Someone School me on boxes

[GrandPrixAlpine 10+ year member]

Someone school me. Im want to start building enclosures but i need to learn much more before i start. i know nothing about the tune of the box or anything. i get the port to no port thanks to the stickie up top.

My test run will be with my Memphis M-Class 10" Subs Im going to do a single and a Dual enclosure

2.00 / 38 / 10.5 x 1.25 x 17 those are the specs direct from memphis.

All i get out of that is it needs to be 2.00 Cubic Feet with a port that is 10.5in Front to back by 1.25in witdth by 17 side to side

Click to read more...

 

[Kangaroux 5,000+ posts]

instead of doing 2 different enclosures you can make a dual enclosure but do separate chambers, will save you time and money. i suggest downloading sketchup to do designs in as it works great.

alternatively if you hit up ram_designs and have him design a box for you, it comes with a screenshot of the model in sketchup with all measurements. im sure he'd be more than happy to give you a quick rundown of how he went about designing it. its not a hard process, but you need to crunch some numbers repeatedly to get the right results

 

[GrandPrixAlpine 10+ year member]

i want to learn how to do it myself. i could easily just have someone else design something for me but id rather do it myself.

 

[GrandPrixAlpine 10+ year member]

View attachment 26525026

This is what i have so far. From the research ive done on here the inside edges should have those slants in them to reduce dead spots right? I went with an L port instead of a S port for simplicity. But how to i get the dimensions of the box so that i get the 34hz per side? Forgot to mention im going to use .5" MDF. Also would there be any benefit to painting the MDF to a Gloss Finish on the inside as im going to on the outside?

 

[Buck 5,000+ posts]

If you need a designer...

But if you have any specific questions you can email me. It's hard to school someone, because when you start explaining you wind up having to explain 10 things to explain that 1 thing.

 

[brandinooooo 10+ year member]

View attachment 26525026
This is what i have so far. From the research ive done on here the inside edges should have those slants in them to reduce dead spots right? I went with an L port instead of a S port for simplicity. But how to i get the dimensions of the box so that i get the 34hz per side? Forgot to mention im going to use .5" MDF. Also would there be any benefit to painting the MDF to a Gloss Finish on the inside as im going to on the outside?

If that one side is tuned to 34 then the same thing on the other side would be at 34.

The slants help the air flow and add some strength to the box

 

[Frito11 10+ year member]

View attachment 26525026
This is what i have so far. From the research ive done on here the inside edges should have those slants in them to reduce dead spots right? I went with an L port instead of a S port for simplicity. But how to i get the dimensions of the box so that i get the 34hz per side? Forgot to mention im going to use .5" MDF. Also would there be any benefit to painting the MDF to a Gloss Finish on the inside as im going to on the outside?

i wouldn't use anything less than 3/4" MDF unless its a really small box or not for a subwoofer. the large surfaces in a box can and will resonate at the right frequency inside the box and when that happens you loose SPL and quality of the bass in general along with it, if it resonates really bad at a certain freq you could destroy the sub as well.

a lot of people also double up the baffle (panel the woofers are on) so its 1.5" thick as well to help eliminate any movement that the subwoofer may induce on it when its playing at high volumes.

i looked up your sub on Memphis's website because that box volume sounded too large for 1 10 and too small for 2 10's if your doing separate chambers for each sub what you want to shoot for is 1.65 cuft / 38 hz according to

http://www.memphiscaraudio.com/documents/Updated%202010%20Enclosure%20Recommendations.pdf

even that is pretty big for a 10 IMO but should sound good. you don't want to build too big a box cu.ft wise internally because if you do the sub will not be able to operate correctly because there is not enough dampening from the box. in my experience its always wise to stay pretty close to or under what the mfg says the maximum size of the box should be. port tuning can be changed to preference really as long as you don't go crazy with it. for a vented 10 38hz is probably as low as you would want to go anyways.

good luck with the design and keep us posted

 

[GrandPrixAlpine 10+ year member]

i wouldn't use anything less than 3/4" MDF unless its a really small box or not for a subwoofer. the large surfaces in a box can and will resonate at the right frequency inside the box and when that happens you loose SPL and quality of the bass in general along with it, if it resonates really bad at a certain freq you could destroy the sub as well.
a lot of people also double up the baffle (panel the woofers are on) so its 1.5" thick as well to help eliminate any movement that the subwoofer may induce on it when its playing at high volumes.

i looked up your sub on Memphis's website because that box volume sounded too large for 1 10 and too small for 2 10's if your doing separate chambers for each sub what you want to shoot for is 1.65 cuft / 38 hz according to

http://www.memphiscaraudio.com/documents/Updated%202010%20Enclosure%20Recommendations.pdf

even that is pretty big for a 10 IMO but should sound good. you don't want to build too big a box cu.ft wise internally because if you do the sub will not be able to operate correctly because there is not enough dampening from the box. in my experience its always wise to stay pretty close to or under what the mfg says the maximum size of the box should be. port tuning can be changed to preference really as long as you don't go crazy with it. for a vented 10 38hz is probably as low as you would want to go anyways.

good luck with the design and keep us posted

You missed part of the memphis page, there is a minimum box size and a optimum.

Min Op.

1.65 / 38 / 10.5 x 1.25 x 16.75 2.00 / 34 / 10.5 x 1.25 x 17

No one has really answered my question though. how do i find the lengths to get 2.00 cubic feet and still acheive 34 hz

 

[fasfocus00 5,000+ posts]

You missed part of the memphis page, there is a minimum box size and a optimum.
Min Op.

1.65 / 38 / 10.5 x 1.25 x 16.75 2.00 / 34 / 10.5 x 1.25 x 17

No one has really answered my question though. how do i find the lengths to get 2.00 cubic feet and still acheive 34 hz

someone failed algebra 1?

 

[GrandPrixAlpine 10+ year member]

someone failed algebra 1?

as a matter of fact yes i did

 

[fasfocus00 5,000+ posts]

as a matter of fact yes i did

you are going to want someone to design your box for you than. building and/or designing boxes requires proficiency in both algebra 1 and geometry.

 

[GrandPrixAlpine 10+ year member]

you are going to want someone to design your box for you than. building and/or designing boxes requires proficiency in both algebra 1 and geometry.

I sure can try though if someone would explain the fourmulas.

 

[GrandPrixAlpine 10+ year member]

So using the stickey at the top of the page these are the numbers i got.

Net Vol= 2.00

port area= 10.5 High X 1.25 Wide X 17 Depth

Tuning=34Hz

Desired Width Per Side=20in

Height=10.5 (i think thats right, is it supposed to be the same as the port height?)

Depth=S

Port Length=20.87

Port Displacement= .25362847

Internal Gross Vol=2.55

S=144.47 (doesnt seem right to me)

 

[Frito11 10+ year member]

15-MCP10D4
min. 1.10 / 44 / 10.5 x 1 x 16.5

opt. 1.65 / 38 / 10.5 x 1.25 x 16.75

once again straight from memphis' website. this is space per sub ovc

 

[GrandPrixAlpine 10+ year member]

once again straight from memphis' website. this is space per sub ovc

I dont know what i found then cause i got mine from there too.

http://www.memphiscaraudio.com/documents/Mid2009%20Consumer%20Enclosure%20Recommendations.pdf