imbest123

I have an AVIC-D3 that seems to be reading my voltage incorrectly. In K-Pro my voltage shows a constant 14.2V down to 14.1V if I blast my sound system when there is deep bass. Ive been looking at the voltage over on this in dash gauges in my avic but it reads constant 13.5V when cruising, 12.5 - 13.0V when playing music and a constant 12.5V when playing a song with hard bass or raise the volume pretty high. Now I know kpro is showing an accurate reading soooo.... what is my avic displaying? Could that low voltage be from a loose connection/ground or do head units get readings that low? I know its nothing serious but Id like to have everything matching and operating correctly.

I do understand that there are several reasons why voltage drop can occur and that both these power sources are drawn from 2 different wires but shouldnt i still see consistency in the voltage?

nsxxtreme

Ok I had to google what the heck a K-pro was. A little more explanation on your end might have resulted in a few more replies.

The voltage differences may have to do with how the voltage (average,rms) is sampled and how often it is sampled. When you measure something with a DMM you are getting the voltage measurement over time. The device is continuously sampling the voltage and then giving you the RMS voltage in real time. Your radio may only sample the data once per/sec or even slower and then give you an average. So it wont be able to show changes in voltage unless they stay that way for a while. While your K-pro is probably way more accurate since it already has a fast processor in it and it can spend more time sampling data without breaking a sweat.

Its no surprise that a radio would have a slower voltage sampler.

imbest123

thanks and sorry, im on clubrsx nonstop and everyone there knows what k-pro is. force of habit i guess lol. for those who dont know, k-pro is the most widely used tuning solution for the rsx where i can datalog my cars info for tuning purposes. a daughterboard is soldered onto the stock rsx ecu.

that pretty much clears it up. thank you for responding

Duane_in_Japan

Do you have a nice fat capacitor to help out with some of those heavy bass loads. Did you upgrade your alternator and battery to handle your heavy sound system. Doing some actual voltage drop testing would be my first line of diagnosis in this case. What does your multimeter actually show at the power pin of the K-Pro and your audio system, forget the readouts for the moment.

imbest123

i really dont want to sound like a dick but from what ive read on several car audio forums, capacitors are pointless and the big 3 should be considered for more consistent voltage readings, alternators dont need to be replaced for 300wrms and my 2 month old 660cca battery is more than enough to support this sub. im not saying it will stay at the same voltage, just that upgrading a battery and alternator sound to something more than what i have is definitely not worth thecost.

i didnt read the multimeter at the audio system but thats a good suggestion. ill check that out. from the battery to alternator it reads what my ems tells me, 14.2V