Help with a couple box designs

[immageek]

First of all, this is a great forum and some very helpful people around here. Last time I asked for help on a box design, Joe X gave me a great design and it worked out perfect. I totally forgot to put pics in that thread too. I've asked for thoughts and design ideas in other forums and got nothing.

So here goes. I have 2 projects I want to work on, now they are not car related, actually for the home, but pretty much the same principals are the same. The first thing I'm looking at is adding a small sub to my PC. I built some speakers from a flatpack and raw drivers/crossover components and they sound great, just lacking deep bass. So I'm looking to do a 8" sub in a ported or slot vented enclosure. My only requirements is that is isn't wider than 12". I'm looking at the Dayton Audio SD215a-88 speaker and kinda thinking of a tune 30-35hz as I'd like deeper extension. I'm just trying to make a low cost sub. Other people have recommended the Infinty 860w and other subs that cost a lot more than what that driver costs. I'm not looking to shake the earth with this. It's just some music occasionally and gaming mostly. Not used daily or a lot.

The second project is a new HT sub. I'm looking at the Dayton UM15-22 sub and have been kicking around the idea of sealed as I don't have a ton of space to put it, specifically depth, it can't be more than 23" deep. I'd like to go ported/vented with a tune 17-20hz. But I've heard these Ultimax subs want huge boxes, and I don't want that. Others have said to go with a ported 12" instead if the 15 ported is too big.

Any thoughts or comments are greatly appreciated.

[Triticum Agricolam]

For your 8" sub you might take a look at some of Paul Carmody's free box designs. He designed them for the Dayton RSS210 sub but it may work well for others. Here is the link:

http://techtalk.parts-express.com/showthread.php?221133-Whole-buncha-sub-designs-for-the-RSS210HF-4

For your larger HT sub, your room construction will have an impact on whether sealed or ported will work better. Basement rooms with concrete walls will give you a lot more room gain making sealed more attractive. Rooms with stick built walls may be better with a ported sub. That's a pretty simple look at a complicated situation, but its something to think about.

[immageek]

For your 8" sub you might take a look at some of Paul Carmody's free box designs. He designed them for the Dayton RSS210 sub but it may work well for others. Here is the link:

http://techtalk.parts-express.com/showthread.php?221133-Whole-buncha-sub-designs-for-the-RSS210HF-4

For your larger HT sub, your room construction will have an impact on whether sealed or ported will work better. Basement rooms with concrete walls will give you a lot more room gain making sealed more attractive. Rooms with stick built walls may be better with a ported sub. That's a pretty simple look at a complicated situation, but its something to think about.

Thanks for the link. I've looked over the Pony design and it definitely looks cool, I'm not too sure how fun it would be to have to build it with a folded vent, I'm not that good at box building yet. lol

As for HT sub, yeah, there's a lot that can go into picking the design and I totally understand that. At this point, I'm dying to replace my 15 year old boomy 10" sub with something better and goes deeper.

[Triticum Agricolam]

I wouldn't be intimidated by the port layout of the Pony design. Its all straight cuts, the port just takes two more boards and shouldn't present any issues.

For your HT sub, probably just about anything will be better than what you currently have. I'd suggest you decide exactly how big of a sub you can make work. Having a depth limit of 23" isn't too much of a limitation. You could fit a ported 18" sub in that space, it would just be pretty tall/wide. Once you know what your other dimensional limitations are, that will help narrow down what size subs would work.

In my personal opinion, I'd rather have a smaller ported sub than a larger sealed sub. Again this going to be dependant on how much room gain you get, but its a lot easier to EQ out too much low end output from running a ported sub than it is to try to use EQ to boost the low end performance of a sealed sub.

[immageek]

I wouldn't be intimidated by the port layout of the Pony design. Its all straight cuts, the port just takes two more boards and shouldn't present any issues.

For your HT sub, probably just about anything will be better than what you currently have. I'd suggest you decide exactly how big of a sub you can make work. Having a depth limit of 23" isn't too much of a limitation. You could fit a ported 18" sub in that space, it would just be pretty tall/wide. Once you know what your other dimensional limitations are, that will help narrow down what size subs would work.

In my personal opinion, I'd rather have a smaller ported sub than a larger sealed sub. Again this going to be dependant on how much room gain you get, but its a lot easier to EQ out too much low end output from running a ported sub than it is to try to use EQ to boost the low end performance of a sealed sub.

Thanks for all the input. I will definitely think about that pony sub. I'm weird and still kinda leaning towards a traditional cube design and I found out I have up to 13.5" of width available. So something around 1.25 cuft would be easily possible and able to tune low enough I believe.

as for the HT sub, I'm currently in an apartment, on the first floor which is concrete and the walls are pretty decent build. I'm not looking for ridonculous SPL, but would mind if it got loud here and there. Lows is what I'm after without making a huge box. the micro marty box sounds awesome, but I don't have access to a table saw or anything like that and I talked to HD and Lowes near me and they both have been honest enough to say that their rip saws rip the shit out of wood and chews up birch like mad. I'd like to use Baltic Birch for my build instead of MDF. I can get a flatpack sealed cabinet from PE for $60 shipped and that is very tempting. Modelling the UM15 sealed vs ported, the ported seems to be 6db higher 50hz down to about 10hz, where it rolls off sharply, while the sealed extends about 8db higer down to 5. Granted that area isn't heard, only felt, and the material playing that low is next to ziltch. My only concern is that I don't want another boomy sub in my house. My current one is too boomy and I'm afraid another ported one will be the same way, which is kinda why I'm leaning that way, but I always welcome people's input.

[Triticum Agricolam]

I'd really encourage you to go with a ported sub for HT usage. A low tuned port sub really shouldn't have issues with being boomy. I've built a pair of Micro-marty's and they really got down. If the port sub did end up being on the boomy side, its easy to fix with EQ or you could alway plug the port and turn it into a sealed sub, turning a sealed sub into a ported one to get more output usually isn't feasible.

If you aren't feeling up to cutting out your own box, you might take a look at these flatpacks: http://www.diysoundgroup.com/ported-subwoofers-1.html

[immageek]

I'd really encourage you to go with a ported sub for HT usage. A low tuned port sub really shouldn't have issues with being boomy. I've built a pair of Micro-marty's and they really got down. If the port sub did end up being on the boomy side, its easy to fix with EQ or you could alway plug the port and turn it into a sealed sub, turning a sealed sub into a ported one to get more output usually isn't feasible.

If you aren't feeling up to cutting out your own box, you might take a look at these flatpacks: http://www.diysoundgroup.com/ported-subwoofers-1.html

Thanks. Yeah, I was considering getting that Cube15 from DIYSG but between shipping and the price for it, it's as much as the sub. lol. I know I'm sounding petty, but that's 3 times the cost of the sealed and I just can't justify that cost for a few db more. Plus that box is quite deep and I don't have the space for that kind of depth.

I know it seems like I've talked myself into the sealed at this point, and quite honestly, I think I am going to go that route. A 15 sealed is going to be a ton better than my Paradigm PS1000, a 10" bandpass box. Maybe once I get a house, then I get build a ported cabinet.