atcomsystems.ca/forum Forums Computers & Programming Computers, Software, Accessories Laptop Audio Output to Stereo Input?

I want to get audio from my laptop to my home stereo.

I went to Radio Shack today and bought the standard cable and adapter to go from a 1/8" stereo output from my laptop to a 1/4" mic input to my home stereo but I keep getting a roar in the line and after a few minutes the audio is so trashy you can't understand it.

What kind of equipment do I need to get for a clean, quality audio signal from my laptop to my home stereo?

on mine I go from the audio out of my laptop to an aux input or input for a phono or tape player or CD - then keep the PC or laptop volume down to nearly off since it will act as a pre-amp. That works for me, but I don't have a very sensitive ear for fine quality.

You'll get a roar with an impedance mismatch. Your laptop is an auxiliary output, you're trying to go into a mic input. You'll either need a matching xfrmr or else go into the aux or cd (NOT the phono) input of your amp. Try that first.

Sam

Should work fine if you use the proper inputs on your stereo. That's all those computer speakers are. Sounds like the output level from your PC is overloading the input on the stereo. Like Mark said, turn down the volume on your PC and use a line or AUX input, not a low level mic or phono.

-Hal

If turning the laptop volume down doesn't help Radio shack sells and attenuator cable that will allow a audio output like a boom box to go into an aux input.

We frequently use direct boxes to go from a mic input on our mixers to a line level input for laptops. However, on most home audio stuff, you can just use an RCA Y to 1/8 inch stereo cable. Do you have any RCA inputs or is it all 1/4 inch?

Thanks guys.
Yeah Jeff, the stereo has RCA connections in the back. The problem is every slot is used and I don't want to have to switch cables all the time. I've seen the switches for that but I don't want to have a bunch of things to do so I can watch movies from the Internet. My wife says it's bad enough now with the satellite, the basic cable (for when the satellite washes out), 2 DVD players, and the plain old music system.
I think I'll just get a quality speaker system for the laptop and just leave them on top of the entertainment center. That is,,, if I can get away with one more thing in there.

Bobby -

If you have a spare mic connection on the amp, look for a aux to mic matching transformer. You should be able to find one pretty inexpensively at Radio Shack or a Music Supply Stores (Sam Ash - if you have them there)An Aux jack is about 15K ohms (Hi-Z). A Mic jack is about 150 ohms (Low-Z). The impedance mismatch is why you were getting crappy sound.


Sam

Ever consider that the sound from those internet movies is crappy and that's really what your problem is? You don't notice it with those small PC speakers but it becomes painfully obvious with something better.

Your cable should be fine. What I would do is temporarily disconnect the audio from the cable box or a DVD player and plug your laptop cable into those inputs. Those should be the correct level inputs for what you are trying to do. If it doesn't work then there are other problems.

Sam, we don't worry much about impedances and impedance matching any more. The only criteria is that the source is low and the load is high. Usually a line out will be maybe 200 ohms and a line in will be 10K. On consumer gear with unbalanced inputs they will be at least 10K and that goes for the mic input. So the problem here (if there is a problem) is that the mic input will have lots more gain than a line or aux input and that gain is usually before any volume control. So if you feed it with a high level signal, that high gain stage is going to clip and there is no way to reduce the level except at the laptop or inserting a pad between the laptop and input.

That's not a matching transformer which will actually increase the level and make the situation worse (150 ohms to 15K is a step up transformer).

You will need two pads, one for each channel.

-Hal

When I did this, I used an RF FM-Modulator to turn PC audio to an FM radio signal, tuned in to my designated frequency, and had the desired audio on the surround sound.

But, as Hal has mentioned, poor audio has a way of being disguised on the little speakers but may be intolerable on the "finer quality" reproduction.