dsharky

Hey gang!
I have a problem. I have a Technic DD/DTS decoder and 5.1 speaker setup at home with DVD(your normal setup). However, i bought the subwoofer seperately and it is NOT A POWERED sub. Basically, it will not channel out any sound to the subwoofer at all. I tried plugging in a powered sub and the whole system works perfectly.
My question is, How will i get a NON-powered sub to work with my decoder? is there some kind of amplifier or some little gadget i can buy at radio shack that will make the sub work? Those guys at radio shack has no idea what the heck i'm talking about. PLEASE HELP!!!

GregSoundBoy

just buy a subwoofer amplifer and hook it up to your passive subwoofer. run a sub cable from the sub out of your receiver to the "in" of your amp. you'll be set.

dfcc

Just go into your 5.1 setup and say you have no sub. This will allow the LFE signal (all the bass) to be sent to your front/non powered sub. This should work just fine.

jumbojp

I have two passive subs and this is what I do.
1. Run a split RCA from the sub out/LFE out to the amplifier.
2. Run 12AWG wires from the amp to the subs.

You don't mention anything about using an amp between the receiver and the sub. Do you have one?

dsharky

thanks for the advice. See, i already have the passive sub(is that what theyare called?) . and i just wanna get it to work? so from what i understand. I NEED A SUB CABLE?? Is this a different type of cable then the normal Yellow/REd/white ones? I'm not good with terminlogy. and what is a 12AWG??

Jumbojp, i already have a ampilfier with built in decoder(DD/DTS). It's just not channeling any sound out to my non-powerful subwoofer. Please continue to clarify to this confused guy here

jumbojp

You need a power amp to drive the passive sub. The RCA output from the receiver won't supply any power to drive it. You need to run the sub cable to a power amp and then the speaker cable from the amp to the sub.

Here are the connections:
1. Sub out on your receiver/decoder using RCA cable to a power amp.

2. Speaker cable from the power amp to the sub.

Basically unless your receiver/decoder has a sub amplifier built it to it(very unlikely) you need to buy a seperate amp to power the passive sub and connect it as shown above.

12AWG just means 12 guage wire. It refers to the thickness of the cable.



[This message has been edited by jumbojp (edited September 14, 2000).]

dsharky

thanks jumbojp
Here's the question then since you're the expert here. how much are the powered amps? do you think it's worth it to get a powered amp+ the sub cable or shhould i just go and buy one of those $100 power amps and like try to sell my passive sub for like $30 or so. Thanks for all your help. you've made things very clear. too bad i can't return this sub that i bought...stupid me.

jumbojp

I guess you have 2 options:

1. Sell the passive sub and buy a powered/amplified sub to use with the receiver.

2. Buy an amplifier to power the passive sub you already have. If you do this you have a few options. You could get the type listed below which bolts directly to the back of the sub box, but you will need to cut a hole. This type of amp is what comes on a normal amplified sub: http://www.partsexpress.com/pe/showd..._ID=9387&DID=7

Or you can get a component style amp that you put in your rack with your receiver. This is a little bit more complicated, but I think it is more flexible. I use a 2 channel component to power my 2 subs. http://www.partsexpress.com/pe/showd..._ID=5442&DID=7

*these links are just examples

Either way you need a basic RCA cable to run from the LFE/sub output on your receiver to the amp. Regular RCA cables work fine you don't need a special "sub cable".

If you have a Home Theater shop in your area you should talk with them. They may be able to explain it better and draw it out for you. Good Luck

MichaelBlanton

Doess your current amp/receiver have dual speaker outputs for the 'mains' (my Yamaha does--A+B)? If so, another option nobody mentioned would be to connect your passive subs to the "B" jacks and let the amp/receiver you currently own drive them. In this setup, you'd also need to do what dfcc said and make sure the LFE stuff gets redirected to your mains, which in this case would be your mains on output "A" as well as you subs on output "B".

jumbojp

MichaelBlanton,

If dsharky does that there would be no crossover for the subwoofer. It would be getting full banwidth and it would probably sound horrible.

electronix_kid

I have a passive sub, and this is exactly what i do:

From Receiver's Sub-Preout, 1 Audio Cable.

Audio cable goes into l/r RCA input of seperate power amp.

L/R speaker out using 1 pair of speaker wire (depending on where you hooked the RCA cable to on the amp)

speaker wire to Subwoofer.

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DNMonty

Hang on I gotta get my 2 cents in.
Scenario 1:
If it is indeed a passive SUB, it would have speaker level inputs and high-pass outputs. If you connect the sub to your receiver, you fronts to the high pass outputs, you're set. LFE will not do anything and you set your receiver to "no sub" and "big speakers"
Scenario 2:
Dump the passive sub and get a powered one and you will have the ".1" of your 5.1 DD You would tell your receiver you have a sub and set your fronts as what they are. (big or small)
Scenario 3:
Your passive sub isn't really a passive sub but just a box with a subwoofer in it. (no crossover) in which case, if you go scenario 1, it'll sound like crap.
But if add another amp to amplify separately and can crossover the signal you are essentially running a powered sub then and are golden. If this is the case, check out http://www.partsexpress.com/pe/pshow...=300-800&DID=7 they have an amplifier you can add to your, plain box sub to make it a home-made powered sub.
Hope this helps.

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Sony 32" Trinitron
Onkyo TX-DS575x
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JBL Music1 mains, Phase Technology 1C center, Advent Baby II surrounds, Infinity BU-120 sub