Think I could use help running my Crown XLS 1502's correctly

[AcuDefTechGuy]

A third prong is used to reduce the risk of electrocution in gear that is not double insulated.

It's just as easy to get ground loops in two plug and three plug circuitry.

In my previous house when I got Ground Loop Hum, using the cheater plug to avoid the 3rd Prong always eliminated the Hum noise.

Are all AVRs double insulated? Is that why they don't need the 3rd prong?

 

[GrimSurfer]

How do I or where do I download them and just for learning how does it help diagnose this? Even though this is a problem I'm really learning a lot from you guys sounds crazy but I'm grateful

Google "test tones". You'll find a few sites that have just about everything audible posted. No need to get fancy... listen to them on a laptop or PC. As long as they are above 50 Hz, they should be audible (computer speakers have a really difficult time with low frequencies).

I'd suggest 50, 60, and 70 Hz. Then 100, 200, 400, 1000 Hz to start.

You probably don't need to go higher than that because your mid range is picking it up most of all.

Once you find something close, try to narrow things down by going either side of the frequency. It doesn't need to be a perfect match, just really close/similar.

 

[GrimSurfer]

In my previous house when I got Ground Loop Hum, using the cheater plug to avoid the 3rd Prong always eliminated the Hum noise.

Are all AVRs double insulated? Is that why they don't need the 3rd prong?

Any electrical device sold legally to consumers in the US that does not have a ground plug must be double insulated.

 

[Ponzio]

Well, if you have a Yamaha AVR, then you must buy a Yamaha PX3 amp for Synergy. LOL.

But seriously, if you always wanted to try, you can order one from Amazon and return if it doesn't work out.

True.

It's been in the back of my mind now for the last couple of years. I'm a big believer in more power, the merrier. I've noticed an improvement in sound on the KEF LS50's and some of my other speakers when I've gone from 100W to 140W. I know someone is going to say it's all in your mind (placebo effect or whatever) but I've noticed a difference. Realistically the 140W (Yamaha RX-A3000) to the Salk's in my office, where I do 80% of my listening to music, is more than adequate. I just have an itch to see/hear what happens if I bump it up to 200W/350W.

 

[snakeeyes]

So if ground based hum, basically anything else 3 prong could be contributing, sounds like. (From my limited google based understanding of 2 devices on the same ground)

 

[GrimSurfer]

So if ground based hum, basically anything else 3 prong could be contributing, sounds like. (From my limited google based understanding of 2 devices on the same ground)

Or anything 2 pronged on another circuit.

There's not enough data ATT to say Dan is dealing with a ground loop. He might be, but let's wait until we have more data from him...

 

[Danzilla31]

Or anything 2 pronged on another circuit.

There's not enough data ATT to say Dan is dealing with a ground loop. He might be, but let's wait until we have more data from him...

And you'll be getting that data but Damn. I need to go work on the lawn for an hour! I'd rather be in here all day with you guys on this! I'll be back in an hour sh@$ make that an hour and a half lol with more info!

 

[GrimSurfer]

And you'll be getting that data but Damn. I need to go work on the lawn for an hour! I'd rather be in here all day with you guys on this! I'll be back in an hour sh@$ make that an hour and a half lol with more info!

All good, bro'.

Time doing other things will clear your head and allow your brain to do some background processing. All valuable things when problem solving.

 

[Danzilla31]

All good, bro'.

Time doing other things will clear your head and allow your brain to do some background processing. All valuable things when problem solving.

I know I said I would hit the yard but! I ran the frequencies and it is 60 Hz. They match exactly the sound from the speakers sounds just like the 60 Hz tone

 

[GrimSurfer]

Excellent. Using test tones to find the frequency has greatly reduced the likelihood that it is an RF problem (the noise would likely be higher in frequency).

We can now focus on the two most likely problems:

1. Ground loop, or

2. Power circuit/line induction.

Before investigating the ground loop, lets minimize induction problems (it's just good practice, regardless of whether there are audible problems or not... so this isn't going to be wasted effort).

Move your speaker wires away from any power lines/cables. Where they do have to cross, keep them at 90 degrees.

Move the speakers as far away from those Crowns as you can. Try to get the speaker wires to run as far away from the Crowns as directly as possible (straight out the back of the Crowns, not running down or along them).

Then retest. If the hum has noticeably changed, do some more fine tuning and physical separation.

Report back on the results before we go down the ground loop path... pun intended!

 

[Alex2507]

Or anything 2 pronged on another circuit.

Really? Something dirty on a different circuit can pollute you're audio?

So to be clear, the Crowns have grounded cords, right?

I went back far enough to see the grounded splitter but never got to that detail on the Crowns.

Edit: Get out of the yard already.

 

[GrimSurfer]

Really? Something dirty on a different circuit can pollute you're audio?

So to be clear, the Crowns have grounded cords, right?

I went back far enough to see the grounded splitter but never got to that detail on the Crowns.

Edit: Get out of the yard already.

Yup. Don't think of it as a dirty circuit (that would be EMI/RFI). Think of it as two circuits of different electrical potential.

When connected together, differences in electrical potential cause electrical flow. If the easiest path for that flow to take is through an amp or pre amps circuit, then this gets included in the audio signal. The result? You get hum at the same frequency as the electrical flow (which is 60 Hz in North America).

 

[Danzilla31]

Excellent. Using test tones to find the frequency has greatly reduced the likelihood that it is an RF problem (the noise would likely be higher in frequency).

We can now focus on the two most likely problems:

1. Ground loop, or

2. Power circuit/line induction.

Before investigating the ground loop, lets minimize induction problems (it's just good practice, regardless of whether there are audible problems or not... so this isn't going to be wasted effort).

Move your speaker wires away from any power lines/cables. Where they do have to cross, keep them at 90 degrees.

Move the speakers as far away from those Crowns as you can. Try to get the speaker wires to run as far away from the Crowns as quickly as possible (straight out the back of the Crowns, not running down or along them).

Then retest. If the hum has noticeably changed, do some more fine tuning and physical separation.

Report back on the results before we go down the ground loop path... pun intended!

Okay I missed your post so I went and disconnected the cable and whaa Laa

No more noise.

When I connected the coaxial back on you could literally hear it pop back into place.

 

[Danzilla31]

By popping back into place I mean the noise

 

[GrimSurfer]

Okay I missed your post so I went and disconnected the cable and whaa Laa

No more noise.

When I connected the coaxial back on you could literally hear it pop back into place.

What's the coax for? What is it connecting?

 

[Danzilla31]

Yup. Don't think of it as a dirty circuit (that would be EMI/RFI). Think of it as two circuits of different electrical potential.

When connected together, differences in electrical potential cause electrical flow. If the easiest path for that flow to take is through an amp or pre amps circuit, then this gets included in the audio signal. The result? You get hum at the same frequency as the electrical flow (which is 60 Hz in North America).

I still hear a slight hiss when I turn the gains all the way up. But! more at the tweeter and I have to stick my ear on top of it.

There is still a slight buzz at the midrange like that hum. But! Once again I have to stick my ear all the way on top of it to hear it.

 

[Danzilla31]

What's the coax for? What is it connecting?

The cable box to the cable wall

 

[Danzilla31]

Once you take it off the cable box the sound just drops

 

[GrimSurfer]

Ok. Cleaning up cable runs and repositioning the Crowns or speakers may reduce other things... but it is pretty clear that you have a ground loop.

ATT, the cable box is acting as a path for ground loop. Disconnecting the coax isn't fully resolving the problem. Differences in electrical potential between circuits still exist.. it's just taking a less bothersome path when you disconnect the cable.

You probably need that coax hook up for TV, so permanent disconnection isn't likely to be an acceptable option.

Try changing the circuit your using to feed cable box. If that doesn't work, return the cable box power feed back to its original circuit and change your AVR feed. If that doesn't work, return the AVR back to its original feed and change the Crowns' circuit. Then try changing any two of the three devices circuits.

If that doesn't work, you might need an isolation transformer... likely for your Crowns, to break the loop.

 

[Danzilla31]

What's the coax for? What is it connecting?

I still hear a buzzing coming from the woofers but not really even a hiss from my tweeters but I have to have my ear right on top of the speakers I mean literally touching it to hear that.

So there may still be an issue but its could be just a cabling rca issue like you said but if it is it's very very small almost imperceptible if I didn't have my ear right up on the speakers I'd never have noticed it and that's know with the gains turned all the way up.