Corndog
Posts: 7
Joined: Sat Mar 04, 2017 12:44 pm
Delivery Date: 04 Mar 2017

Noise after upgrading '13 SV sound system

Thu Jul 02, 2020 11:53 am

Hi all,

I recently upgraded my '13 SV w/o Bose and with Nav from its stock 'speakers' (if you can call them that). Not long after I got the car, I through in an old 200W SQ sub/amp I had laying around to help with the bottom end. However, I really wanted to improve the overall sound of the car, so I opted for a set of 4 inexpensive speakers (a pair of comps and a pair of coax) from Crutchfield to pair with another old 4 channel amp I had laying around. Speaker installation went pretty good (longest part was figuring out how to run from the x-over in the door to the new tweeters).

However, now I find that I get a noise coming through the speakers. I'd say it is ~500 Hz. It is only present when the car is in drive (it goes away when the car is in park). I suspect this is due to the frequency modulation for the AC synchronous motor. The noise also disappears when stopped at a light for a few seconds (when I assume the inverter switches off). The noise is not volume dependent.

I did the following troubleshooting:
Bypass the amp = No noise, low volume (4 ohm speakers)
Disconnect the high level input to the amp = Noise

I also scoped the +12 Vdc input (in case it was coming through there). I saw a 10 Hz waveform, but nothing new that was really visible between going from park to D. I've dialed back the gain on the amp all the way, which makes it bearable... but not the answer long term.

Anyone else have issues with noise after amplifying the speakers?

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Stanton
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Re: Noise after upgrading '13 SV sound system

Fri Jul 03, 2020 5:51 am

Corndog wrote:
Thu Jul 02, 2020 11:53 am
[edit]...to pair with another old 4 channel amp I had laying around...[edit]

I did the following troubleshooting:
Bypass the amp = No noise, low volume (4 ohm speakers)
Disconnect the high level input to the amp = Noise
I think you answered your own question...even if you don't like the answer.
You introduced an element that created hum/noise/whatever you want to call it in the system. You either return to more efficient speakers (that I guess don't sound well to you), or live with low volume and/or hum. Vehicles have many sources of hum (and ground loops), and you may never be able to "clean up" the new configuration.
2011 Blue Ocean SV w/floor mats & window tint
12v LiFePO4 battery with Antigravity Battery Tracker
FIAMM 74100 horns
Wet Okole seat covers (front)
Tor's low-power heater mod
2013 sun visor
Battery Pack replaced (Rev E) @51 months and 41k miles

Corndog
Posts: 7
Joined: Sat Mar 04, 2017 12:44 pm
Delivery Date: 04 Mar 2017

Re: Noise after upgrading '13 SV sound system

Fri Jul 03, 2020 10:02 am

Stanton wrote:
Fri Jul 03, 2020 5:51 am
Corndog wrote:
Thu Jul 02, 2020 11:53 am
[edit]...to pair with another old 4 channel amp I had laying around...[edit]

I did the following troubleshooting:
Bypass the amp = No noise, low volume (4 ohm speakers)
Disconnect the high level input to the amp = Noise
I think you answered your own question...even if you don't like the answer.
You introduced an element that created hum/noise/whatever you want to call it in the system. You either return to more efficient speakers (that I guess don't sound well to you), or live with low volume and/or hum. Vehicles have many sources of hum (and ground loops), and you may never be able to "clean up" the new configuration.
Agreed. I am hoping to hear from others that have experienced this. Looking through the forums, many members have gone about upgrading their Leaf's with speakers/amps - and not reported any ill effects.

goldbrick
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Delivery Date: 01 Aug 2017
Leaf Number: 311806
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Re: Noise after upgrading '13 SV sound system

Fri Jul 03, 2020 1:05 pm

There are lots of possible sources for electrical noise and I'm not an expert on car stereos but I would assume that there would be minimal coupling into the wires from the amp output to the speakers since it is a low impedance circuit and you're probably putting a lot of current into it to begin with. So....

my guess is that the noise is coming through the power supplied to the amp or head unit. Unfortunately, if the noise is really 500 Hz it will be hard to filter it out efficiently. You could try running (shielded) power and ground wires directly to the 12V battery. I don't think any high power part of the motor controller will be running off the 12V supply but I imagine both the high voltage motor circuits and 12V circuits are grounded to the car's chassis, so it is possible you're picking up ground noise from the high voltage circuit that is fed into the power input of the amp.

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