Thanks guys, I’ll check both those out. I tried setting the gains with a 1kz test tone and set the volts to 20. I was getting distortion way before 3/4 volume and messed with the hpf. Is that normal? After that I just tryed by ear and now I’m about 11 o’clock on the gain. I even turned them all the way down but still heard the hum but was very faint.

 

There are some good suggestions here and they all should be looked at but if the hum is only audible at a very low volume with the bike off how much effort do you want to put into finding the source of the noise? How does it sound when the bike is running and the volume is turned up? Isn't that where you'll spend most of your time listening?

If you do want to put the work and time into solving this (and I would) then you really should rerun your amp grounds to the frame while you're in there.

(Bates and others please suffer me one more time while I explain my position.)

/rant on

I get it, many of you connect your amp grounds directly to the battery and you don't get hum. That doesn't mean it can't be a source of noise or that it's the correct way to wire your amp grounds.

Consider this:
Physics are real and electricity doesn't read a schematic.
Every circuit on your bike, including the starter motor, uses the ground strap from the frame back to the battery to complete and allow current flow.
Ground straps can fail. (Not likely but not impossible.)
If there is a path for current to flow to complete a circuit, intentionally or by accident, it will.
If the ground strap fails some, or all, of the audio system and the ground leads you've run back to the battery are now potentially the only path to ground for every circuit on the bike.

Now it gets a bit scary:
the main fuse on your bike is 40A (50A on my FLHTK).
this fuse supports the combined current flow of all circuits on the bike while it's running
the starter, when cranking, does not even go through a fuse at all but is directly connected to the battery (under the control of a low current circuit through the starter relay and solenoid)
an 8 AWG ground wire can support a current draw of between 20 Amps (43+ strands) and 70 Amps (solid core)
IF, and it's a pretty big if, the path to ground (your audio system via your 8AWG ground run) were to survive the 150ish Amp surge of the motor cranking over (it's 200A max cranking current on my FLHTK) the running current draw alone could overheat and melt your ground lead's insulation possibly leading to a fire (maybe under the gas tank). It could also take out any electronics in the path to ground before the wire got hot (maybe that's just your amp or maybe not).

If you think I'm being dramatic why not try this:
Leave the amp ground connected to your battery
Disconnect the ground strap between the battery and the frame at the negative post (I'd remind you to tape the bare end of the strap but it won't really matter)
Try starting your bike.
If you're lucky no circuit (other than power to your amps) will complete, everything on the bike will be dead, and nothing will happen. But if you're not...

Remember:
Just because your buddy or audio installer runs amp grounds to the battery doesn't make it correct. (I'm sure everyone's Mom said at one point "if so&so jumped off a bridge would you?")
Always do it the right way because things that never happen sometimes do.


Reference:
Soundstream Picasso Nano Amp Owner's Guide (see page 3)
2007 FLH wiring schematics (see page 5)
AWG Wire Gauges Current Ratings (from Engineering Toolbox)

/rant off

 

Holy hell would you LET IT GO?? Sheesh. Offer suggestions and stop with the rants and non stop you're wrong I'm right EVERY single thread!

 

Ok, I'll let it go and promise never to bring it up again... if you can tell me why grounding to the battery is a good idea. I've asked over and over again and I get nothing back from any of you. Do you know why you do it? If so tell me. Otherwise, I'll stand by my position and call you out as someone that doesn't know wtf they are talking about. Stop recommending a dangerous practice to people that are looking for advice while posing as someone with knowledge that you clearly don't have.

Here's my suggestion to the OP. If you don't at least think I have a clue about what I'm talking about then keep doing what you're doing. Don't worry about a hum at a volume setting of 1 that is inaudible when you turn it up or the motor is running. It's irrelevant.

 

Well you did ask for one instance where an amp manufacturer suggested grounding to the battery and that info was provided yet we're still here going back n forth over this. I have yet to have a hum due to grounding directly to the battery and I've done quite a few installs. It's always been either a bad RCA, gains set too high, or HU set up improperly and overdriving the amp and even LED lights and brake modules causing issues.

 

Are you even reading what I'm saying here? It's NOT about the hum that I'm suggesting you DO NOT ground your amp to the battery. It's a safety thing. Pure and simple.

I don't doubt you've done a lot of installs and that you've not yet seen hum as a direct result of grounding the amp to the battery (but it does happen). But you've also never seen what can happen in high current situations where the only return path is accidental and unable to support the load. I have. It's unforgiving and instantaneous.

My offer still stands. Tell me why you guys think it's a good idea to ground your amps to the battery and not the frame. I'll rebut your points and then I'll drop the issue. Obviously how you choose to do your install is up to you but if you don't know what you're doing please don't give potentially lethal (to the audio gear at the very least) advice.

(BTW that RF install advisory is incorrect. The entire premise of that bulletin was about poor grounding going through steering head bearings which doesn't happen on any bike if you pick an appropriate ground point on the frame. The correct way that advisory should have been written was to advise to not ground to the bars, triple tree, or fork assemblies and NOT to the battery. That was just lazy, shitty technical writing. But granted, it did meet my challenge)

 

This forum needs an "ignore arrogant, know it all jerks" button.....

 

This shix is beyond my non-audio brain, but I did find this, 3rd reply: https://www.hdforums.com/forum/audio...-question.html

 

Good find.


From Alex(haze), arguably THE best in the business.....well when he was in the business. So I trust him and others here more than this "educated" know it all. I think this settles it....
"From another post. Read Fosgates amp install guide it specifically recommends the battery on motorcycle installs.

"It's a resistance issue... resistance = total area of the circuit or wire... with a wire, you can calculate resistance as length X diameter. So, a shorter wire will have less resistance. The basis of the short ground wire is from the early days of car audio where a high powered amp was pushing 200W. The typical power wire was 8ga. Compard to 15ft of 8ga wire the chassis of the car (whaich was quite substantial in the 80s) is of low resistance. Look at where we are today. A modest system has over 1000W and the primary power wire is at least 4ga if not 0ga. At the same time the metal of the car itself has gotten thinner and as such a worse conductor. Length doesn't matter. Resistance does. As long as the ground is of low resistance, there won't be an issue. The same goes for the power wire. If you are looking at using 0ga for the power wire, you will proably get a better ground by going straight back to the battery with the same size cable.""

 

what this forum needs is a BS filter to stop people like you giving bad advice.

Read that thread and sure, copper is a better conductor, so what? We aren't talking about the resistance of your ground. We are talking about running a path to ground in parallel to the ground strap that results in an unintentional path if that primary path should fail. We are talking about electricity 101, pretty basic stuff.

Did you try my simple test? Go on out to the man-shed right now and give it go. Remember this thread? See post #9. Assuming his amp was touching metal, and he's also run his amp ground to the battery, I'm pretty damn sure that ToddOH would NOT want to try my test.

Still waiting teedoff...what's the reason I'm wrong?