Compact Ported Enclosure Advice/Design - SA-12

[Trent Hari 1]

Alright I'm looking for advice on a sub box design for an Sa-12 that will give as much SPL as possible - without sounding terribly peaky. I'm willing to compromise on Spl for a frequency curve that would be acceptable for normal music listening- hip hop, rock, and country.

sub is on JX 1000/1 - if you have questions about my vehicle and setup - look on my profile first under "About Me" and then ask me if the info you want is not there.

 

Member Quentin Jarrell  said "I would build the enclosure 1.75 cubic feet net tuned to 32 hertz.  This will give you a 3db ripple (boost) at 35 herts and give you a F3 (-3db) at 26 hertz.  This will give you the sense of exaggerated bass output.  You can go smaller down to 1.25 feet but keep tuning at 32hz and do not go over 1.75 feet as group delay would be higher than desirable. "

 

So, taking that advice into account, I would appreciate a box design that would stay within my

dimensions designed to these specifications-

 

Dimensions that would be good for me - a wedge- style box - 

 

Material- 3/4" MDF 

Within "constrained by" these dimensions -Its a truck- box type design 

• 7" depth top
• 12" depth bottom
• 16" tall
• 30" long

Tuning and design -wise

• 1.75 cubes NET tuned to 32 hz -
• Of course if it can be made smaller (less volume) without a significant compromise in audio quality or output - that would be great - if not its okay it will fit.
• The port on the left side when looking at the sub would be great.
•  I would like to trim down the length if it can be made smaller 

I would like help with a design that would meet these specifications.

I may even attempt to build this box myself if it is feasible

Edited May 18, 2013 by Trent Hari

[altoncustomtech 773]

If you have access to some average power tools you should be able to build it yourself.  The only difficulty is with angles without access to a table saw they can often prove challenging to get cut exactly right on the width of the board with the angle on it.  I've found it's easy enough to cheat that by making that dimension about an inch wider than required then just trim it down on the 90 degree side flush with the enclosure.

 

Unfortunately now for the bad news.  The dimensions you provided only give a GROSS internal volume of 1.91cuft.  When you subtract from that the .14cuft that the sub will displace itself that only leaves 1.77cuft to work with and even if you were to settle with the minimum 1.25cuft that Quentin said is possible you still can't get a usable amount of port area to fit in that small of a space and the port length is just too long to easily manage in the enclosure properly.

 

You're going to have to rethink your strategy with your sub and it's enclosure if you want it to perform at anywhere near it's optimum potential.  Even going down to a respectable 10" size sub would present a challenge fitting in the available space, it's still going to need to be larger than that to get a usable port size.

 

Hate to give you the bad news, but there's just not enough room in those dimensions to do it right. 

[///M5 2,833]

Indeed. You need to either massage your constraints or sell your 12 and buy a 10.

[Trent Hari 1]

If you have access to some average power tools you should be able to build it yourself.  The only difficulty is with angles without access to a table saw they can often prove challenging to get cut exactly right on the width of the board with the angle on it.  I've found it's easy enough to cheat that by making that dimension about an inch wider than required then just trim it down on the 90 degree side flush with the enclosure.

 

Unfortunately now for the bad news.  The dimensions you provided only give a GROSS internal volume of 1.91cuft.  When you subtract from that the .14cuft that the sub will displace itself that only leaves 1.77cuft to work with and even if you were to settle with the minimum 1.25cuft that Quentin said is possible you still can't get a usable amount of port area to fit in that small of a space and the port length is just too long to easily manage in the enclosure properly.

 

You're going to have to rethink your strategy with your sub and it's enclosure if you want it to perform at anywhere near it's optimum potential.  Even going down to a respectable 10" size sub would present a challenge fitting in the available space, it's still going to need to be larger than that to get a usable port size.

 

Hate to give you the bad news, but there's just not enough room in those dimensions to do it right. 

Alright. Well i guess my other option is to go sealed. I have a shop at my house with a table saw (with tilt up to 45 degrees) and a band saw drill press, wood sander...etc. so tools aren't a problem.

What i have now is 1 cube GROSS ported (tuned pretty high-has a pretty short port)so i'm sure even that box you described would be a significant improvement. 

If you think it would increase output significantly to have a ported enclosure, ill remeasure my truck and see if i could fudge on those dimensions a bit. - tell me how much larger on my dimensions i would need to go for a port to work.

Otherwise, if it's not possible to get a port without being significantly larger, I guess i can look into a sealed enclosure.

 

 Would you think i would lose a significant amount of output by going to a sealed enclosure vs ported or would the output be comparable?

 

I really can't have everything I want , so ill be willing to compromise a little to do it right.

 

I really do not want to go to a smaller sub-woofer unless absolutely necessary. 

 

[pmureika 31]

If you have access to some average power tools you should be able to build it yourself.  The only difficulty is with angles without access to a table saw they can often prove challenging to get cut exactly right on the width of the board with the angle on it.  I've found it's easy enough to cheat that by making that dimension about an inch wider than required then just trim it down on the 90 degree side flush with the enclosure.

 

Unfortunately now for the bad news.  The dimensions you provided only give a GROSS internal volume of 1.91cuft.  When you subtract from that the .14cuft that the sub will displace itself that only leaves 1.77cuft to work with and even if you were to settle with the minimum 1.25cuft that Quentin said is possible you still can't get a usable amount of port area to fit in that small of a space and the port length is just too long to easily manage in the enclosure properly.

 

You're going to have to rethink your strategy with your sub and it's enclosure if you want it to perform at anywhere near it's optimum potential.  Even going down to a respectable 10" size sub would present a challenge fitting in the available space, it's still going to need to be larger than that to get a usable port size.

 

Hate to give you the bad news, but there's just not enough room in those dimensions to do it right. 

Will a aero port use less space?

[altoncustomtech 773]

If you have access to some average power tools you should be able to build it yourself.  The only difficulty is with angles without access to a table saw they can often prove challenging to get cut exactly right on the width of the board with the angle on it.  I've found it's easy enough to cheat that by making that dimension about an inch wider than required then just trim it down on the 90 degree side flush with the enclosure.

 

Unfortunately now for the bad news.  The dimensions you provided only give a GROSS internal volume of 1.91cuft.  When you subtract from that the .14cuft that the sub will displace itself that only leaves 1.77cuft to work with and even if you were to settle with the minimum 1.25cuft that Quentin said is possible you still can't get a usable amount of port area to fit in that small of a space and the port length is just too long to easily manage in the enclosure properly.

 

You're going to have to rethink your strategy with your sub and it's enclosure if you want it to perform at anywhere near it's optimum potential.  Even going down to a respectable 10" size sub would present a challenge fitting in the available space, it's still going to need to be larger than that to get a usable port size.

 

Hate to give you the bad news, but there's just not enough room in those dimensions to do it right. 

Will a aero port use less space?

 

Nope.  I did the calculations using all the way down to the same port area as a 3" aero.  Technically it could fit but it's not even half the minimum port area the sub should have and the port would have to be about 10" longer than the aero kit comes ready to make it up to.  Not that it's difficult to lengthen it, but in all honesty why subject the sub to such sub-optimal conditions.  

 

OP can you measure your MAX dimensions, going to the absolute limit you're willing to give up?  It's not like you need a great deal more volume, just enough to help.

[Trent Hari 1]

Okay i have to go to work- ill be back with the dimentions soon

try a 12*16*30 box and see if that would work

[altoncustomtech 773]

Okay i have to go to work- ill be back with the dimentions soon

try a 12*16*30 box and see if that would work

 

That actually makes a pretty good difference.  1.75cuft NET tuned to 32hz with enough port area to keep the port velocity to 25m/s is definitely attainable at those dimensions.  Funny how a few inches can make such a big difference isn't it?

[Quentin Jarrell 671]

This is per your max deminsions and is a very tight fit but I doubt you would hear any audible difference.  I assumed this is a single cab truck.  Sub behind driver seat with port firing toward driver side (this is best for loading)

 

[gprestonmoto 89]

Okay i have to go to work- ill be back with the dimentions soon

try a 12*16*30 box and see if that would work

 

That actually makes a pretty good difference.  1.75cuft NET tuned to 32hz with enough port area to keep the port velocity to 25m/s is definitely attainable at those dimensions.  Funny how a few inches can make such a big difference isn't it?

That's what she said. *giggity

[jonbearsmt 919]

warning that amp has no SSF

[Trent Hari 1]

This is per your max deminsions and is a very tight fit but I doubt you would hear any audible difference. I assumed this is a single cab truck. Sub behind driver seat with port firing toward driver side (this is best for loading)

(I have 30 hz subsonic filters on the rcas)

Perfect I like the design Quinton. What is the volume on that box? If going larger would help a lot, you can fudge on the 7" dimension.- I have a back seat so I could probably get a 5 cube box back there, I just do more with my truck than listen to music., I would like to be able to remove the box reletively easily if I need to haul people:-)

If you look at my profile, you can see all the details about my vehicle.

Just out of curiosity, does more volume produce better frequency response or output?

Also, I may be building this box myself, so simple is good when it comes to design :-)

Edited May 18, 2013 by Trent Hari

[Quentin Jarrell 671]

It's a hair under 1.25. Larger volume creates a little more output. You wouldn't hear any difference in sound quality.

[Quentin Jarrell 671]

Pm me your email and I can send you the 3d sketch up and you can get all of the deminsions from the model.

[Trent Hari 1]

Pm me your email and I can send you the 3d sketch up and you can get all of the deminsions from the model.

Alright. Thank you for advice. I'm sure ill have a million more questions when i go to build it.

[Trent Hari 1]

Pm me your email and I can send you the 3d sketch up and you can get all of the deminsions from the model.

 

I think i sent you a PM, if you have not received it ill resend it. under my messages, it said the message was not read yet.- i sent it yesterday.

Edited May 20, 2013 by Trent Hari

[Trent Hari 1]

So could i get help with a design for a 17" Tall  x 8" top x 12" bottom x 30" long wedge- shaped subwoofer box tuned to 32 hz (3/4" MDF) for an SA-12?

[Trent Hari 1]

So could i get help with a design for a 17" Tall  x 8" top x 12" bottom x 30" long wedge- shaped subwoofer box tuned to 32 hz (3/4" MDF) for an SA-12?

Can anyone help me with a design?

[Trent Hari 1]

Bump

[Trent Hari 1]

bump anyone?

[Trent Hari 1]

bump

[Trent Hari 1]

Bump

[Trent Hari 1]

Bump anyone again?

[Trent Hari 1]

Does anyone care about helping a customer of SSA build a box for a sub-woofer that was purchased here? Please?

[///M5 2,833]

You've been helped before and then shit on the ones helping.  Add to that you are asking to be spoon fed and resist trying.