Building a Sub woofer doable? [Archive] - Audio & Video Forums

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CharlieBee
12-09-2004, 09:02 PM
While cruising walmart.com for some mini dvd discs for camcorder I saw an ad for a Pioneer 12" 600 watt peak subwoofer for $58. They had maybe 20 speakers, and several other subs.

They recommended an enclosure of 1.5 cubic feet. Sub has 91dB sensitivity (is higher better?). 4 ohm and 20 Hz to 4000 Hz and two coils so each channel of my receiver can be hooked up. Is an separate amp needed? Is a Crossover needed?

I just want to improve my bass (only have 10" woofers) and the wife will not let me turn my Sansui 9090dp above a few watts. (it is rated at 125w/ch at 8 ohms rms and is a real powerhouse not like some of these newer, wimpy receivers, this thing is 53 lb with a hugh power transformer)

Has anyone made a cabinet for one of these subs? Would just a sub and cabinet work?
Is a duct needed? Any plan source?

Charlie

kexodusc
12-10-2004, 05:49 AM
Building a sub can actually be very, very easy. I would however suggest you look at tested and proven kit designs from several places. Parts Express has a bunch of ideas for their Dayton drivers...for around the same money you're looking at, you can get a far, far, superior unit, and a tested and proven design. The cabinets can be purchased too. Look on the right hand side menu for subwoofer kits and cabinets etc...then check out the Dayton Audio drivers for some decent 12" options. If you don't plan on using this too much for home theater and are looking for more music "oomph", I'd recommend the Dayton Quatro line...
The parts express "tech talk" board is full of people that will be happy to help you out too. I don't think anyone would argue that you'd be way better off to ignore the Pioneer woofer.

I'm actually leaning towards building the 1000 watt, 15" Titanic MKIII for myself next month, great for music and HT, which is what I need in my system now that I'm getting into multi-channel audio. I built the 12" equivalent for my parents last year originally it was going to be for me, but I liked it so much, the possibility of a good, affordable 15" was too hard to resist....That 12" easily topped my $900 Paradigm subwoofer for less than half the price.

Good luck.

Woochifer
12-10-2004, 02:54 PM
While cruising walmart.com for some mini dvd discs for camcorder I saw an ad for a Pioneer 12" 600 watt peak subwoofer for $58. They had maybe 20 speakers, and several other subs.

They recommended an enclosure of 1.5 cubic feet. Sub has 91dB sensitivity (is higher better?). 4 ohm and 20 Hz to 4000 Hz and two coils so each channel of my receiver can be hooked up. Is an separate amp needed? Is a Crossover needed?

I just want to improve my bass (only have 10" woofers) and the wife will not let me turn my Sansui 9090dp above a few watts. (it is rated at 125w/ch at 8 ohms rms and is a real powerhouse not like some of these newer, wimpy receivers, this thing is 53 lb with a hugh power transformer)

Has anyone made a cabinet for one of these subs? Would just a sub and cabinet work?
Is a duct needed? Any plan source?

Charlie

There are so many approaches and vendors for doing DIY subs, the choices are pretty staggering. Answers to your questions depend on the kind of setup you're looking for.

You can build a passive sub, which would still need a crossover unless you plan to just run the sub in parallel with the main speakers (something you probably don't want to do because all it really does is function like a bass boost switch).

Most subs nowadays are active subs with their own amp. This is because the low frequency peaks with home theater sources can put a big load on an amp. Most of them include the crossover.

If you decide to build a sub, the first question is what kind of cabinet you plan to use. Most of the time, the choice comes down to ported versus sealed. Ported subs are more efficient and can go louder, but they're also a lot more difficult to design properly. With ported subs, you have to precisely match the interior volume with the size of the port opening for specific performance parameters.

Sealed subs are easier to design and build because the port opening is no longer a variable you need to account for. Sealed designs are more forgiving if your measurements and woodworking skills are less than precise. Even though its less efficient and the dropoff in bass output begins sooner, a lot of people prefer the sound of sealed subs because it might subjectively sound tighter or more "musical" (whatever that means).

Adire Audio sells drivers and amps, and posts plans for different subwoofer configurations specific to the characteristics of those drivers. The links below are the sealed and ported application guides to Adire's 12" Shiva driver. You can either build your own cabinet with those plans. Or you can buy from another vendor like Acoustic Visions, which sells both prefinished cabinets and flat-packed precut kits that you assemble yourself.

http://www.adireaudio.com/Files/SealedShivaApplications.PDF
http://www.adireaudio.com/Files/VentedShivaApplications.PDF
http://www.acoustic-visions.com/~acoustic/products/subwoofers/enclosures/pricing.shtml

poneal
12-13-2004, 05:05 PM
since it frequency goes up that high. Subs normally operate from 20-500hz at most. An excellent DIY driver choice would be the dayton 12" quattro. It has plans on the site for the box. This would be your best value for the money. Here is a link to the quattro and a plate amp.

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=295-555
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=300-804
This will get you what you need.

fudgemik
12-15-2004, 11:06 PM
charlie bee first of all those 2 coils that u think u can hook up to each speaker terminal on your amp , i hope your joking!!!!!! all that means is it has a dual voice coil (DVC) and that gives the speaker more load configuring capabilities not more speaker terminals to plug it into, u should do a little research on dvc woofers......and yes if u took that pioneer subwoofer u could make it kick ass in your home.....no need for ports just a sealed enclosure, i say that cause almost all pioneer subs if not all of them are sealed enclosure(most low end speakers are , but atleast the box design is more forgiving to errors) and i dont care if they say 1.5 u better make it between 1.75 and 2 and dont forget displacement of the speaker......also there is no crossover on that speaker so i hope what ever u feed it is low passed at 100hz 12db slope, no information over 100hz............good luck..........p.s. to go thru all of the whole box building thing do yourself a favor and get a decent pioneer sub, not top of the line but not bottom of the line, like say the IMPP model, i like 12" subs............

royphil345
12-16-2004, 02:07 PM
Ya' know those cheap passive sub / sat combos they sell all over the place? How do you think they work? Dual voice coil subs can solve many car stereo installation and impedance problems, but they were originally developed to solve the problem of using a single passive sub for stereo. How would you suggest he make that Pioneer subwoofer "kick ass" in his home? Hook it up to one channel and hope the bass comes from over there? Radio Shack used to sell a separate passive sub that used a dual voice coil driver along with some higher-end companies before powered subs became the norm.

Anyhow... I'm guessing that this Pioneer is a car sub with two 4ohm voice coils. So, if you hook up a channel of your amp to each voice coil, then connect your main speakers in parallel you're going to have about a 3ohm load at best (assuming you have 8ohm main speakers) That will probably kill a home stereo amp pretty quick. Might work if you have A and B speaker outputs and your manual says it's ok to plug 4ohm speakers into one of them. (A dual voice coil sub designed for home use with two 8ohm voice coils would be better) Still, it probably wouldn't sound too good without a crossover for each channel that matched where your main speakers begin to drop off and a stereo L-pad volume control to match the loudness of the sub to your main speakers. To do this right wouldn't be an easy job. (would need to be a pretty good speaker designer) Actually, with the store-bought passive subs you would hook the amplifier straight to the the sub. The sub had outputs to your speakers. Sub had a passive crossover that crossed the sub and speakers over at a fixed frequency. Crossover network in combination with choosing a driver of the right impedance and efficiency also ensured a proper impedance load on the amp and a proper volume level between the sub and speakers. Sorta' tricky for a beginner...

Which is one of the reasons powered subs have become so popular. Makes it very easy to match the sub to your speakers. Don't have to worry about as many factors when selecting a driver. Much better performance too. I agree with everyone who said you should take a look at building a powered sub. Since your system is only two channels, and your wife won't let you turn it up anyway, you shouldn't need a very big amplifier. You can find alot of powered sub amps on the web at pretty reasonable prices with built-in adjustable crossovers + all the connectors already installed. Just add a box and a driver. Since it doesn't sound like you're after the ultimate in performance, have you checked out some of the cheaper ready-made powered subs? Think some of them would sound better (especially if you don't need loud) than a first attempt at a passive sub.




A few words from some people who manufacture subwoofers for a living...


The primary advantage of the dual voice coil speaker is wiring flexibility. A single dual voice coil driver offers the user three hookup choices...parallel, series and independent. In a parallel hook-up the drivers impedance will be half that of each individual coil (a dual 4 ohm speaker would be a 2 ohm speaker in parallel.) A series hook-up results in twice the impedance of each single coil (a dual 4 ohm speaker results in 8 ohms if its coils are wired in series.) Finally, you can wire each voice coil to a separate channel of your amplifier, which can be useful if your amplifier is not mono-bridgeable or if you are bridging a four channel amplifier down to two channels to run your sub.

The independent wiring application is the one that brought about the need for dual voice coil speakers in home audio. Unlike most good car amplifiers, home amplifiers and receivers are typically not mono-bridgeable. For this reason, dual voice coil woofers were developed so that a subwoofer or center speaker could be driven from the left and right channels of the average stereo home amp/receiver. Since sub-bass frequencies are hard to localize, the dual voice coil subwoofer allowed sub-bass reinforcement within one cabinet and one speaker. This cabinet could be placed inconspicuously in a corner or along a wall of the listening room, with the obvious benefits being space-efficiency and lower cost than two independent bass cabinets or a larger cabinet with two subs in it. Many popular home subwoofer / satellite speaker systems still use this basic configuration.

fudgemik
12-16-2004, 09:40 PM
royphill i should have been a little more clear on my post. U ask how can that dvc pioneer 12" sub kick ass in his home ?? Well i am assuming he has dolby digital receiver at least, then the subwoofer pre out from the receiver goes to an active crossover , then to an independent amp, then to his pioneer sub.......... if no crossover then a passive coil after the amp before the sub...............u were talking in regards to him using a stereo receiver (2 channel) and connecting it in the terminals with other speakers, of course that wont workout properly........, i was referring to 5.1 or higher receiver using the sub pre out.......not the main terminals on the receiver..............hope this helps him understand

Ryanm
12-17-2004, 07:27 AM
I could be wrong about this but I've heard a *lot* of sub boxes at my local car audio place and quite honestly they never sound as good in the store as they do in a vehicle. Reason being they're not designed for use in a home. There's a reason audio manufacturers that sell both car and home audio have different pages on their website for each. Same goes for putting house speakers in a car, it can be done sure, but they never sound as good as speakers actually meant for a car, as well as impedance issues etc.
I would go with the advice given and go with a system from parts express or another company to build your own home subwoofer with proven design

fudgemik
12-17-2004, 08:20 AM
i understand your point completely but were not talking about a pre fab box with a sub from a manufacturer, were talking taking a car sub and desingning your own box for your home, i dont know how many of you guys have ever experimented with building enclosures with car subs for use in the home but i have a good fifty or so under my belt, i have had many dif. types of box designs as well as many dif. brand speakers, my home subwoofer right now im using i built and it has 2 earthquake 12" in a ported enclosure, it has some serious output. ive heard all the home stuff too, i have a local store by my home and sat in their lstening room which consisted of all meridian and 2 15" velodyne home subs, probably 150,000 dollar setup, yes they had bass but nothing compared to my home subwoofer or previous ones for that matter.....Dont get me wrong, the top home stuff is damn good and very smooth but pull one of those subs out of the box and u will see a dinky speaker, now a car sub is gonna have 4" voice coils , some have double spiders (like my earthquakes) power handling galore, incredible excursion capability, just plain big time output............i know alot of u are gonna disagree with me but i have experience first hand for oh lets say 15 years now.......(yes ive had some killer car systems when i was younger too) when it comes to home theatre could a top velodyne outperform my setup, POSSIBLE, YES IT IS POSSIBLE! But i also listen to regular music, be it rap or whatever and those home subs will fall on their ass if u throw some rap music or any music with some serious bass at it........ I guess I will have to build one and give to a moderator at this site and let him post results, im all for it..................Besides for 58 bucks or whatever the price originaly was for the sub, u aint gonna get no home sub for 58 bucks.....

Easy E
12-18-2004, 05:00 PM
Ok I have to agree and disagree with the last post. Home audio subs yes most of them do have some output but they are very pricey. There are smaller companies that do make some serious home audio stuff. They also make some serious car audio equipment as well. Being familar with woofer design and being in the audio industry I can comment a few things about car and home audio designs speakers etc.

First off when designing a speaker you have 3 things you can chose from that everyone wants. One of them is being able to play low frequencies, the other is small box and the third is efficency. Now when designing a speaker you cant have all 3. You can have parts of each, but you cant have all three.

Example car audio subs are designed to use small enclosures and either be efficent or play low depending on the subwoofer. Reason being is because car audio power is cheap, so efficency doesnt matter and having alot of low end doesnt matter either because of the cabin gain helps the woofer out/

Pro Audio most subs are designed for high efficency and end up not being able to play low and dont care about box size.

Home Audio subs are designed to play low and to be efficent for the most part, so they use large enclosures which is fine because in home audio you dont have as much space constraints as you do in car audio. Also in home audio you need low end because you dont get as much cabin gain as the car audio enviroment.

Now there is plenty of home audio drivers out there that are top of the line, they have more linear throw then pretty much any other car audio driver on the market. Like the Adire Audio Tumult, it has 34mm one way xmax on a 15" driver. Remeber low bass its all about moving area, more throw you have louder it can be, this rule applies for sealed enclosures and some what applies for ported enclosures.

So yea back to the point what you were saying now you have some background info about the different subs. Sure you can get a cheap pioneer sub and build a right box for it. It should have some output most likely semi efficent for a car audio sub but it wont be able ot play the low notes that well. But hey what can you expect for a $58 sub not that much.

Ok by the way doubble spiders isnt necessarily better, one spider can usually get the trick done unless you are reaching for a reall high FS. Also having a huge motor can be a bad thing because too much BL can be bad depends on what you are trying to achieve. Its all trade offs when designing a subwoofer. Anyway I am done preaching.

fudgemik
12-26-2004, 06:55 PM
excellent post easy e!!!!!!!!!!! You are absolutely right about the gain inside the cabin of a car and all other points..............I would agree with you about the lower frequencies being better with the top home stuff but I will tell you I built a bandpass that contained 2 12" hart car audio subwoofers, which they dont make anymore and let me tell you it could go way down.....................

derekwwww
01-03-2005, 09:25 PM
Hello guys, I was planning on using two 12" Image Dynamics IDQ subs each in their own enclosure each with their own amp. I was planning on buying a couple of the 240 watt plate amps from Parts Express and using them. Can anyone recommend specs for building these enclosures? I have built car audio boxes before but I am just getting into home audio so I am new to this. I was told the box that these IDQs take in a car will be different them for a home. So maybe fudgemik you know since you say you have lots of experience using car subs in home applications. Also how much louder would ported be over sealed?

thanks

fudgemik
01-14-2005, 06:18 AM
generally i would increase the the cabinets volume for home application, like say if the sub calls for 1.75 bump it up to 2.00 and as far as ported playing louder than sealed , yes it will with less power needed! But not all wooofers are made for ported enclosures and i dont know what your sub calls for. But hey i have done things besides what manufacturer reccommends and it was fine and other times it was not.....

Easy E
01-16-2005, 09:10 AM
So your looking to use your 2 IDQs in home audio. I have a little experince using the old ID series in home audio. Are you looking for a lot of low end extension or just alot of bass up higher or what? Want a peak around 30hz or have it have a nice low end to 20hz? Looking for sealed or ported enclosures. To get the most out of the woofer I recomend ported. I use alot of home audio speakers in car audio etc.

derekwwww
01-16-2005, 07:25 PM
Yep I have the boxes built already. Each enclosure is 1.06 cuft sealed after subtracting speaker displacement and according to WinISD...:



Closed box 30 litres f3 = 45Hz - fb = 46Hz - SPL = 87dB 1w


My amp thats going to be running my subs also has a parametric EQ that includes up to 6 dB boost with a setting range of 18-80 hz and also has bandwith control on it to control how 'wide' or 'narrow' the boost is. Do you think my results will be good? Each sub getting a clean 250 watts rms each.

Easy E
01-18-2005, 12:38 PM
I dont think you will have good results because the enclosures are a bit small, and since you are using car audio sub I would recomend ported to get some real lowend extension. The sealed box is a bit small and going ported will bring in some more low end. But you can try and see how you like it first.

derekwwww
01-18-2005, 04:56 PM
Well according to WinISD my boxes should have been 22.4 litres each so I posted on the WinISD forum and got help there where they recommended 30 litres each enclosure instead of the recommended 22.4 to get more output. I will let you know how it sounds....

fudgemik
01-22-2005, 05:44 PM
derek, no need for bass boost at all. you can only boost those frequencies that are higher than your tuning frequency, what that means is your little 1.06 enclosure which drops below 1 after you put the speaker in. you will have problems boosting 60 hertz when your box is tuned at a much higher number which im sure it will be. so maybe a few db's of boost at all. If you want more bass , then add more speakers.....

derekwwww
01-22-2005, 09:21 PM
thanks for the reply fudgemilk. do you think using acoustic polyfill would help worsen or not do anything for my situation?

Thanks

Easy E
01-23-2005, 09:21 PM
Well actually putting a little boost low end might help if you wnat to try to get a little more low end out of the speakers. So play around with the boost see if you like it. Adding a bit if poly filly will create a lower Q for the speakers allowing them to play a bit deeper. Try experiments see if you like it.

By the way Fudgemik statement pretty much useless, yes hes right dont boost bellow tunning only problem is your running sealed so you dont have a tunning. Plus if you did run them ported definately would be tuned bellow 60hz...

fudgemik
01-25-2005, 12:48 PM
Yes thats right you have sealed enclosures, was thinking ported , don't know why? Maybe cause everything i build that I ever liked was ported , anyways? Yes play around with the stuffing, you could easily put it in and take it out..........Have you played the sub yet?