Sub Woofer Design

[Spelled~Wrong]

I am looking for some details/scetches/anything dealing with making/installing my own sub for home theater. I would like a mid-high end sub, and I just want the experience to do it myself. I would like the design, and materials needed. I want something that really kicks, as I am moving into a new house and I have all kinds of options available. Thanx

[racer x]

are you planning on building this into the home or freestanding box . what is your idea of really kicks ??

[tpao]

I would love to give you a detailed design for a kick ass sub, but I have recently moved and all my technical reference material for speaker design is in storage. Maybe I can make some suggestions to point you in the right direction.
For speakers I would use swan305's which were available from a place called madisound. They are a 12" sub with a low resonant frequency (Fs), and will preform well in a sealed enclosure. They are also cheap, I paid $50 each for mine, I'm sure they cost more now.
I would put them in a band pass enclosure, which is a ported enclosure where you have three seperate chambers. Two sealed chambers with the speakers fireing into a commen ported chamber. Build your sub so the port is aiming into the corner of your room. This is called corner loading, it will give you a great sound. There are often good articles in "Speaker Builder" magazine.
Pay attention to you crossover design, this will be very important. There are companies that will do a computer crossover design for you if you give them the specifics of your design. This is the easiest way out if you don't have a function generator, multimeter and crossover design software.
I wish I was able to give you more info, design formulas, etc. If you have any questions feel free to PM me, I'll try to help.

[Spelled~Wrong]

I am looking for a sub that will give good bass sound for movies as well as something thunderous for music...I don't listen to alot of rap..mostly metal, classic rock, and some rap (mostly Dj jazzy jeff & fresh prince, etc)...I am pretty good with woodwork so that won't be a problem...I would like to have something that I could run off of an older reciever so I would be building two of the same thing (my reciever requires both channels to work for it to put a signal out and I can't bridge it) one for the left channel and one for the right. If anyone could point me anywhere (website, stores, etc) I would greatly appreciate it.

[tpao]

You make your receiver work in stereo you have a few options.
1. Build a pair of subs, a right and a left.

2. Build one sub with two speakers and wire one right and one left. There is not really any right and left separation in the lower frequencies where your bass is, so this will work fine.

3. Use a dual voice coil woofer, a speaker with two sets of inputs. 2+ and 2- use one for right and one for left.

If you are using an older receiver with a built in amp, you may be asking for problems, unless it is a very powerful high quality receiver. Subs are power hungry and you will want to feed them more than 50 watts per channel. It is not too much power that blows speakers, it is lack of power that blows speakers. If you want 12" or 15" subs you better get a good 200+ watt amp to use them to their full capacity. You said you wanted something that really kicks. You won't get it with your Sony receiver you got from sears.
The system I was describing above I built out of 21" PVC pipe, they stand over 5 feet tall, and consumed more than one full sheet of high density particle board each. It takes three to 4 people to move these suckers. They use a total of 4 12" woofers with 400 watts of power, they are ported and tuned to 19Hz. When they are turned up they shake the walls. Now these kick. They are also a great conversation piece when friends come over, most can't believe I built them myself.
I'm not trying to discourage you, speaker building is a great hobby, and much more than just building a wooden box. I've done several pairs that sound incredible, but it takes a lot of time, reasearch and understanding to pick a project that is right for you. It is truely rewarding to hear your finished result when you are done. Good luck.

Try these sites to get started, you may find some ideas here.

http://www.hi-fi.com/speaker/

http://www.speakerbuilding.com/

http://www.audioxpress.com/magsdirx/spkrbldr/

Or do a web search for "speaker builder" there are 100's of sites.

[spyguy]

AIR SPACE! Not too much, not too little. Base is nondirectional and you will find that the more "surfaces" the sound is toward (bounced off of), the higher the db and the more uniform the resonance. To "squeeze" response from a base speaker, the design of the box/enclosure is key; however, not to be overlooked, is WHERE the speaker/box is placed. In short, have you ever noticed the best "concert halls" don't have a WALL of speakers rather, their speakers are concealed and WELL placed? SG

[Spelled~Wrong]

Thanx guys....I will be running these/this sub off of my older JVC reciever that pushes to 15" (3 way) speakers, and it delivers 150W per channel.