At 06:35 AM 3/17/2009, Phil Keller wrote: >All, > >I am looking for some assistance from the collective: >We are utilizing >PC style amplified speakers and plan on running the leads (most likely >16 gauge "ZIP" cord) back to a centralized location which will be >utilizing an MP3 style player. >* Problem: As I understand it, and I am not an audio kind of guy, the >MP3 player will not be able to drive the 6-12 PC speaker loads, thus the >need for an Audio Splitter/driver distribution system. I may be able to offer some help here. From the above, it appears as if you want to drive multiple amplified speaker systems (with built-in amplifiers) from a single audio source. That should be no problem but there are a couple of things to look out for. 1) make sure that all of the amplified speaker systems do NOT have a ground pin on the power plug. You are running unbalanced audio over a distance and would most likely have a problem with ground loops that would cause hum and other undesired noises from the speakers. 2) use shielded audio cable for your connection between the MP3 player and the amplifiers. I assume that you are sending a stereo signal - that means that you should use a shielded twisted pair cable. A typical cable number is Belden 8450 (solid conductors) or 8451 (stranded). You don't have to use those exact numbers - lots of other cable suppliers make similar cable a LOT less expensive than Belden. But you can use the Belden numbers to cross to other cable manufacturer's part numbers. That's really all there is to it! Oh - if I was doing this, I'd most likely be balancing the audio using some of my transformer cards or active balancing cards but that should not be necessary if your distances are short. You will know that its a problem if you have undesired noise coming out of the speakers that you can't get rid of. Write back if you have that problem. The reason the above should work just fine for you is that modern audio gear is set up for what's called "bridging mode" instead of "terminating mode". Bridging mode connections rely on the audio source having a low output impedance and the audio inputs having a high input impedance. The output impedance of most consumer audio gear is 47R to 100R. The input impedance is usually 10K or so. So: just run shielded audio cable from each amplifier-speaker input to where the MP3 player is located. Put 3.5mm stereo plugs on the ends of the cable so that they can plug into the amplified speaker inputs. At the MP3 player end, just use pigtail splices to join all of the shield, Left, Right conductors together to the cable coming out of the MP3 player. Hope this helps! dwayne -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist