Ok guys need some input. Just installed 6.5 speakers and pbr300 amp. Everything sounds great except for when the radio is on and the volume is very low with the engine off i hear a very low hissing sound. sound modulates a little with turn signals and other electrical inputs. Cant hear it at all with music going or engine on. Also it goes away with radio off. My ground is run to the battery per the instructions in the pbr300 manual. There are a couple other factors at play here as well as I believe my battery took a crap sitting over the winter and I tested everything with the charger hooked up (but get the same noise with it unhooked but my batt is definately bad). Will get a new battery tomorrow as its going to be 70 and i want to ride..... Another factor is I just installed the new iron cross bluetooth mod that hooks directly into the radio and makes the radio bluetooth compatible. I got the power and ground for this from the extra power/ground on the headlight loom, just plugged right in. I dont remember the hissing when i tested the amp before i hooked the bluetooth up but no sure. Could i be getting interference through the bluetooth module because of where i got the ground/power from the headlight harness or is there any chance the battery voltage is so low that it is creating some interference. Batt voltage is 12.5 but drops to 5 when i try to start..

 

Replacing the battery is definitely the first step. If the hiss continues try disconnecting the Bluetooth module. What are the gains set to on the amp?

 

gain is just north of 5

 

Minor hiss is typical. I main minor. Close proximity and long grounds. commonly referred to as floor noise. Some amps have more than others but isn't uncommon,

 

yes it is very minor. doubt anyone would notice. my brother did t even hear it until i pointed it out

 

My micro 2v2 has done it since day 1..i havnt rode much if any since the install so I also havnt tried to track down the issue.. My responses were different than yours though lol. The times I have ran the system I've had zero issues caused by the minor hissing.. This month is ill have an all new 4 speaker 2 horn set up so maybe I won't have to deal with any issues at all lol

 

So far I see no issues from the hissing I can't hear once I turn the bike on but I am just particular I guess. Headed to get a new battery this am so we will see if that makes a difference

 

could be that you need to increase the volume on your head unit and reduce the volume on your amp

the idea is you want to head unit volume high enough to provide more music that noise ( signal to noise ratio) without distortion

and then use the amp to amplify that to desired power level

Mike

 

Didn't think about that. I will try that tomorrow. To nice to be in the garage today, going to ride........