Idea!!

I want to make a hometheater sub, Im thinking of doing 4 10 inches, in a sleaed box, wired into a 2 channel amp. so first off, thats possible right? also, what is the best type of amp? cause eventually I want to be able to take two of them out and make somthing really cool, and comp,icated and turn the toerh two into car speakers, but that will be later.

note, this sytem is for mostly music.

so, what is the best over all sub? I want something good, affordable, and reaidly avaible since I will need to be buying 4 of them used.

K a few things.

1) Car Audio runs on 12V DC
2) Your house (and home theater subs) run on 110V AC
3) In Home Theater systems, the reciever is the amp
4) Different Connections

now, i dont know how in the workd your oging to try and do this, even with an AC-DC convertor, it would be pretty weird. not to mention that home theater recievers have a sub-out coaxial (or sometimes digital) cable, so i dont think the audio connections would work. it doesnt use an rca from stereo-to-amp like car audio, but the home theater reciever is the amp as well, with a single connection to the sub, not like your + and - wires for car audio.

well, home theater subs, are usuualy externally amped, as in, the reciever really isn't an amp as far as the sub is conerned.

Secoundly, the reciever send the line for the sub through an rca able, I know cause I have ran an rca cable through their when cash was tight, so I don't see the problem all I have to do is get the converter.

even if the singal was coaxial evr heard of a line out?

besides that I have the amp mountd on the box and big deal, its great and I have four sweet looking subs under the desk.

even though it may work, i think you would get better quality out of a home theater sub using a digital signal. thats my opinion

Since you are looking into buying something new anyways, i think you may find that by the time you get 4 subs and a monster amp, you'd be saving some money by buying a high-quality home theater sub

I am almost certain that most car audio subwoofers that are HQ handle much better than home stereo. Home stereo lacks the umf.

Home stereo lacks the umf? You need to listen to more home stereos systems then. I have a Velodyne 15" with 2k watts on it. And I heard ALOT louder than mine. I have 60k in my home theater and that is squat compared to what is out there.

Jdrumstik...sure you can use car subs for your home. BUT a car sub is designed differently than a home sub. That does not mean it won't work though. Yes you can get a big power inverter to run a car amp in your home but honestly I would purchase a home amp to the job.

why in the world would you WANT to use 4 10" subs ? One of the trade-offs car stereo subs make is they can play in a much smaller box ... BUT they require much more power. Just use a 15" home sub and be done with it.

Well, im gong for quality, a 15inch sub puts out better notes but the tranisent sucks. But I am considering a dual 15 setup on a home amp.( ie got lots of books coming in the mail)

and as opposed to hometheater doesn't have the umph. yeah, I agree, home is so dang pricy that most people have these little crap setups.

by they way, where can I buy a resonable home amp around 500 watts and 4 channles?, that would be a "power amp" right and then I would use my reciever as a "pre amp" right?

Well, im gong for quality, a 15inch sub puts out better notes but the tranisent sucks. But I am considering a dual 15 setup on a home amp.( ie got lots of books coming in the mail)

and as opposed to hometheater doesn't have the umph. yeah, I agree, home is so dang pricy that most people have these little crap setups.

by they way, where can I buy a resonable home amp around 500 watts and 4 channles?, that would be a "power amp" right and then I would use my reciever as a "pre amp" right?

15's don't have worse transient response, I swear to god if one more person goes off about this myth I'm going to explode

Home theater isn't that pricey, a home setup costing a certain amount would cost ATLEAST 5x that to reproduce in a car.

You can get a home receiver anywhere, and the receiver is the power amp and the preamp all in one. You don't need a separate amp, in fact there are very very few stand alone power amps out there, and they're for insanely high end setups and cost a lot more than you would want to spend.

well, you don't need 5 million watts in the home like you do in the car. And you're right, transient response is more a function of the box type - most guys port or band bass 15's for xtra bass.

15's don't have worse transient response, I swear to god if one more person goes off about this myth I'm going to explode

H


but i heard the best buy man says 15s are only for rap :eek7:

Well you know if you put a sony xplod sticker on that 15, you get even more rap bump.

Thats actually really cool if you think about it. I have an extra reciever, I could wire it into the subs if I found some 8 ohms which arn't that uncommon, you can buy them on homethater DIY sites.


so then I have a question. If the reciever is 8 ohm, putting out 100 watts to all 5 channels, then, is there anyway to double wire it so that I have 200 watts to 2 channles, and then forget about the 5th one?



also, if Im pushing a lot of watts throhg 15's, then whats the deal with my regular spakers, are they going to be way over powered by the subs if I port them? Or, is that where tunning comes in so i just tune them down to lower frequencies? If I do run them off of there own reciever, then I could easily adjust the volume I suppose.


Well, Im getting real excited keep feeding me with idias.

and some one tell me about wire a 5 channel amp into 2, and forgetting aobut eh 5th channel. Or any idias, for the 5th channel?

Well first off, the receiver puts out the full range to the channels, and the sub would need a lowpassed signal to sound right. Otherwise it would sound muddy and crappy, and would really defeat the purpose of having a sub at all since it would just sound worse with it than without.

Also, the receiver puts out different signals to the different channels, the front R and L don't receive the same signal as the rear R and L, so your sub would be playing the little surround voices and whispers that give you the surround sound effect, not the actual subbass frequencies that go with what's happening on the front channels.

so you are recomemeding the front cahnnels, as opposed to the back.

First off though, I would be using the sub pre out on my main amp, double it into stero plugs (but really just palying one channel) and then run it through, so since my main reciever has all the eqs for a sub, a low pass really isn't needed, since eseentiually the main reciever low passes the singal and sends it to the sub reciever, which will just recieve the sub signal.

plus, my recievers you can set it up as large rears if you want, I play 4 KLH tower speakers pushign 12inch woofers all the way around. I knew that one day I would be playing surround sound DVD audio. So I can't tell you for sure that the rears play little dinky "surround sound" plus my reiceivers have options for various types of surrounds, but you might be right still

so getting the right singal to the subs is no problem at all, atleast I don't think. The real question is, is there anyway to wire a 4 channles amp (ommiting the center channel) into a 4 ohm signal, stereo. Like can I wire two channels into one driver?

also I know this is old, but If I am pushing two fifteens, and listen to grunge/ punk/ indie, then would proted be a bad idia? or if I have the pass low enough, does it not matter. I have heard that ported is only good for rap, but I think that this may be a myth, as all my hometheater stuff is ported.

Thanks a lot, sorry my post is so long.

anyone know of any good sites for 8 ohm sub drivers?

So you have TWO receivers? If so then it would work, I was thinking you wanted to power the sub and front speakers with a single receiver.

And you can run a single sub with 2 channels of the amp, you would need a sub that has dual 8ohm coils though. Both the Adire Shiva and Tempest fit this requirement. Actually a tempest running off of 2 channels (so it would be getting 200 watts) in a 6-7cf box tuned to 20hz would sound amazing.

And ported would be just fine for grunge, punk, etc with a 15.

whew, I'm excitged, and that 6-7 cf box is just what I was hoping for, I want to fill the entire area under my desk with a custom sub box. so are those drivers you mentioned for 8 ohm home audio?

also, Im really excited, so then I coulod run the voice coil off of the rear channels right? and what does a voice coil do anyways? And what if the rear sounds are little and stupid like you said? And should I selct the voice ciol leads as a small speaker?

also, Im thinking of building a custom couch and putting it in front of the subs, would that sound muffled, and crappy? Im also considering building the couch on top of the sub enclosure.

let me know what you all think. I'll be sure to send pictures once I get this thing rolling. I should pull in about a hundread bucks this thursday alone.

thanks a lot.

as for the couch; it depends on what kind of couch. In a car, the best interior for sound quality is as follows:
cloth.......leather, vinyl.

any couch may muffle it some, but leather would have less of an effect. and keep in mind that a subwoofer transmits non-directional sound, so long as it can move the air immediatly around it, your good

whew, I'm excitged, and that 6-7 cf box is just what I was hoping for, I want to fill the entire area under my desk with a custom sub box. so are those drivers you mentioned for 8 ohm home audio?
They're both dual 8ohm, so you could run one voice coil on each channel and it would work

also, Im really excited, so then I coulod run the voice coil off of the rear channels right? and what does a voice coil do anyways? And what if the rear sounds are little and stupid like you said? And should I selct the voice ciol leads as a small speaker?
You could run the voice coils on separate channels, but I wouldn't run them on the rear channels because those are devoted to surround sounds. Then again if you have two receivers you could run them off of whatever channels you want on the 2nd receiver, you would just have to split the sub out rca from the first receiver and run it to the inputs for whatever channels you'll be running the sub off of on the 2nd receiver.

also, Im thinking of building a custom couch and putting it in front of the subs, would that sound muffled, and crappy? Im also considering building the couch on top of the sub enclosure.
As long as the couch doesn't completely seal around the outsides you should be fine, you want the cone of the sub and the port to be completely free from obstacles, and then you need the air all around to be able to spread to the rest of the room easily. If you block it then you effectively create a bandpass enclosure for the sub and it won't behave very well.

so the couch is good, jsut give it some room from the sub, so then, on the voice coils, I guess I should wire them to the surround speakers outs, but then feed it a sub signal, and then set the crossover at zero right? or is that not the idia. Also for a 15inch dual, will I have to use like 1 inch fiber board? And how much will that cost?

okay, so im almost done, what does a voice coil do, and would it be alright to hook it up to the rear channels, and you are right, it sends all the little trickly sounds back there, and might not sned any at all since it will be a sub signal. So would it be alright to hook the voice coils to the rears? and what if I don't connect them at all? WOuld that screw up the woofer? And waht about a non voice coil woofer, maybe cheaper?

The voice coil is the heart of the speaker. The way a speaker works is pretty simple, you basically have an inductor (coil of wires, aka voice coil, essentially an electromagnet) sitting inside a permanent magnetic field. When current passes through this coil, it creates an electromagnetic field that interferes with the permanent magnetic field and it pushes the coil up or down depending on the polarity. Since sound/music is AC, that means the current is constantly switching direction, meaning the electromagnetic field is constantly switching polarity, which means the coil constantly oscillates up and down, basically vibrating at the frequency of the switching. Attached to this coil you have the voice coil former, which is basically just a tube that connects the voice coil and the cone, so as the voice coil moves up and down it pulls the cone with it.

Really in a traditional speaker all you have is the voice coil, cone, and permanent magnet. Then you have the suspension (spider and surround) which keep the cone moving linearly, and the basket that holds it all together. Without a voice coil you don't have a speaker, so there aren't any "non voice coil woofers" really. There are a few speaker designs out there that operate completely differently, but there are very few and most of them are in the experimental stages.

so in that case its a bad idea to wire the secound vioce coil on the rear channels? Or, if the rear cahnnels just don't get much of a signal since its just a surround sub signal, then its like havinga isngle coil speakers right?

so in that case it will work fine either way, weather or not the rear cahnnles/ secoundary voice coils, and d9inky surround sound type signals, it will still sound fine since the only signal is sub

If you already have four 12"-based speakers (KLH) and you're adding a sub, I would say you definately want to make your own box for the sub-woofer system. Almost all commercial "sub-woofers" are geared to go down to 50Hz, or 30Hz if you're lucky and get one with a 15" driver. Your KLH's probably already handle 40Hz just fine.

The purpose of making your own box would be to make the system respond all the way down to 12Hz-18Hz. This can be done, using a ported enclosure, with pretty much any sized woofers. The bigger the woofer, the louder the sound. Speaker size determines acoustic power, and box design determines low-end response, for the most part. For smaller woofers, the price you pay for making them go lower in freq, is they lose power handling. Since your making a sub to go with your KLH 12's, I would recommend at least that size for the four subwoofers. 10's may cone up a little short.

I have a pair of speakers I made for home that use 6" drivers, which go down to a solid 32Hz. It's just that, even though the little Peerless woofers are rated for 60watts, they can only handle about 25or30wwatts in this configuration. The bass is very clean though.

"Ported enclosures are only good for Rap" is a MYTH. Do not listen to anyone that would say such a thing, this is laughable!

I agree with sr20de4evr that "15's have worse transient response than 10's" is a myth. This is only true for modern speakers - there was a time that this was more-or-less true. I'm old-school, so I still go with an array of smaller drivers to handle string bass and lower piano notes, but I've heard 15's do great with the same material.

As for the 4-channels-into-2 thing, you may want to consider using dual-coil subwoofers. That's the short answer. I've never seens a hone-amp that is bridgable.

If you're looking for a new amp, I would strongly recommend looking at pro-audio gear. A several-hundred-watt power amp can go for as low as a couple hundred, and would be of better quality than a "home" unit. They are also commonly bridgable.
Good luck!

If you're looking for a new amp, I would strongly recommend looking at pro-audio gear. A several-hundred-watt power amp can go for as low as a couple hundred, and would be of better quality than a "home" unit. They are also commonly bridgable.
Good luck!


There are several cheap and moderately powerful plate amps on partsexpress and rythmik audio that could power a sub well also.

I really don't know what to tell you about wiring it up, I mean I've never done this or seen anyone who did this, so it's all new ground as far as I've heard. The tempest is a dual 8ohm sub, so wiring each coil to each channel will not hurt the receiver, but I really don't know what kind of signal it's going to be receiving. I say just go for it and see what happens ;)

agreed, okay, Im done. I'll get picture up once its done, but as im short and cash and looking for work? expect to see me starting the box ina month or so.