Issue with Bavsound subs on HK E93

[Mr.Zisky]

Hi all!

I purchased "Bavsound Ghost BMW Underseat Subwoofers V3" for my European (I'm mentioning since apparently there are some slight differences between US and EU cars when it comes to audio) E93 with Harman Kardon system (S688). After installation I immediately heard the difference. The difference was that I lost bass almost completely tho the point that I first I thought they are not working, but I double checked the connectors and well, when playing music the subs membrane does move so they do "work". They are however, waaaay quiter than OEM subs and if seems like they only work in a very narrow frequency so for 90% of the time it feels like they don't work at all and 10% of the time I can hear some bass but it's still quiter than OEM. I contacted Bavsound but they were useless. They send me a standard message saying "check connectors, check your audio source, etc, etc". I started googling and almost every source I found says that E9x Harman Kardon system has 4 Ohms subwoofers (and it's the Individual Audio that takes 8 Ohms). So I measured the OEM woofers that I took of my car with multimeter and they show 2.7 - 3.0 Ohms which sort of confirms that? Not sure why they don't show closer to 4 Ohms but I'm not expert in electronics. I contacted Bavsound again with my findings but they just replied "you're wrong. HK takes 8 Ohms"

So, my question is. Can anyone conifrm/deny if HK subs in E9x (I've read that F8x HK system does indeed have 8 Ohms subs) are 4 Ohms?

[sergbaja5t]

I do believe they are 4ohm. I bypassed the factory sub channels all together and added a separate amplifier to power the subs. Its a difference of night and day.

[nrubenstein]

That's about right for a 4 ohm speaker. Speakers aren't the same impedance at all current flows.

Note that a 4 ohm speaker will be LOUDER than the 8 ohm speaker at the same power level.

In the US, there was only Hifi or Individual.

[Mr.Zisky]

Originally Posted by nrubenstein

Note that a 4 ohm speaker will be LOUDER than the 8 ohm speaker at the same power level.

Yeah. Bavsounds are way quieter than OEM so that make sense. I really don't understand how a company that only sells speakers can get this wrong ;/