Questions about DIY subwoofer

Re: Questions about DIY subwoofer

Not even close.

1. Figure out a budget. DIY subs are a great value but you can go nuts also. An 18" driver from Resonant Engineering will set you back well over $1,000. Not to mention another grand on an amp to push that monster.
2. Determine how much real estate you can give up. Can you only go small? Build an end table? Go vertical? Basically design the largest box/cylinder you can live with. Or get brave and go infinite baffle. But that requires cutting a hole in the ceiling, wall or floor.
3. What do you want the sub for? Music, movies, both? How loud do you want it? Low low do you want the bass? You have to be realistic based on 1 & 2. A $100 budget and 1 cubic foot of enclosure will not get you 120db at 20hz.
4. Model model some subs in WinISD and Unibox to simulate how they will sound in your enclosure. That means the subs you look at must have published Theile/Small parameters. If they don't I would skip it and go to the next driver. Don't know how to do this? We can help.
5. Based on 1 & 4, pick out an amp to power the sub. You will also need building material like MDF or maybe sonotube. If you go ported, flared ports are nice but cost more than regular PVC. If you want to go ported but have a small box, then passive radiators are an option. Even more expensive.
6. Build it. You need the proper tools. A table saw is nice but a circular saw with a guide will work. You could also substitute a jig saw for a router but a router is the most useful tool I have for building speakers. Glue, a biscuit cutter and clamps are nice but you can glue and screw the pieces together. Remember to pre-drill the holes. Now you need a drill. Also on the building part, I recommend that you watch New Yankee Workshop on PBS. Norm may build a chair but the techniques that he uses will help you in building a box.
7. EQ it. Budget $150 for an SPL meter and a parametric EQ. You put all of this hard work into a DIY sub, why not get the most out of it?

-Robert

Re: Questions about DIY subwoofer

I agree its not all that simple. You have to not only build a enclosure for that woofer but you need to know how much air space it will require. Will you use a passive crossover or an active crossover. IMHO its alot easier to build a decent pair of DIY full range speakers than it is a really good DIY subwoofer. It takes mathematical equations and some exsperience to build a kick ass subwoofer. You could take the same size enclosure and place different woofers that are the same size and it would not sound the same. Woofers do not all create the same type of sound just like different tweeters tend to have different caracteristics as well. Its not that you can not acomplish the project but you may end up being very disapointed in the finished product.

Re: Questions about DIY subwoofer

I gave you the correct way to do this. And if you knew "about the box n stuff" you would know that the enclosure in the Titanic kit is a little on the small side.

Actually, the amp they sell with the kit has EQ built into it especially designed for that system. It is different from the regular version of the amp that you buy. It's also an easy change to "mod" the regular version of the amp, requires no tools and takes less than 30 seconds. But you don't seem to like my help. And my offer for a keyboard with a working shift key is off the table as well.

-Robert

Re: Questions about DIY subwoofer

Ticks, I don't know how much you want to avoid making a box, but I'm kind of in the same boat as you (don't know much and trying to learn) so I got a kit from rythmik audio that comes with DIY plans and they ship only the driver and amp. First this saves you on shipping by not shipping a huge box and it also allows you to get into the sub process without being able to screw it up too much (well, I'll save that for when I'm sitting here listening to my new DIY sub I guess). I guess I'm wondering what the advantage is of buying a ready-made kit from Parts Express would be? Is it a better sub than you could get for that money otherwise? Because if you're also buying the box then you basically have a lego subwoofer.

Wait, didn't you buy that jbl sub 12? That didn't work for you?

Re: Questions about DIY subwoofer

I'm cool mayn, but thanks; I have two sub projects on my plate already. If indeed you find that the box you have is a little small (you should be able to get the Thiele/Small parameters for your titanic 10 and run them in WinISD to figure this out) I've read that you can "fool" a driver into "thinking" that the box is bigger by adding more polyfill. How much? No idea, I guess you can experiment. Cause, as Robert might say, you can spend $4000 on a driver and amp but if you put it into a ill-suited box you're going to have a crappy subwoofer regardless. And that would be sad. But post how it goes.

Re: Questions about DIY subwoofer

Subs aren't "fast" or "slow". Myth #3. And Adire Audio's white paper on woofer speed goes into the physics behind it as well as how voice coil inductance affects this.

-Robert