Building a Subwoofer

[Xyberz]

Okay, I'm looking to build a budget subwoofer with a few requirements. Help would be greatly appreciated. I want to build a subwoofer box that is as small as possible but have pretty decent sound. I'm not sure what the best type of design is. Even though I've read a lot of negative about the Bose Acoustimess, I like the design of the box and was wondering if I could incorporate it with maybe just a single 10 inch. I live in an apartment so I don't need something to shake the whole building. I'm not sure what type of speaker, but it has to be really really afforadable. I'm just a poor boy who is looking for theatre quality and bargin basement prices. Any links, pictures, designs would help out a lot. Please no tech talk, I'm just a lamer and just need step by step instructions.

Requirements:
Smallest box design possible
$50 budget for woofer
Any subwoofer or combination of woofers
Efficient sub to operate on 175W peak power

Also does anyone know where I could get some really good Bose cube style speakers? I just don't like the looks of having speaker stands all over or old fashioned big boxes all over the place. I don't mind sacrificing a little for compact. Definately not expensive stuff either. I'm currently looking at a brand called Vidsonix and they're 30W RMS each and come in a set of 3 or 2 cubes for about $20-30 a set. Here are the specs for each cube:

- 3" High Output Full Range Driver with A/V shielding and high temp voice coil.
- Excellent stereo imaging and sound matched performance.
- Internal padding and damping material eliminate cabinet standing waves, allowing for cleaner sound response.
- Includes custom wall mounting brackets.
- 30 Watts (r.m.s.)/ 60 Watts Peak Music Power each
- Impedance: 8 ohms
- Freq. Response: 150 Hz to 20K
- Size: 3.8" x 4.1" x 4.3"
- True Black finish made of high-impact, textured plastic.
- Includes rubber feet for non-skid and non-scratching durability.

So I just need 5 total for a 5.1 Surround sound system. Also just picked up a Sony Dolby Digital 5.1 Surround reciever w/remote in new condition for $100. As you can tell, the best quality possible for the lowest price. My total system hopefully will be about $225. I know it's one of the hardest things to do when it comes to home theater systems, but we all have to start somewhere.

 

[FrankDIY]

Sealed box are usually the smallest. For subwoofers, I always suggest to not go below 100W RMS.

 

[Pete Mazz]

Shop around for the Home Theater in a Box (HTIB) setups. You'd probably spend more doing it yourself.

Pete

 

[Xyberz]

True, but my system would probably just tear away those theater in a box setups. The reciever I just bought has 100Wx2 Stereo and 80Wx5 THD Surround Sound. Much more than box systems. The ratings would be good for the cube speakers I'll be picking up, which rate at 30W RMS. All I need left is to either get a powered subwoofer or make one at least 100W RMS. Not bad for a true 5.1 Surround sound system.

 

[cowanrg]

i agree with pete. a DIY would end up costing you more, and frankly, those home theatre in a box's would tear your DIY project in two... yours might beat up on the bose setup, but most of the others would hand you a 6-pack of woop-***.

i work at a audio/video store, and we have around 8 of those setups, and i was even impressed, and usually im in the high-end room listening to the krell/martin logan setup. but the home theatre in a box have come a LONG way. for a few hundred, you can get soem amazing performance.

and dont be fooled by bose, just because they arent shown with stands doesnt mean you can just put them wherever. remember, tiny cubes and big towers ALL need wires run to them... so you can surely have your bose cubes in the top corner of the room, but you gotta still run a wire to them. even decent sized bookshelves can be mounted to the wall relatively easy now...

i would suggest getting a budget together first, and then going from there. if you have $300 to spend, go with the home theatre in a box... if you can only spend $100, maybe built it yourself. but trust me on this one, spend every dime you can on the project, in the end you wont be sorry.

 

[planet10]

small, small DIY 5.1 HT

I was discussing a small woofer with a friend the other day. The ApexJr 8" sub fits in a tiny box (they have a sealed box w 0.57 Qt at under 0.4 cu ft -- i'd go for 0.5 Qt and try to take better advantage of oom gain). The 3" Tagbands with the phase plug (2 with just different baskets). A fellow on the FR Forum built 4" cubes out of aluminum plate for these, and Logitech uses them in very small satelittes for their very well reviewed computer speakers.

5 Tagbands, 1 woofer, gets you up to $90 + ship for drivers. Then you need a small plate amp, you have the budget receiver, away you go.

dave

 

[Xyberz]

2 Goldwood GW-206/8 6-1/2" as a Sub?

I was just checking out some small woofers to make a small subwoofer enclosure. These woofers are pretty cheap from Partsexpress.com and and good ratings. Only $11.70 each. Two subs would be a total of 180W RMS and 360W peak. That's a pretty decent rating and is much better than the bose acoustimass. The speaker specs are below:

Specifications:* Power handling: 90 watts RMS/180 watts max * Voice coil diameter: 1-1/2" * Frequency response: 60-3,000 Hz * Magnet weight: 20 oz. * Fs: 62.5 Hz * SPL: 86 dB 1W/1m * Vas: .40 cu. ft. * Qms: 3.13 * Qes: 1.35 * Qts: .95 * Xmax: 3.5 mm * Net weight: 3 lbs. * Dimensions: A: 6-1/2", B: 5-5/8", C: 3-5/16", D: 4", E: 1-1/4".

What's the best way to make a box for 2 of these speakers in the smallest box possible and best type of box? I like the style and size of the Acoustimass and would think that these speakers would work pretty good in that design. But is there a better one where I could get better frequency response? I would like the frequency to be toned down to pretty low, as I see the ratings they individually respond between 60-3000hz but I'm pretty sure there's a box and setup that could tune it down some more. I hope that there is already a good setup like this or links with instructions to some website. I understand that you need a good box, pretty good speakers, ports, and a crossover. Info about a complete system would be greatly appreciated. Basically this is a ground up project and just from reading some of the articles listed, I can tell that there are a ton of people that have massive amounts of knowledge on this subject. Hopefully there is someone out there that can help me out in my situation.

I'm a newbie to building and box and have no technical knowledge of specs or anything of that sort. I'm looking for cheap for now as I really don't have much money and just want to make the best of what I have. I can appreciate that until I have much more money for a really grand design, then I can ask about that.

 

[JohnR]

Because of the high Qts this driver will have a fair sized peak in the 100 Hz region. A better cheap driver might be the "ULTIMATE WR1025CS" driver they have for 18.50, it looks ok in a sealed 1 cu ft box. But you still have to pay shipping. I think the apexjr sub dave mentioned would be a better choice, or the 8" Tangband.

Since you'll be driving the sub from the .1 output on your receiver you don't really need a plate amp, if you can find an old amp cheap somewhere.

HTH!

JohnR

 

[planet10]

Since you'll be driving the sub from the .1 output on your receiver you don't really need a plate amp, if you can find an old amp cheap somewhere.

Good point. If you can find an old integrated amp or receiver at a thrift store or garage sale you could use that. Would work best if you could get at just the power-amp section, which on most budget amps would require some surgery (Not: this is not necessary just desirable). A plate amp in the sub might be better space management and some surplus plate amps (ie like some at ApexJr) can be cost competitive with the thrift store special.

dave

 

[Xyberz]

Because of the high Qts this driver will have a fair sized peak in the 100 Hz region. A better cheap driver might be the "ULTIMATE WR1025CS" driver they have for 18.50, it looks ok in a sealed 1 cu ft box. But you still have to pay shipping. I think the apexjr sub dave mentioned would be a better choice, or the 8" Tangband.

Since you'll be driving the sub from the .1 output on your receiver you don't really need a plate amp, if you can find an old amp cheap somewhere.

HTH!

JohnR

Awsome! I think I'll purchase the Ultimate subs now! Thanks for the info. I'll be purchasing 2 subs for that price now. 160W RMS and 360W peak is good enough for me. 10's should move much more air than 2 6-1/2"woofers. Now to decide on the perfect small enclosure.
Can anyone help me on any type of really small enclosure and tuned down to the 36 Hz it's rated at? Or mavbe even lower! I need the exact info and building measurements and if it's ported, best type of ports and what size, box filler, type of crossover etc. I'm still trying to keep the price pretty low. The subs will be $37 for 2 not including shipping. A quote on a good port(s) and crossover would also be excellent. I guess for parts, still trying to keep the cost around $50 not including shipping prices.
Thanks to everyone for the great suggestions and help, really appreciate it a lot!

 

[Xyberz]

How bout a pair of Peerless 8" model 850136? I might be able to pick these up at even a better price than the Ultimates? Specs below:

* Power handling: 150 watts RMS/210 watts max * Voice coil diameter: 1-1/4" * Voice coil inductance: 2.6 mH * Nominal Impedance: 8 ohms * DC resistance: 5.9 ohms * Frequency response: 29-4,000 Hz * Fs: 28.2 Hz * SPL: 89.5 dB 2.83V/1m * Vas: 2.82 cu. ft. * Qms: 3.5 * Qes: .29 * Qts: .27 * Xmax: 4mm * Net weight: 3.8 lbs. * Dimensions: A: 8-1/2", B: 7-3/4", C: 3-3/4", D: 4"

Also the 10" Peerless CSX model.

* Power handling: 200 watts RMS/280 watts max * Voice coil diameter: 1-1/2" * Voice coil inductance: 2.9 mH * Nominal Impedance: 8 ohms * DC resistance: 5.5 ohms * Frequency response: 23-1,800 Hz * Fs: 22.6 Hz * SPL: 88.2 dB 2.83V/1m * Vas: 5.10 cu. ft. * Qms: 2.56 * Qes: .40 * Qts: .35 * Xmax: 9mm * Net weight: 6.8 lbs. * Dimensions: A: 10-1/16", B: 8-1/2", C: 4-1/4", D: 4-1/2".

I understand that Peerless is a really good brand. Maybe better than the 10" Ultimates? Not sure, I'm still new and would like to get some feedback regarding these three models. Also I would like to stay within the small box region without any real loss of quality or sound.

 

[schizeckinosy]

really small box

If box size is of overriding concern, then you might want to look at an isobarik setup. Really small box with no loss of quality. Double the drivers and half the efficiency, though . Basically it is two drivers sandwiched into one, installed in one hole.

Look at some car audio designs for this one.

Cheers, Dan

 

[Xyberz]

I've found some info on Passive Radiator subs, just like the awsome Sunfire sub. I think I'll save up some more dough and make a small compact enclosure like the Sunfire. Would the below setup be pretty good?

Peerless 10" XLS Sub (About $120)
(2) 10" Passive radiators fromHuman Speakers (Only $32 each!)
250W Subwoofer Amp from Partsexpress.com ($120)

I'm not sure what type of crossover to use, of maybe just the one that's built in the amp. So total comes to about $305. Not bad for a passive radiator sub.
The sub will be built pretty much the same as
Adrian's Thunder Box
Hopefully the enclosure can remain to about 1 - 1.5 cubic foot and hit about 20Hz or so. Is this a possiblity without spending anymore money? BTW, wood will be free from my wonderful friends over at our local hardware shop.

 

[navin]

at $50 for a driver it is time to search the discount bins for a 8 or 10"

in general look at Peerless (it is now a Vifa company along with SS), Dayton, or maybe even a car woofer.

i have seen quite a few 8" and 10" drivers (single) but forget where as I write this.

regards
navin "to box or not to box - THAT is the question"