Sealed Enclosure question

[sm31]

I did quite a lot of searching, but never found an answer (that I understood).

Being the rank amateur that I am, I can't say why exactly, but for whatever reason my ears have decided they like the sound of a sealed subwoofer enclosure. This is a good thing, because my wife will never go for a dishwasher sized Man Sub in the living room... And I have always been attracted to the idea of building my own sub.

My very limited understanding of sealed vs. ported enclosures indicates that as a general rule, a sealed sub will "roll off" (is that the correct term?) at a higher HZ than a correctly ported enclosure. I also understand that ported sub enclosures need to be built to exacting specifications depending on the driver selected. Please correct me if I'm wrong about any of this. I guess I'm over-simplifying a very complex process...

My questions: Do sealed enclosures have to be made to certain volume specifications based on the driver? Assuming I can build a box braced well enough to eliminate most of the resonance, what happens if I build a sealed enclosure 6 cubic feet instead of 3 (using the same driver). Would the increased space help the sub "reach" lower? This is a hypothetical question obviously, because a 6 cubic foot sealed sub is getting beyond "allowed" parameters in my home.

Thanks for helping me on my journey!

 

[j_garcia]

Both box types need to be the appropriate size for the driver's specs. In general, a sealed box doesn't have the extension that a vented one can achieve, though in both cases it depends entirely on what you decide to design. Good luck!

This belongs in the DIY section.

 

[sm31]

Thanks!

Wasn't sure where to post this... Is there any way I can move it?

 

[ParadigmDawg]

I use a big sealed box. It all depends on the driver and how much power you can get to it.

 

[annunaki]

See some of the links in my signature.

 

[sm31]

See some of the links in my signature.

Last night I read all the threads start to finish. Your work is amazing!!

So, needless to say my original questions have been answered. Unfortunately, this leads me to another question.

What should be my stepwise process on a new subwoofer project? My guess is that it would go something like this:

1) Goals for the project.
2) Budget.
3) Size limits on the box, room dimensions, etc.
4) After that I have no idea, and I'm not even sure about the first 3.

What order do these things fall in: Selection of Amp, Driver, and enclosure dimensions? If I select a driver and an amp, is there a nifty calculation I can do to determine the right size for a sealed enclosure, or should I just ask you guys (I like that option!)? Should I start with the driver, then build the enclosure accordingly, then select an amp capable of pushing the driver to desired results?

If all this has been covered before, I'm really sorry. Still trying to find my way around this forum... Thanks again!!

 

[alexwakelin]

I am close to finishing up my first DIY sub, so far it has (mostly) been a lot of fun. I can't wait to fire mine up for the first time. You may have read posts which mention a program called WinISD, which is used to model speaker boxes. It is free to download and a lot of fun to play with. It has a very good built in tutorial, and if you have problems using the program post them here and I'm sure someone will help you out. Other people have also asked nicely and had someone from the forum model the box/driver for them.

You can download it here:

http://www.linearteam.dk/default.aspx?pageid=winisdpro

I would recommend that you just download it and start playing around. Once you get the hang of it you can learn a lot about how speakers work by changing various parameters and see how they affect the response curve, etc.

Once you decide on a budget you can start looking at what driver you think you want to use and model it in WinISD to see if it will work in the enclosure size you want. Good luck, and have fun!

 

[annunaki]

Last night I read all the threads start to finish. Your work is amazing!!

So, needless to say my original questions have been answered. Unfortunately, this leads me to another question.

What should be my stepwise process on a new subwoofer project? My guess is that it would go something like this:

1) Goals for the project.
2) Budget.
3) Size limits on the box, room dimensions, etc.
4) After that I have no idea, and I'm not even sure about the first 3.

What order do these things fall in: Selection of Amp, Driver, and enclosure dimensions? If I select a driver and an amp, is there a nifty calculation I can do to determine the right size for a sealed enclosure, or should I just ask you guys (I like that option!)? Should I start with the driver, then build the enclosure accordingly, then select an amp capable of pushing the driver to desired results?

If all this has been covered before, I'm really sorry. Still trying to find my way around this forum... Thanks again!!

1) Goals for the project.

Great place to start

2) Budget.

Also well needed

3) Size limits on the box, room dimensions, etc

This will help determine driver selection as well as fits into 1 (Goals)

After that, Driver selection (what driver fits budget, goals, size, etc.), Enclosure planning/Amp selection (what best drives the sub), Construction

 

[ParadigmDawg]

Nuff said.......

 

[mustang90]

what sub and box is that? ^^^

 

[avaserfi]

what sub and box is that? ^^^

It's an Audiopulse Axis 15" driver and I made the cab .

 

[sm31]

Nuff said.......

Edit: Looks like someone beat me to the question!

That is truly an awesome speaker! Absolutely beautiful. Did you build it yourself? Do you have any specs on the box? What driver is that? Does it take something as substantial as an EP2500 to drive it?

My room is about 3000 CF. Not particularly large, but the 12 ft ceilings add a lot of volume. There are also 2 largish openings, but I'm getting a surprising level of performance at my listening area from one particular corner (especially considering the source, a sad old Sony SA-WM40). But if I'm not careful it can get boomy.

This may not be a good question given the info I provided, but do you think a sub with the same specs as the one pictured would be a good candidate?

 

[avaserfi]

Did you build it yourself?

I was the designer and builder.

Do you have any specs on the box?

The cabinet is 5 cubic feet made from cabinet grade ply and double thick baffle. The finish is a red oak veneer painted black.

What driver is that?

The driver is an Audiopulse Axis 15. It is a unit of extreme linearity and utmost quality. One would be hard pressed to find a better driver at any price.

Does it take something as substantial as an EP2500 to drive it?

Right now the EP2500 is the cheapest amp that should be used with this driver. Even bridged at 4 ohms the EP2500 produces less than half the ideal amount of power for this driver.

This may not be a good question given the info I provided, but do you think a sub with the same specs as the one pictured would be a good candidate?

The sub pictured would be more than sufficient in your room.

 

[strube]

I was the designer and builder.

Hi Andrew,

I don't mean to hijack the thread, but do you use a CAD program like SolidWorks to do your initial designing, after you have all the necessary parameters figured out?

Then do you use good-old-fashioned woodworking tools (table saw, jigsaw, chisels, router, etc.) or do you have access to fancier things like milling machines or even CNCs and the like?

I haven't done true "furniture grade" woodworking in a long time (back in the high school 4-H days, even ) but I must say, your finish work from P-Dawg's pictures look pretty fantastic. Nice work!

 

[avaserfi]

I don't mean to hijack the thread, but do you use a CAD program like SolidWorks to do your initial designing, after you have all the necessary parameters figured out?

For PDawg's build I just drew it out on a piece of paper. Occasionally I use CAD programs as well. It just depends on how much time I have to build the project.

Then do you use good-old-fashioned woodworking tools (table saw, jigsaw, chisels, router, etc.) or do you have access to fancier things like milling machines or even CNCs and the like?

Table saw, router and sander were all the power tools used on this build.

 

[sm31]

The driver is an Audiopulse Axis 15. It is a unit of extreme linearity and utmost quality. One would be hard pressed to find a better driver at any price.

Right now the EP2500 is the cheapest amp that should be used with this driver. Even bridged at 4 ohms the EP2500 produces less than half the ideal amount of power for this driver.

Wow, a 40 lb motor! I'll keep an eye out for another sale on them!

Thanks again!!!!!

 

[ParadigmDawg]

Dang....I wanted to play too but Andrew answered all the questions....

I don't know if we are allowed to talk about it yet but Behringer is releasing a 4k watt amp later this year so I am jumping up to that. I am also going to add one more identical sub.