[Buck 5,000+ posts]

You usually figure out everything before you build the box. Like ram said, it's going to be easiest just to put aeros or sonotubes. But I would start over and do it right, especially with that kind of equipment.

 

[RAM_Designs 5,000+ posts]

Actually, cut a couple of 10" sonotubes 13" in length and you'll have ~18ft^3 with a ~34hz tuning depending on how much bracing you use.

 

[maljr1980 10+ year member]

Did u say 34 cubes for 2 subs

 

[T.I.K. 10+ year member]

Did u say 34 cubes for 2 subs

obviously not, you might as well run them IB if you do that, lol

 

[macisme 10+ year member]

If you're planning on doubling up the MDF, you're looking at just 20.8ft^3...now you're looking at too small of a box after you count sub/port/bracing displacements. //content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

Most of the doubling up is taking place outside of the box dimensions. I'm only going to double up inside the box for like 1 piece on the front baffle lol all the rest is on the outside of the second dimensions I listed //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Like I said earlier.. I can always take away airspace later if it's too much, if it's too little im screwed. When I get into the internal bracing I can have a much better idea on how much bracing these things will need, and just go from there. I'll look into those sonotubes too. Thanks again. I know its frustrating dealing with noobies and our goof ups, but it's much appreciated when we can actually get advise/tips from experienced guys such as yourselves.

 

[macisme 10+ year member]

Did u say 34 cubes for 2 subs

Yes I did, I was using a designs dimensions that was meant for the trash. I thought something seemed off and after I had talked to ram I went over it all again and noticed what I had been saying lol. I've been frustrated with the rain, my help, and just how everything on this **** truck likes to get in the way. I'm learning as I go and it's pretty much the hard way so far. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif I almost have it just right. We'll see in the end.

 

[hispls 5,000+ posts]

obviously not, you might as well run them IB if you do that, lol

Same cone area as 4 15's..... really 34 cube less a huge *** port is big, but hardly out of line.

My 2 cents on this is that walls seem to be very hard to guess on paper and then have it come out tuned as you planned first try.

I like the sono tube idea myself, but the point is you should plan to at least temp it out some way that will allow you to modify port width and depth easily. EVERYTHING should be minimum double walled, including the port wall (if you do slot port) and brace the hell out of it. Just the weight of the solo X would demand 2 to 3 layer baffle.

 

[T.I.K. 10+ year member]

Same cone area as 4 15's..... really 34 cube less a huge *** port is big, but hardly out of line.
My 2 cents on this is that walls seem to be very hard to guess on paper and then have it come out tuned as you planned first try.

I like the sono tube idea myself, but the point is you should plan to at least temp it out some way that will allow you to modify port width and depth easily. EVERYTHING should be minimum double walled, including the port wall (if you do slot port) and brace the hell out of it. Just the weight of the solo X would demand 2 to 3 layer baffle.

About the weight, I'm surprised i haven't seen more "big woofer" builds use a 2x4 to brace up the 80+lb motor some of these subs have