Hangar Flying => Hangar Flying => Topic started by: larry on April 02, 2005, 09:00:40 AM
Title: car stero
Post by: larry on April 02, 2005, 09:00:40 AM
I put a pioneer car stero in my longez for music and I want to listen thru my aviation headset. I also have a King KMA 24H. My volume is very low and I suspect an impedence mismatch is causing the low volume. The volume is ok when running thru 8 ohm speakers. Any ideas??? thanks larry
Title: car stero
Post by: Joe Dubner on April 03, 2005, 07:46:29 AM
Larry,
Your suspicion is correct -- the voltage at the 8-ohm output of the stereo is too low for the higher input impedance of the intercomm. When I did my (mono) setup a couple of years ago I used a tiny 8-ohm to 1000-ohm matching transformer with good results. With a stereo intercomm you would need two transformers: one on each side.
I dislike putting Radio Shack parts in my aircraft or recommending them to others but in this case I made an exception and bought their 273-1380 transformer for about three dollars.
BTW, it would probably be a good idea to put a dummy load (i.e. 10-ohm, 10W resistor) on the output of each channel of the stereo.