Hooking up Sony HT-IS100 Speakers & Sub to Sony STR-DG720 Amp

[Ron_Bacardi]

So my parents just got a Sony HT-IS100 home theater setup but the problem is that we want to use the more advanced Amp that we have rather than the built amp on the Sub of the HT-IS100.

I've figured out that we can maybe hookup the speakers that came with the HT-IS100 directly to the external Sony amp; the problem is getting the sub hooked up. Is there anyway of doing this? Or do we have to use the built-in amp within the sub?

 

[Adam]

Welcome to the forum, Ron!

There are a couple of things to consider outside of simply connecting the subwoofer:

1. Those satellite speakers are rated at 4-ohms nominal. That might cause the STR-DG720 to go into protection mode if you crank it up and the current draw gets to be too high. Just something to think about.
2. Perhaps more importantly, the subwoofer has a fixed 800Hz crossover. So, the satellite speakers may not be good at handling frequencies much below that. The STR-DG720 can only go as high at 160Hz for the crossover, so you might not get the performance that you're wanting.

As for connecting the subwoofer, that shouldn't be too difficult. You'd connect the subwoofer output from the STR-DG720, use a y-splitter like this one from Monoprice (you can get them at a lot of places), and then connect the two other ends of the cable to the left/right audio inputs on the bottom of the subwoofer (I forget the name on the input, but I can look it up if you need me to). You'd need to have the subwoofer be on, set the volume level, then level match it to the rest of the system like you would any other powered subwoofer.

If you have questions about any of that, just let us know.

 

[Ron_Bacardi]

Thanks for the advice! I'll probably get that from monoprice. I need the name of the inputs for the sub though. I cant find the exact inputs.

 

[Adam]

Hey, no problem! Happy to help if I can.

On the bottom of the sub, there is an input labeled "VIDEO" that had three RCA inputs: one is for video (which you won't use), and the other two are for left and right audio inputs. Connect the two-ended portion of the y-splitter to those inputs. They are labeled as assignable, but I'm guessing that the default assignment is to the "Video" source selection. You only need to set it once because you will effectively be using this as a powered subwoofer.