# Home Subwoofer **URL:** \ **Category:** Factual Questions\ **Created:** [September 26, 2002, 11:10pm UTC](https://boards.straightdope.com/t/home-subwoofer/129784 "2002-09-26T23:10:10Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![RaginAzn](https://avatars.discourse-cdn.com/v4/letter/r/9fc348/32.png) [@RaginAzn](https://boards.straightdope.com/u/RaginAzn)\ **Post date:** [September 26, 2002, 11:10pm UTC](https://boards.straightdope.com/t/home-subwoofer/129784/1 "2002-09-26T23:10:10Z")
I was scrounging around in my basement when I pulled out a crusty old 12" woofer. It was probably my brother’s at some point, and he said I could have it. There’s this thing in my room that looks like a 2’ cube made out of sheets of particle board, and then veneered. the walls are only about 1/2" thick, but I figured that since it’s an old woofer, it won’t be sounding good at all anyway. I cut a hole in the bottom, and plopped the woofer in. So basically, what I have is a big particle board cube with a big woofer in it, with no crossover and no intentions of spending money on a crossover. The cube has little rubber legs, so those will allow airflow out the bottom. In the back of my mini system is a little RCA jack that says “Super woofer”. Where would this go? I’d imagine it goes to an amplifier, or an amplified woofer that Aiwa (the brand of my system) sells. I was wondering, though, are there any for-the-home subwoofer amplifiers out there? How much would they cost, and would I need a crossover anyway, even though it’s a _subwoofer_ amplifier? ---
**Author:** ![Rhum\_Runner](https://avatars.discourse-cdn.com/v4/letter/r/2bfe46/32.png) [@Rhum\_Runner](https://boards.straightdope.com/u/Rhum_Runner)\ **Post date:** [September 26, 2002, 11:17pm UTC](https://boards.straightdope.com/t/home-subwoofer/129784/2 "2002-09-26T23:17:06Z")
Many “subwoofer” amps have built in x-overs. Try [www.partsexpress.com](http://www.partsexpress.com) - FYI, note that there is a “sex” in that URL also [www.madisound.com](http://www.madisound.com) You probably need a new driver, both these sites sell drivers too. What do you mean by “airflow” out of the bottom? Is the cube ported? or does it not have a bottom? ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [September 26, 2002, 11:18pm UTC](https://boards.straightdope.com/t/home-subwoofer/129784/3 "2002-09-26T23:18:28Z")
You would only need a crossover if you were driving more than one speaker type, woofer + tweeter, with the same signal. You’d need an active passover if you do it before the amp but simple passive passovers work after the amp. you shouldn’t need a special amp. Just make sure impedance is reasonably matched so you don’t burn up anything. ---
**Author:** ![RaginAzn](https://avatars.discourse-cdn.com/v4/letter/r/9fc348/32.png) [@RaginAzn](https://boards.straightdope.com/u/RaginAzn)\ **Post date:** [September 26, 2002, 11:25pm UTC](https://boards.straightdope.com/t/home-subwoofer/129784/4 "2002-09-26T23:25:54Z")
Yeah, I’m definitely not going for the all-out audiophile setup at all. I just figured it’d be a nice project to occupy myself with. I was hoping they’d have some cheap/old $50 amplifiers around, but I’m definitely not spending $100 on an amp without a decent driver and cabinet (which would defeat the purpose of being cool by having a not-good-at-all-but-usable subwoofer made entirely of sketchy basement parts) Btw, the cube is basically a cube with little feet that raise it about half an inch off the floor. The driver points down, and would be muffled if it weren’t for that space. ---
**Author:** ![Rhum\_Runner](https://avatars.discourse-cdn.com/v4/letter/r/2bfe46/32.png) [@Rhum\_Runner](https://boards.straightdope.com/u/Rhum_Runner)\ **Post date:** [September 26, 2002, 11:33pm UTC](https://boards.straightdope.com/t/home-subwoofer/129784/5 "2002-09-26T23:33:27Z")
I have no idea what the output from a mini system is, but if it is a full range signal, (and I suspect it is) **RaginAzn** will most certainly need a crossover of some kind. You do **not** want to feed a full 20-20khz signal to a 12" woofer. ---
**Author:** ![EasyPhil](https://avatars.discourse-cdn.com/v4/letter/e/e47c2d/32.png) [@EasyPhil](https://boards.straightdope.com/u/EasyPhil)\ **Post date:** [September 27, 2002, 3:59am UTC](https://boards.straightdope.com/t/home-subwoofer/129784/6 "2002-09-27T03:59:15Z")
That cube needs to be ported, i.e. it needs a hole in it for air top escape. Do a search on the web for porting, so that you can get better low end from the setup you’ve created. ---
**Author:** ![Rhum\_Runner](https://avatars.discourse-cdn.com/v4/letter/r/2bfe46/32.png) [@Rhum\_Runner](https://boards.straightdope.com/u/Rhum_Runner)\ **Post date:** [September 27, 2002, 4:12am UTC](https://boards.straightdope.com/t/home-subwoofer/129784/7 "2002-09-27T04:12:04Z")
> [@](#): > > \*Originally posted by EasyPhil \* > \*\*That cube needs to be ported, i.e. it needs a hole in it for air top escape. Do a search on the web for porting, so that you can get better low end from the setup you’ve created. \*\* The enclosure most certainly does not have to be ported. ---
**Author:** ![Rhum\_Runner](https://avatars.discourse-cdn.com/v4/letter/r/2bfe46/32.png) [@Rhum\_Runner](https://boards.straightdope.com/u/Rhum_Runner)\ **Post date:** [September 27, 2002, 4:14am UTC](https://boards.straightdope.com/t/home-subwoofer/129784/8 "2002-09-27T04:14:52Z")
I can’t believe I have used the phrase “most certainly” twice in one thread. Please feel free to release the hounds. ---
**Author:** ![emolson](https://avatars.discourse-cdn.com/v4/letter/e/5fc32e/32.png) [@emolson](https://boards.straightdope.com/u/emolson)\ **Post date:** [September 27, 2002, 5:32am UTC](https://boards.straightdope.com/t/home-subwoofer/129784/9 "2002-09-27T05:32:03Z")
> [@](#): > > \*Originally posted by Rhum Runner \* > \*\* > The enclosure most certainly does not have to be ported. \*\* …if it is an “acoustic suspension” enclosure. A “bass-reflex” enclosure has a tuned port. Different designs, different specs, different responses. Radio Shack has a couple of books on speaker design: #920-0041 and #920-0002. I’m not familiar with these, but I have an older book that is quite helpful. ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [September 27, 2002, 12:29pm UTC](https://boards.straightdope.com/t/home-subwoofer/129784/10 "2002-09-27T12:29:07Z")
I have those same books (somewhere…). I’m sure if the vital statistics of the speaker are posted, someone can try to find them and use the equations to come up with some “ideal” cabinet/port sizes. ---
**Author:** ![EasyPhil](https://avatars.discourse-cdn.com/v4/letter/e/e47c2d/32.png) [@EasyPhil](https://boards.straightdope.com/u/EasyPhil)\ **Post date:** [September 27, 2002, 6:42pm UTC](https://boards.straightdope.com/t/home-subwoofer/129784/11 "2002-09-27T18:42:43Z")
> [@](#): > > \*Originally posted by Rhum Runner \* > \*\* > The enclosure most certainly does not have to be ported. \*\* My bad, I shouln’t have said “has to”. Most sub-woofers I’ve seen are ported and most bass cabinets I’ve seen and used are ported. ---
**Author:** ![emolson](https://avatars.discourse-cdn.com/v4/letter/e/5fc32e/32.png) [@emolson](https://boards.straightdope.com/u/emolson)\ **Post date:** [September 29, 2002, 6:23am UTC](https://boards.straightdope.com/t/home-subwoofer/129784/12 "2002-09-29T06:23:07Z")
{slight hijack} I built a subwoofer from plans I found in a 1980 or so _Digital Audio_(?) magazine. It is acoustic suspension and uses a 12" dual-coil driver. It really sounds great, and now I wish I had the driver and plans for a 15" one. {/slight hijack}