[sarav100]

I recently got audio setup upgraded from factory speakers to aftermarket while still using factory fitted Hyundai Creta 8 inch touchscreen.

Installs done:
1. DB Drive Euphoria ES3 Components (front doors)
2. DB Drive Euphoria ES3 Coaxials (rear doors)
3. Kenwood 1000w 4 channel amplifier to power the above component and coaxial speakers
4. Rockford Fosgate R1 subwoofer in relatively slim enclosure to complement the above speakers
5. GVAA (some unknown brand but installed since I don't prefer heavy subwoofer bass) 2 channel amplifier to drive subwoofer
6. Brazo 4 gauge wiring kit for Kenwood 4 channel amplifier (relatively heavy wiring)
7. Chicago 8 gauge wiring kit for 2 channel subwoofer amplifier (relatively normal/light wiring)
8. JBL high low converter for stock HU to RCA conversion
9. Plastic insulation for all wiring kit power cables
10. CTK standard double layer damping on 4 doors

I'm satisfied with the sound quality of speakers and subwoofer is more than enough for my taste and installer did pay a lot of heed to install everything with proper insulation.

Now, the problem is that there is a very slight alternator whine(turbo whistling kind of sound) in the system. It is very minute but petrol Creta has excellent NVH to begin with and once I hit cruising speeds on highway and if music is off, I can hear that slight whine and nothing else due to the fact that car is silent otherwise.

I contacted my installer over phone and he asked to check if it is from front tweeters and yes, it was from tweeters alone. He mentioned there are only 2 ways to go about it:

1. Install noise insulator but at the cost of audio quality. As per him noise insulator will lead to loss of audio quality, beating the purpose of doing aftermarket audio upgrade in the first place.
2. Just live with it if it doesn't bother much. He suggests this approach as whine is anyways very minor and I prefer audio quality.

So, folks, I'd like to know if there's a 3rd approach as well apart from the two mentioned above ?

Please note that the ground loop fix that is usually used to ground RCA connectors with HU might not work here because stock HU has no RCA and JBL RCA converter has plastic body.

[a4anurag]

Originally Posted by sarav100

I contacted my installer over phone and he asked to check if it is from front tweeters and yes, it was from tweeters alone.

Looking at the setup and components used I can think of one or two reasons for this whine.

1. Gains may be set slightly on the higher side inducing the whine through the tweeters ONLY. Reduce the gain and see if it helps.
   
   
2. Can you share an image of ground for the two amplifiers that have been used?

[straight6]

Check if they have installed the rca's on the same side as the power and ground cables. This can also be the reason. They should not be running next to each other.

[sarav100]

Originally Posted by a4anurag

Looking at the setup and components used I can think of one or two reasons for this whine.

1. Gains may be set slightly on the higher side inducing the whine through the tweeters ONLY. Reduce the gain and see if it helps.
   
   
2. Can you share an image of ground for the two amplifiers that have been used?

Hi a4anurag,

Thanks for the suggestion and apologies for the late reply.

Here are the updates of findings:

Gain Settings:

Since gain settings were easy to access, I tried adjusting them first. On adjusting the gains I understood that Kenwood amplifier's Channel A is connected to front component mid range speakers while Channel B is connected to front component tweeters and rear coaxial speakers. On adjusting the gain setting on Channel A as well as Channel B, I was able to eliminate the whine 100% but at that setting, the volume output was reduced by good margin. Hence, adjusting gains does not yield the desired results without loss of output.

On the positive side, I really understood the way mid range and high frequency range sound is amplified and adjusted it to my taste instead of keeping the setting that installer had set as per his preference. Now, I need to invest in boot damping as well to match the adjusted mid range output.




Earthing Connection:

I was sceptical regarding opening side panel to access earthing connection, so I waited for a visit to installer, which happened last week only. I'm attaching the pictures of the same and by looking at them, I couldn't see anything wrong. All power and earthing cables have been insulated from each other using additional layer of insulation tube throughout the car(insulation visible in the pictures). Please let me know if you see any red flags with regards to the same.




Amplifier switch:

When the whine did not reduce via gain settings and earthing was also looking fine, I decided to install a switch to turn off the amplifier when it is not in use. The switch was installed connected to Remote terminal of amplifier. Pictures of installation attached for reference.




Hi @straight6,

If I'm not mistaken, power cables have been installed on both sides of car while all RCA cables are laid in the central gearbox tunnel. Also, the power and ground cables are shielded from each other on each side with additional plastic tubing. So, I'm not sure if they would interfere with sound output. You may refer to the above pictures for details.

[nura]

Originally Posted by sarav100

Thanks for the suggestion and apologies for the late reply.
....

Could you solve the noise problem? Crutchfield has a very use useful flowchart on its website for diagnosing noise issues.

[sarav100]

Originally Posted by nura

Could you solve the noise problem? Crutchfield has a very use useful flowchart on its website for diagnosing noise issues.

Nope, I didn’t put efforts into removing noise since I got switch installed and I just turn off amplifier when it is not in use. However, if you could please share the flow chart link, I will look into solving it for my learning and future use.

[a4anurag]

Originally Posted by sarav100

I couldn't see anything wrong. All power and earthing cables have been insulated from each other using an additional layer of insulation tube throughout the car (insulation visible in the pictures). Please let me know if you see any red flags with regards to the same.

I am not really sure if that is a good grounding point. That metal frame is on a painted surface. You need a bare metal for a good grounding to happen and avoid any ground loop issues that is troubling you.

I presume this is the new Creta, there is one common factory grounding point near the left/right footwell behind the trim panel (just above the hood release handle). Trying to use that as a ground point for the connection.

[nura]

Originally Posted by sarav100

Nope, I didn’t put efforts into removing noise

https://images.crutchfieldonline.com...seSuppress.pdf

[sarav100]

Originally Posted by a4anurag

I am not really sure if that is a good grounding point. That metal frame is on a painted surface. You need a bare metal for a good grounding to happen and avoid any ground loop issues that is troubling you.

I presume this is the new Creta, there is one common factory grounding point near the left/right footwell behind the trim panel (just above the hood release handle). Trying to use that as a ground point for the connection.

This ground wire is connected on the left passenger side footwell trim. Hood release lever is on the right driver side footwell. I’m presuming right side grounding point is being used by the subwoofer amplifier grounding using 8GA wiring. No noise persists on the subwoofer though, maybe because it can operate only on lower frequencies or maybe because it is grounded properly as you said.

Also, the crutchfield link shared by above BHPian asks to connect grounding to an independent point, not shared by any other electronics. What are your thoughts on this ?

[a4anurag]

Where is the amplifier installed? Underseat?

I feel it is best to use a metal wire brush, strip some paint, and then put the ground connection using a ring terminal. That shall be the best possible ground connection.

Originally Posted by sarav100

This ground wire is connected on the left passenger side footwell trim. Hood release lever is on the right driver side footwell. I’m presuming right side grounding point is being used by the subwoofer amplifier grounding using 8GA wiring. No noise persists on the subwoofer though, maybe because it can operate only on lower frequencies or maybe because it is grounded properly as you said.

So you have 2 ground wires and 2 power wires - one set for the speaker amplifier and the other set for the subwoofer amplifier. Right?

[nura]

Originally Posted by sarav100

Also, the crutchfield link shared by above BHPian asks to connect grounding to an independent point, not shared by any other electronics. What are your thoughts on this ?

Here Crutchfield is talking about the grounding point for the head unit.
It's perfectly alright to ground multiple amplifiers and a DSP, if present, to the same grounding point.
When using multiple amplifiers it may be convenient to use a fused power distribution block and an UNFUSED ground distribution block.

[sarav100]

Originally Posted by a4anurag

Where is the amplifier installed? Underseat?

Yes, Kenwood amplifier is under passenger seat that powers tweeters, mid range components and rear coaxials. It uses 4GA wiring kit.

Generic GVAA amplifier is under driver seat and drives the subwoofer. It uses 8GA wiring kit.

Originally Posted by a4anurag

I feel it is best to use a metal wire brush, strip some paint, and then put the ground connection using a ring terminal. That shall be the best possible ground connection.



So you have 2 ground wires and 2 power wires - one set for the speaker amplifier and the other set for the subwoofer amplifier. Right?

Yes, wire brush method is the best method but I’m wary of unwanted consequences like rust in future.


I have 2 powers wires with 2 separate fuses powering each amplifier. However, I’m presuming there should be 2 ground wires with 2 different grounding points but I’m not sure about it.

Some pics of power wires and fuses for reference.

[nura]

Originally Posted by sarav100

Yes, wire brush method is the best method but I’m wary of unwanted consequences like rust in future.

Application of dielectric grease after paint removal will prevent corrosion while maintaining electrical continuity.

[sarav100]

Hello BHPians,

I went ahead with installation of S&B Amplifier with in built equaliser for balancing the sound of all songs as previous amplifiers had only gain control. It alone is able to drive components, coaxials and subwoofer and equaliser has balanced most of the instruments being played. Although I have no idea about it’s output levels since it came without specifications but on hearing there’s at least 60-70% real improvement over the previous amplification setup.

As an added bonus, the new amplifier eliminated the whine and the sound output is devoid of any abnormalities. No change was made to the 4AWG wiring or its terminals.

Thank you all for your inputs.