Ground Noise In My Audio System

[tcfjr]

I got my '05 ABS in August of 2004. Early on, I started putting together an audio system, with the goal of feeding an MP3 player (iPod Shuffle), a Valentine V-1, and an XM Roady2 into a single source for listening through in-the-ear headphones. Since the beginning, I've had problems with ground noise, and I have had no luck so far. If anyone has advice, I'd really appreciate it.

For power, I have an SAE connector wired directly to the battery terminals that connects to an outlet on my tankbag; inside the tankbag, there's a power block with 4 positive and 4 negative terminals. I also have power blocks installed per the FJRtech article, with an 8-position positive block under panel B, and an 8-position negative block under panel C. All wires are connected to the power blocks with crimped and soldered spade terminals, with a relay connected to the front-right running light controlling power to the positive block.

The V-1 and Roady are connected to hardwired connectors attached to the under-panel power blocks; these power blocks also feed power to the Magnum Blasters (through relays)

My first attempt was with a MixIt. I connected the MixIt hard-wire power plug to the power block inside the tank-bag and got incredible ground noise - even with no external audio sources connected. Connecting the V-1 caused the ground noise to shoot through the roof. The noise varies with the RPM of the engine.

Next I tried an xma3 - same problem, although the ground noise only occurs when one of the external devices is connected. The xma3's design limits the effectiveness of the V-1 audio signals, making it difficult to get the full benefit of the V-1, so I decided to move on.

Now, I have an Amplirider. It's connected to the tank bag power block, and has great sound quality. (Even under 9-volt battery power, the MixIt's sound quality has been somewhat poor, with a lot of background hiss; the Amplirider's sound is almost noise free.)

When I connect the iPod (running off it's internal battery) to the Amplirider, everything works great - exactly what I'd hoped for. However, if I connect the Roady to the Amplirider, I get noticeable ground noise - not nearly as bad as the MixIt was giving me, but way too much to deal with on a long ride. When the V-1 is connected, it doubles the ground noise; I've heard the V-1 is well known for generating this kind of noise.

I discussed this problem with the Gary, the guy who builds and sells the Amplirider, who's been very helpful. Based on his suggestion, I changed the tankbag so that the negative feed to the tankbag power block is now connected to the same negative power block that the V-1 and XM connect to. In my tests, this changed the character of the ground noise somewhat, and maybe reduced it a little, but it's still there.

Now, I know that there are a bunch of people successfully running XM's and V-1's on their FJRs through both MixIt's and Amplirider's, without the ground noise problem. There must be something on my particular bike that's causing the ground noise to be so bad, but I'm not sure what the next step should be.

Gary and I also discussed ground loop isolators, but he felt that I'd be unhappy with the reduced frequency response, especially from the XM.

Sorry for the long post, but I couldn't think of a shorter way of getting all the relevant info out. Any ideas would be greatly appreciated.

 

[dobias]

tcfjr,

I'm surprised you haven't had a power filter suggested to you yet.

I added a simple 20 amp Radio Shack capacitor between the battery and my intercom equipment. It made a big difference. This winter I'm going to replace the power lead with a shielded conductor from the battery to the accessory fuse & terminal block under the seat.

dobias <_<

 

[slapnpop]

I've done car-audio sound quality competion, and have some best of show trophies. Here's my input.

Run the grounds for ALL of the electronics that connect to your audio system to a distrubution block, then from that distro block to the battery's negative terminal. This ensures that all of your electronics have the same ground, and no voltage differential can occur between various grounding points, which causes noise.

 

[BrunDog]

What SP said.

-BD

 

[Woodstock]

I've done car-audio sound quality competion, and have some best of show trophies.

I suppose I'm the only one to find it somewhat disturbing that someone gives out "show trophies" for car-audio sound quality. :erm:

 

[dobias]

"I've done car-audio sound quality competion, and have some best of show trophies"

This begs the question, what is the prize? Is it a hearing aid?

dobias <_<

 

[FJRandy]

Boy, no respect on this thread. Eh Slapnpop? They don't know what they're missing. :bleh:

Yes tcfjr, ALL grounds should go to one central point, namely the neg batt terminal. No exceptions!

BUT.....this won't solve your problem. BTDT! You NEED some sort of filter capacitor on this bike for some odd reason. It seems no matter how well you ground, once you connect more than one item you get a ground loop. It's very possible the lines are picking up RFI from the coils when you run wires near them or under the tank.

My system is noise free until I plug in my CB radio. Then I can hear exactly how my motor is running! As far as mine is concerned, I'm betting the CB is not internally grounded well for the antenna's sake. Portables allegedly cannot have a grounded antenna. (I don't believe it, but so I'm told)

I live with it...keeps me from dosing on those long slab rides.

Yes slappy...I'm in the business too.

 

[FJRandy]

Oh, one most important thing.

MAKE SURE you don't secure your ground block to metal! I don't know which one you're using, but if it's all metal and you screw it into a frame rail or some other metal part.....instant ground loop!

 

[motorgod]

I ran a negative wire from the battery, my GPS, my Starcom, and my XM radio, connected them all with a wire-nut....this way I was sure they were grounded to the same spot. No noise here (or hear)

 

[slapnpop]

"I've done car-audio sound quality competion, and have some best of show trophies"
This begs the question, what is the prize? Is it a hearing aid?

dobias <_<

There's difference between sound quality competitors, and those big ugly trucks that go boom boom. My car won't even hit 130dB, which is mice nuts to those guys. When judging a sound quality system, the volume averages 80-90dB. This is the volume my system is properly tuned to.

 

[dobias]

slapnpop,

With your "ear" for quality sound, what is your choices for intercoms, headset speakers and earphones?

I'm no longer able to appreciate all of the differences but I'm still curious to know what's good reproduction equipment.

dobias

 

[slapnpop]

slapnpop,With your "ear" for quality sound, what is your choices for intercoms, headset speakers and earphones?

I'm no longer able to appreciate all of the differences but I'm still curious to know what's good reproduction equipment.

dobias

To be honest, I haven't fully tackled this on the motorcycle yet. I've got the Ipod, which I like as an on-the go music source, but my helmet has no room for speaker or microphone. I've also started riding with earplugs if I'm not just around town or commuting a short distance. I'm eventually going to a get a custom molded ear plug/headphone set for work anyway (too much noise), and I'm getting the kind that doesn't stick out of your ear far.

I have no comm system, so I am experienceless(?) in that area.

 

[dcarver]

The printed brochure from Aeorstitch has a good section on audio/comm earspeaker/headphones.

 

[dobias]

slapnpop,

My Shoei Z-2 helmet wasn't made to accept earphones nor a mike. I carved out space for them. Being extra careful, I succeeded in a very neat job and they work well. Location of the speakers is of extreme importance, as is the location of the mike. I still plan on adding earphones with an adaptor cable for longer distance rides.

The Softline I have gives me a very quiet background for the communications and music by virtue of their MANR noise abatement system.

dobias <_<

 

[sparky3008]

Has anyone considered these?

https://www.clearercom.com/Helmetspeaker.htm

I have an HJC helmet that seems to have room in the ear sections for these.

Also is riding with music distracting for anyone when it comes to being able to hear what is going on around you?

In my truck I have a decent system with 2 10" subs and love bass so most of the time I can't hear what's going on in my truck either but I have never ridden a bike with music in the helmet only on a harley with speakers...

Thanks