Static!

[alcoprop]

So I just fired up my new system. I had horrible static last year and decided to upgrade a few things this year to try and get rid of it. I added batteries, fixed and shortened battery cables (they were like 6’ too long) added on board chargers, and added an Audio Control DM810. My amps are all wetsounds and only a year old. The static is still there and probably worst. Boat is on the trailer and motor off. The static gets louder with volume and gets louder the higher the gains are on the amps. When I first found I have static still I started unplugging everything. The static is still there with no rca cables plugged into anything and just the head unit and amps are on. When I plug the rca in with head unit on it makes a real loud static sound. When I turn the battery switch off the static gets louder. I have checked grounds and everything. Highly doubt this could be an amp issue could it? All 3 of them are doing it. Thoughts? 

Edited April 21, 2022 by alcoprop

[MLA]

3 minutes ago, alcoprop said:

The static is still there and probably worst.

Adding a line driver will do this, is it amplifies whats already there. 

4 minutes ago, alcoprop said:

The static is still there with no rca cables plugged into anything

However, with no signal cables connected to an amp, and unwanted noise is still there points to the noise coming in at the amp level. Now, dont read what im not typing. Im not saying the amp is bad and producing the noise. This simply eliminates the signal path upstream. Excessive gain is the first that comes to mind. Are there RGB LEDs in there and are they on? If so, turn them off. 

9 minutes ago, alcoprop said:

When I turn the battery switch off the static gets louder

This makes me scratch my head. Turn the battery switch off, the amps should turn off and likely with a thump or pop. 

11 minutes ago, alcoprop said:

All 3 of them are doing it.

3 bad amps all doing the same thing at the same time would be a crazy coincidence. 

[alcoprop]

12 minutes ago, MLA said:

Adding a line driver will do this, is it amplifies whats already there. 

However, with no signal cables connected to an amp, and unwanted noise is still there points to the noise coming in at the amp level. Now, dont read what im not typing. Im not saying the amp is bad and producing the noise. This simply eliminates the signal path upstream. Excessive gain is the first that comes to mind. Are there RGB LEDs in there and are they on? If so, turn them off. 

This makes me scratch my head. Turn the battery switch off, the amps should turn off and likely with a thump or pop. 

3 bad amps all doing the same thing at the same time would be a crazy coincidence. 

No RGBs at all. Just removed my ground at the engine block and reinstalled no change. The music sounds great while turned up to loud listening volume but man when the song ends and another one starts the static is loud! Sounds horrible  

 

[alcoprop]

I bypassed the DM810 and it is a million times better. More like I remember it last year. The DM810 amplifies the white noise by like 1000%. 

[shawndoggy]

27 minutes ago, alcoprop said:

I bypassed the DM810 and it is a million times better. More like I remember it last year. The DM810 amplifies the white noise by like 1000%. 

how do you have the input gain set up out of the dm810?  Have you tried turning that down?

This video is pretty good for how to use the audiocontrol dsp software (on an amp with DSP built in, but principles should be the same)

 

[alcoprop]

Just now, shawndoggy said:

how do you have the input gain set up out of the dm810?  Have you tried turning that down?

This video is pretty good for how to use the audiocontrol dsp software (on an amp with DSP built in, but principles should be the same)

 

So I will be the first to admit that I am new with the DSP tuning. But yes if I turn the input gain all the way down the amplified white noise is gone. But of course The volume is effected by this and it is no where near loud enough. Same thing in the amps, if I turn the gain all the way down that helps tremendously. 

[shawndoggy]

1 minute ago, alcoprop said:

So I will be the first to admit that I am new with the DSP tuning. But yes if I turn the input gain all the way down the amplified white noise is gone. But of course The volume is effected by this and it is no where near loud enough. Same thing in the amps, if I turn the gain all the way down that helps tremendously. 

its probably going to be a mix of the two (amp gains / dsp input gain / dsp output levels) to find the acceptable noise floor.  The DSP 810 can put out 10v, which is surely way more voltage than you want or need, and probably at least double the factory outputs.  ( @Slurpee did you measure factory HU output voltage on your install?)

[alcoprop]

4 minutes ago, shawndoggy said:

its probably going to be a mix of the two (amp gains / dsp input gain / dsp output levels) to find the acceptable noise floor.  The DSP 810 can put out 10v, which is surely way more voltage than you want or need, and probably at least double the factory outputs.  ( @Slurpee did you measure factory HU output voltage on your install?)

The white noise is still there with the 810 bypassed just no where near the level it is with it hooked up. That’s what is annoying to me mostly. I feel like if I got rid of what is causing the white noise then the 810 would be good. It’s frustrating! 

[shawndoggy]

13 minutes ago, alcoprop said:

So I will be the first to admit that I am new with the DSP tuning. But yes if I turn the input gain all the way down the amplified white noise is gone. But of course The volume is effected by this and it is no where near loud enough. Same thing in the amps, if I turn the gain all the way down that helps tremendously. 

is your battery charger plugged in while you are doing this test?

[alcoprop]

4 minutes ago, shawndoggy said:

is your battery charger plugged in while you are doing this test?

It was at first but I thought about it and unhooked it and there was no change 

[Slurpee]

Oh boy. I’d love to help. Just swing on down to Granbury with some steaks and lively conversation. 

[alcoprop]

1 minute ago, Slurpee said:

Oh boy. I’d love to help. Just swing on down to Granbury with some steaks and lively conversation. 

I wish I could! 

[Slurpee]

3 hours ago, shawndoggy said:

its probably going to be a mix of the two (amp gains / dsp input gain / dsp output levels) to find the acceptable noise floor.  The DSP 810 can put out 10v, which is surely way more voltage than you want or need, and probably at least double the factory outputs.  ( @Slurpee did you measure factory HU output voltage on your install?)

Yes I did. Outputs to my Amps from my 2016 head unit were as follows from my notes. Spoiler: The worst SNR is hard wired from the phones headphone port into the aux input. But honestly what do you expect from a tiny phone meant to drive ear pods. Even a big MacBook doesn’t bump the signal levels that much. Also, these levels are very close to what I got from my 2019 through the factory unit before I bypassed it. They’re also close to the newer units I’ve helped debug.

************

Running Bluetooth I’m going to measure the pre-amp input at 1kHz from my iPhone at 1-click from max (BT module distorts at full).  It’s 1.3Vpp until about 10kHz and then rolls off to 1.17Vpp at 16kHz and it’s so annoying. I’ll fix my own sound thank you.

Running Aux in from iPhone to measure the pre-amp input at 1kHz at full volume (no distortion from phone itself).  It 0.536Vpp across the input spectrum. Nice clear signal here. Better than BLE but the signal is so small. System noise is too high and there is humming and hissing at higher amp gains.

Running Aux in from MacBook Pro to measure the pre-amp input at 1kHz at full volume (-3dBFS on REW with no distortion).  It is 0.712Vpp across the input spectrum.  This is good enough that when I set the amp gains I have a tolerably small amount of speaker hiss and hum

*********

I don’t know if that helps but at least it gives a datapoint for future readers.  

Edited April 22, 2022 by Slurpee

[Ken10]

Know body has mentioned the depth finder yet it will cause noise interference through the proximity of all involved cabling good luck!

 

[alcoprop]

8 hours ago, Slurpee said:

Yes I did. Outputs to my Amps from my 2016 head unit were as follows from my notes. Spoiler: The worst SNR is hard wired from the phones headphone port into the aux input. But honestly what do you expect from a tiny phone meant to drive ear pods. Even a big MacBook doesn’t bump the signal levels that much. Also, these levels are very close to what I got from my 2019 through the factory unit before I bypassed it. They’re also close to the newer units I’ve helped debug.

************

Running Bluetooth I’m going to measure the pre-amp input at 1kHz from my iPhone at 1-click from max (BT module distorts at full).  It’s 1.3Vpp until about 10kHz and then rolls off to 1.17Vpp at 16kHz and it’s so annoying. I’ll fix my own sound thank you.

Running Aux in from iPhone to measure the pre-amp input at 1kHz at full volume (no distortion from phone itself).  It 0.536Vpp across the input spectrum. Nice clear signal here. Better than BLE but the signal is so small. System noise is too high and there is humming and hissing at higher amp gains.

Running Aux in from MacBook Pro to measure the pre-amp input at 1kHz at full volume (-3dBFS on REW with no distortion).  It is 0.712Vpp across the input spectrum.  This is good enough that when I set the amp gains I have a tolerably small amount of speaker hiss and hum

*********

I don’t know if that helps but at least it gives a datapoint for future readers.  

What is weird with my situation is I have white noise with no RCAs plugged in to anything. Just boat power on, dash power/radio on and amps are on with speaker wire plugged in. I can put my ear up to the speaker and hear white noise. This might be acceptable for these boats but who knows. For sure when I plug in RCAs and run through the DSP it is significantly worse especially when I try to set gains. 
 

I thought about bypassing the factory unit also. 

[Slurpee]

Ronnie’s boat did that once. We traced it to the Sport Dash Knob and electronics believe it or not. 

You shouldn’t have that hum. 

It can be anything from loose power cables anywhere in the boat to interference from the electronics. 

I suppose all that’s left is unplugging things one by one until you find a culprit. The depth gauge is a good example. Just anything under the dash really. 

[justgary]

2 hours ago, alcoprop said:

no RCAs plugged in to anything

 

2 hours ago, alcoprop said:

hear white noise

Is the noise actually white noise, or something else?  White noise should have a "sh" sound.  Please post a short video of your noise.

Make some RCA shorting plugs (anything lower than about 100 Ohms resistance from pin to shield) and insert them into all RCA inputs and try again.  Noise still there with the gain turned up?  If it is gone, add one input and leave the rest of the shorting plugs and try again.

 

[alcoprop]

1 hour ago, Slurpee said:

Ronnie’s boat did that once. We traced it to the Sport Dash Knob and electronics believe it or not. 

You shouldn’t have that hum. 

It can be anything from loose power cables anywhere in the boat to interference from the electronics. 

I suppose all that’s left is unplugging things one by one until you find a culprit. The depth gauge is a good example. Just anything under the dash really. 

So I just found a loose ground under the dash. Fixed that no change. So I then ran a 12v constant to the remote turn on and hooked the batteries up directly to the batteries to bypass the boat completely and I still have white noise static. I highly doubt that it is an amp issue since all 3 of them are doing it. So ground issue? 

[alcoprop]

15 minutes ago, justgary said:

 

Is the noise actually white noise, or something else?  White noise should have a "sh" sound.  Please post a short video of your noise.

Make some RCA shorting plugs (anything lower than about 100 Ohms resistance from pin to shield) and insert them into all RCA inputs and try again.  Noise still there with the gain turned up?  If it is gone, add one input and leave the rest of the shorting plugs and try again.

 

Read above post. 

[Stevo]

How is everything grounded? Based on the installation everything looks clean and that this isn’t your first time around the block.

I would probably go back to square 1 and start 1 amp at a time using an older form of media input like iPod to RCA cable, and see if you can get a clear signal, then slowly add components.

 

[Slurpee]

7 minutes ago, alcoprop said:

So I just found a loose ground under the dash. Fixed that no change. So I then ran a 12v constant to the remote turn on and hooked the batteries up directly to the batteries to bypass the boat completely and I still have white noise static. I highly doubt that it is an amp issue since all 3 of them are doing it. So ground issue? 

12V to an amp direct from the battery and nothing else on the wire?  Terminals to amp board and back.  No perko, nothing?

Okay, keep getting simpler.  Disconnect power to all but one amp.  That 810 is going to let you set your signal levels when you put it back in the chain.  If you fit those signal levels into the input window allowed by the amp, then you really don't need the gain hardly turned up at all for best power on the amp in my experience.  Maybe 25% for starters.

Do you still have noise with no preamp connections, a dedicated power link to the battery, and gain at 25%?  Add the other amps back in one at a time.  Same thing.  Then add back in the perko.  Keep going.

Do this and then we'll talk about how to put your DSP back in the loop and at least get the gains about right to see what's going on.

 

[alcoprop]

41 minutes ago, Slurpee said:

12V to an amp direct from the battery and nothing else on the wire?  Terminals to amp board and back.  No perko, nothing?

Okay, keep getting simpler.  Disconnect power to all but one amp.  That 810 is going to let you set your signal levels when you put it back in the chain.  If you fit those signal levels into the input window allowed by the amp, then you really don't need the gain hardly turned up at all for best power on the amp in my experience.  Maybe 25% for starters.

Do you still have noise with no preamp connections, a dedicated power link to the battery, and gain at 25%?  Add the other amps back in one at a time.  Same thing.  Then add back in the perko.  Keep going.

Do this and then we'll talk about how to put your DSP back in the loop and at least get the gains about right to see what's going on.

 

12v and remote turn on straight to battery only thing in between is the fuse block. No RCAs hooked up to the amp just power ground and speaker wire and still have the same static. Only one amp hooked up. 

Edited April 22, 2022 by alcoprop

[Stevo]

Any chance you have another amp?

hard to believe all 3 are bad, but they are starting to be the only common denominator 

[Slurpee]

Where do you have the amp gain set at on a scale of 1 to 10?

[alcoprop]

18 minutes ago, Stevo said:

Any chance you have another amp?

hard to believe all 3 are bad, but they are starting to be the only common denominator 

I do and I will see if that amp does it. I did talk to wetsounds and they want to warranty all 3 amps.