Subwoofer Hum

[ChristopherFinlay]

Recently installed a Pioneer under-seat subwoofer to my 2019 Seat Leon. I spliced into both rear speakers using a harness extension and used a speaker wire to RCA converter. All seem to be going well until I started my car and I could hear the RPMs through the sub. It actually sounded like I had a blow out in my exhaust. Everything seems to be grounded properly.

The only solution I’ve found is having the gain turned right down. Any suggestions welcome

Many thanks.


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[TripleBob]

Do you still have the soundaktor (fake engine noise module) active?
You might also be picking up noise from the RCA adapter

 

[Tell]

Well if it was a home surround sound system you'd look at earthing.... that's the pest of active subs interference getting into the cable. You got something leaking into that cable, obviously is your issue. I'd call up @East Yorkshire Retrofits, but they would probably say you should have used their services. Basically, I don't reckon you can post fit subwoofers to existing systems by tapping into the existing speaker outlet, although people do and kits are sold to do it.

The crossovers are electronic these days, so each of the speakers gets it's own feed. Tapping into the existing speakers is taking a frequency slice that's going out to it which could already been trimmed, and you'd want that mixed out... well I do remember going to Notting Hill weekend once, but I'll pass on recreating that in the car.

So you might be getting some signal modulated into the connection like the mobile phone, the infotainment unit or whatever. Databus is Ethernet I recall was talk of optical, so there is a lot going on in the car. Probably the quality of the cable and screening, in the connection, pulling other stuff (the interference) or it's found an "earth".

 

[East Yorkshire Retrofits]

Recently installed a Pioneer under-seat subwoofer to my 2019 Seat Leon. I spliced into both rear speakers using a harness extension and used a speaker wire to RCA converter. All seem to be going well until I started my car and I could hear the RPMs through the sub. It actually sounded like I had a blow out in my exhaust. Everything seems to be grounded properly.

The only solution I’ve found is having the gain turned right down. Any suggestions welcome

Many thanks.


Sent from my iPhone using Tapatalk

Try a different hi-lo converter. Where’s it connected for power/ground?

Seat Sound would’ve been more straight forward and offered an all round upgrade

 

[ChristopherFinlay]

Try a different hi-lo converter. Where’s it connected for power/ground?

Seat Sound would’ve been more straight forward and offered an all round upgrade

I would have loved to use your services unfortunately being based in Northern Ireland those possibilities aren’t available “ I see your work it’s top class”. I personally think the high low conversion is the issue as it was a cheep Halfords one.

Have you any recommendations for decent high low conversion?

Regarding my grounding question the rca high low conversion is grounded to chassis same as the sub


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[TripleBob]

You could have ordered a self install kit from Kieran (could still be an option if you can’t fix the feedback?) and then either shipped him your mib unit or self coded the parameters

In my previous car I did a full Focal speaker install with Pioneer double din CarPlay head unit - and used a Focal HILO v3 with great results. Not sure if you can still get them, but it was shielded which will probably help with whatever interference you’re picking up?

 

[ViperSlider]

When using this kind of set up, the most critical place to spend the money is the Hi-Low converter. The cheap ones will always give poor results in one way or another. JL Audio and AudioControl are 2 brands that come to mind that make great converters.

I'd revisit your ground too, just to ensure that is secured correctly and has a good metal contact.

 

[SuperV8]

I would have loved to use your services unfortunately being based in Northern Ireland those possibilities aren’t available “ I see your work it’s top class”. I personally think the high low conversion is the issue as it was a cheep Halfords one.

Have you any recommendations for decent high low conversion?

Regarding my grounding question the rca high low conversion is grounded to chassis same as the sub


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This is quite interesting regarding speaker to rca converters;

What Is A Line Output Converter? The Definitive Guide

Not sure what a line output converter is and why you need it for your car audio system? This guide explains it all with great diagrams and clear information.

soundcertified.com

 

[Tell]

You could have ordered a self install kit from Kieran (could still be an option if you can’t fix the feedback?) and then either shipped him your mib unit or self coded the parameters

In my previous car I did a full Focal speaker install with Pioneer double din CarPlay head unit - and used a Focal HILO v3 with great results. Not sure if you can still get them, but it was shielded which will probably help with whatever interference you’re picking up?

The @East Yorkshire Retrofits are self install as well.

 

[TripleBob]

The @East Yorkshire Retrofits are self install as well.

That is Kieran!

 

[Tell]

We have to be careful that we don't promote non sponsors ... else Kieran complains ... and I delete the offending post. It is a little hot bed of Mib activity up in Yorkshire... so we are all good .

Mines a factory fitted Seat sound system like he's selling as an addon. Works fine.... no low frequency buzz.

Shielding yes and earthing if it's like a home surround system with an active sub woofer. The 50mhz mains hum get into home systems and being the sub woofer you hear it. 13amp cable strips to avoid, the sub woofer unit plugged straight into the wall to isolate that from the rest. Modern car will have a lot of telematic noise going on in them.

Any low frequency signal if it leaks into the system gets boosted up so you hear it. Worse still are any loose connections which have to be rock solid else you end up hearing the loose connection with a build in feedback loop and a very loud buzz. Pity my neighbours when a bus went outside causing in the middle of the night... it happened a more than ince... a cat fight on the carpet over the connection had created a loose connection unbeknown to me. Got up in the night to stop it. Best to splash the cash on quality cables and not solder joints yourself. You hear a dry joint least on home systems. Been there done that. All coaxial commercial built cables on the sub now.

Suspects it's a poor sub amp in the car being open to generated noise, earthing or the deadly loose connection that vibrates in time to the sub. That one is the curse of home systems with poor cables.