Hooking a sub to a computer

RJaco

Not sure what I need to make this work. I was given an Infinity PS-8 sub and want to hook it up to my computer. Looks like it has the three RCA hookup in the back but one says LFE. Was thinking that is where I plug into the sub but where do I plug into the tower? Do I need a splitter or is there a place to plug in? I have a Dell Studio that is about a year old. Appreciate any help.

Tbone289

Are you running your left and right channels from a separate amplifier, or are they self-powered?

RJaco

I have an Adcom amp powering two speakers that I made a while back from a Parts Express kit. Forgot about that, sorry.

gtu2004

you should take a picture of the back of your computer and the back of the sub.

Tbone289

If you're going to do that, take a picture of the back of the amp too.

Assuming that your Adcom is just a two-channel amp, your best hookup option is to run L&R speaker cable from your Adcom to L&R sub speaker-level inputs, then speaker cable from sub outputs to your PE speakers. This will allow you to tweak the low-pass filter on the sub to better match with your PEs.

Another option: If your Adcom has "pre-outs", you could use RCA cables from those outputs to the line-level rca inputs on the back of the sub. Then, you can keep the L&R speaker cables running direct from the Adcom outputs. This may be a "cleaner" cabling option, depending on how your speakers are arranged.

RJaco

Here are pictures of all 3. The cable you see in the picture of the computer is going to my amp.

Tbone289

If you're just running a 2-channel system, I would still use option #1 that I described above.

Usually the orange jack on a 5.1/7.1 sound card carries the LFE/subwoofer output, along with the center channel output. Check the color codes in your computer manual. Basically, if you split the center/subwoofer 1/8" plug into right and left RCA jacks, you would get center output on one jack and LFE/subwoofer output on the other. If you use this setup, be sure that you have configured your soundcard's control panel to output 5.1 audio.

RJaco

"Assuming that your Adcom is just a two-channel amp, your best hookup option is to run L&R speaker cable from your Adcom to L&R sub speaker-level inputs, then speaker cable from sub outputs to your PE speakers. This will allow you to tweak the low-pass filter on the sub to better match with your PEs."

Guess I am just too old to figure this out. What are you calling the sub outputs that will go to the speakers? Everything on the sub looks like inputs to me. The only way I can see to hook everything up is to go from the computer to the sub and then from the sub to the speakers but I would have to hook the speakers to the high level input. That would do away with my Adcom and make the sub amp power my speakers. That doesn't seem right, either. I was hoping there was a way to just hook the sub to my computer like the Adcom.

Tbone289

Oh, yeah. I got that wrong. Your sub doesn't have a pass-through to outputs like Polks and others.

No big deal though. All you have to do then is to run parallel wires from the Adcom to your L&R speakers, and to the sub. In other words, connect two speaker cables to each of the Adcom's outputs (L&R, four cables total). From the Adcom's left output, run one cable to the input of your left PE speaker, and the other to the left input on the sub. Do the same thing for the right--one cable to the right input of the sub, the other to the right PE speaker. Of course, observe polarity on all cables (+/-)

lugtuava

It is just a trial and error when plugging the cable.

DJ Big Jim

Does he have to do it to both right and left? Just curious, can he just do one of the channels since he is not also coming out of the sub to the left/right speakers?

Tbone289

I wouldn't recommend it. In two-channel, the left and right channels are separate tracks, and aren't always going to have the same bass "information" (for lack of a better term). In other words, if the bass is predominately set up in the right of the stereo image, and the sub was only attached to the left channel, the bass would be virtually non-existent.