Need confirmation and modeling help - noob DIY sub

[GSM]

Ok, been a lurker around the boards for years. 5 years ago I was just about to pull the trigger on dual tempest (sbb4 design) but a few things came up (another kid, new house, etc....) I ended up getting a SVS pcplus 20-39. Love the thing and even upgraded the driver within the last 6 months. Old driver blew because I pretty much run it at it's limit and I have no control. The SVS is in the HT room in the basement.

Well, I've decided I need a sub for upstairs and I've decided to try the DIY approach.

Below are some of my constraints or as I like to call them, project challenges.

1. cheap ~ $250 or less on parts not including enclosure. This is a 'trial' for me to see if I like diy subs/speakers and/or the results. If everythings goes well, which i believe it will, I plan on making dual subs to replace the SVS. With a whole new set of constraints er uh i mean, project challenges, but waaaay more budget and size

2. 100% music only - country, teen pop, whatever else the wife and kids listen to. Since this is 100% music only I'm guessing I can tune this much higher then is normally done around here. 25hz? 30hz? I'm guessing 35hz is too high?

3. room is open to the entire house - 4500 sqft house sooo like i said the room is 'open'- that being the case I'm trying to squeeze the most performance out I can. I have no 'issues' doing a ported design. It'll just make more mdf dust.

4. limited floor space - i figure i can do a 16 inch sonosub - but in this case i think it'll be sacrete(sp?) because rule #1 (cheap) says I can get a 4 foot tube at Home Depot for around $10. That gives what? minus driver, port, double thick MDF on the end.... around 4 ft^3?

5. I'm pretty handy. I have all the tools but, will have to get a circle jig. So now I have an excuse to get a circle jig.

Now, i've been keeping an eye open for sales and found PE is having one now.

PE 300-804 240watt plate amp for $99 (no boost)
PE 295-464 Dayton 12" reference HF subwoofer for $119
PE 091-1245 Dayton BPA-38G HD Binding Post Pair Gold $6

throw in shipping at we're at my limit.

ok, now's here the part where I rapid fire the noob questions. stay with me please.

Any other hardware suggestions I should look at? maybe the PE 15" DVC? I could squeeze that into at 16" tube. I realize my budget is extremely limiting.

Although thinner then sonotube that sacrete tube still seems pretty tough. Has anyone used that before or tried and failed? I guess I could be that person it is only $10

If the consenses is the two above PE parts (on sale) I'll definatley need some modeling help. For some odd reason way back when I could use winisd and understand what it was telling me (at least I thought I understood) Now I can plug the numbers in but dont' see much difference when i compare different drivers. In any case I would appreciate it if someone could run the numbers to make sure group delay isn't bad or port velocity isn't too high or if I have enough power, what you think woudl be the best tuning, 25, 30,35? etc... in a nutshell, what would you do if you were me.

questions about the amp. does it have a built in subsonic filter? is it adjustable (changing resistors)? since this will be at a higher tune and ported I'm looking for some type of safe guard (no, i have no self control, I've already established that) Also, this is going on a receiver with no sub out so I'll have to use high level inputs. Is that going to cause any issues?

Oh, the speakers they'll be matched with are garbage. If the sub turns out good I plan on doing some speakers next.

Ok, I see I have rambled on way to much. I'm just trying to provide as much information as possible. Any suggestions are appreciated. I'll be posting this on several different boards so you only have to respond in your favorite.

thx
Geoff

ps. sorry, no cliff notes

mods, if I've broken any forum rules or mentioned something I shouldn't or offended anyone, it was not intentional. Seems like you can't swing a dead cat without breaking a rule or offending someone any more.

[ThomasW]

My suggestion is to save your money. When you have enough to build a worthwhile sub invest your time and money.

Why?

The room/space is WAY to big for a 12" modest Xmax driver and smallish power amp like those you've listed.

You'll build the thing then you or the kids will turn it up and poof! either the driver or the amp will be destroyed. (The "lack of control" that destroyed the SVS driver is a give-away here, since none of the drivers listed are close to the quality of the SVS driver you toasted.)

FWIW, The tube from HD is worthless. Tube subs should be built from a real concrete forming material like Sonotube (it's a brand name) not the flimsy Quickrete stuff.

My recommendation is to revisit this idea when you've got $500 or so to invest. Then there is equipment worth buying and building with that you'll have a bit more trouble destroying.

[---k---]

A Shiva-X is only $165. Gives a bit more xmax. Can handle more power than that plate amp, but if that is your budget...

Thomas, I would probably typically say that you are a bass-head and that a 12" is good enough for most people. However, since the poster has said that he already blew one driver, I'm guessing you are correct. But, I hate to totally discourage a person.

[GSM]

I understand your suggestion and reasoning. Thats one of the big drawbacks of this type of communication. I knew I had a long story to tell so I tried to make it bearable and be humorous (ok, I failed). In any case, that svs driver did last me 5 years so i must have had some control (kids no touchy). I have realistic expectations and not comparing this or replacing the svs with this. I mentioned it as a reference of what I've heard before. Not sure if that makes any sense or not. I realize the budget is low. So low that the PE equipment I mentioned is probably my only choice. And I'm fine with that. I was hoping for some modeling help, a tuning point, port size, expected output, etc...

I hear what you're saying about the quickrete stuff - although I'm still stuck with the 16 inch limitation I'll get the real stuff. At least that way I won't have to worry about denting it while moving it around. Unfortunately I'm still stuck with the 4 foot height +/- 6" for the entire thing.

thx
Geoff

[ThomasW]

Ryan's recommendation of the Shiva-X is a significantly better solution than the other drivers discussed. Wait for PE to put amps on sale and buy the highest power one you can afford.

When you have the parts or at least have them on order, we'll run the number for your design.

BTW, factor a 4" flared port into the budget as well..$15

[GSM]

I've purchased the below:
PE 300-804 240watt plate amp for $99 (no boost)
PE 295-464 Dayton 12" reference HF subwoofer for $119
PE 091-1245 Dayton BPA-38G HD Binding Post Pair Gold $6
also got the 4inch flared port

I do realize this is a stretch for my application and most likely won't 'cut the mustard'. I'm hoping that since the wife and kids (small kids) will be using this at low to moderate volumes it will be enough. If not I can use it in my office (10x12 room, music only) and make another one for them. I like Ryans suggestion of the Shiva-X paired with an O Audio 500watt amp. My #1 objective was to get my feet wet without spending a ton of dough.

For now I'm busy playing with winisd pro and totally confusing myself in the process. Keeping the port tuned to 25 the differences between 3,4 and 5 ft^3 seem pretty small. Also for some reason I can't see any cone excursion numbers. I'm just trying to figure out what will give out first (amp/driver)

-Geoff