Does anyone know what Ohms rating is for the HK Sub?

[trayson]

I'm pretty confident that the HK sub is a dual voice coil sub since I seem to remember that it had 4 wires going into it from the HK Amp. Does anyone know what the Ohm rating is on the sub? I would suspect it's 3 ohms or maybe 2 or 4. The factory HK speakers are 3 ohms, so I know BMW had some odd numbers...

Let me know. I sold my HK sub a while back, but am thinking about a project that would involve replacing the HK sub and retrofitting an aftermarket speaker but still using the factory HK amp. (not my vert, but a friend's).

Thanks.

Nevermind, it's 2 ohms. I took a picture back when I was selling my old HK sub and it was on the label if you zoom in!

[flyfishvt]

Interesting because the stock speakers are all 4 ohm.

[trayson]

Interesting because the stock speakers are all 4 ohm.

I don't think so. Pretty sure that they're 3 ohms... I think we have an old HK midrange lying around. I'll check.


Me thinks that you're talking out of your butt on this 4 ohm business...

I don't remember what the specs were on the Nokia speakers that come in the 10-speaker with no subwoofer system (like I had in my 328i verts that I owned).

Ebay listing for a HK speaker Pod:


Ebay listing for the 5" midrange:

[flyfishvt]

Like I said....stock are 4 ohm. I just checked a pair of kick panel speakers I pulled out of my non HK vert. I'm just curious why stock are 4 ohm and HK are different.

[trayson]

I am sure it's because the HK system has to power a sub. That sub takes up 4 channels from the amp. Lower ohm speakers are more efficient and produce more sound w/ the same power. I am not surprised. BOSE does the same kinda stuff with lower ohms...

And you said "stock". That confused me as there are 3 systems on the e36 verts. The 4 speaker lame system, the 10 speaker nokia, and the 10 speaker + sub HK system. All are stock.

[flyfishvt]

10 speaker Nokia

Good info.. thanks. Ive never been an audio guru. Verts arent exactly the best platform to try and get decent sound. At least not without a hardtop (which I just got )

[jamrobin]

So... just looking more closely at that picture because I've been thinking about pulling the HK sub out and replacing it with some Kicker 6.5 freeairs I bought as midbass fronts for another car many years ago... Almost positive based on the 2 wires in, 4 wires connected, that that puts that HK sub is 2 4 ohm voice coils in parallel (thus the 2 ohm load on the amp. If I'm right I can quite safely hook up both my 6.5s facing opposite directions and 180 degrees out of phase to give me similar to a 12 inch (...well maybe 10 they are round) All I need is to make 2 MDF baffles the same distance apart as the front and back of the HK unit without taking any more space than the HK unit itself, and without sacrificing amp efficiency...

Anyone tried this already or have insight on the available space?

[trayson]

So... just looking more closely at that picture because I've been thinking about pulling the HK sub out and replacing it with some Kicker 6.5 freeairs I bought as midbass fronts for another car many years ago... Almost positive based on the 2 wires in, 4 wires connected, that that puts that HK sub is 2 4 ohm voice coils in parallel (thus the 2 ohm load on the amp. If I'm right I can quite safely hook up both my 6.5s facing opposite directions and 180 degrees out of phase to give me similar to a 12 inch (...well maybe 10 they are round) All I need is to make 2 MDF baffles the same distance apart as the front and back of the HK unit without taking any more space than the HK unit itself, and without sacrificing amp efficiency...

Anyone tried this already or have insight on the available space?

It depends a lot on whether you have rollover protection or not. If you do NOT have rollover, it'll look like this with lots of space:





Note where the amp is:


However, if you do have rollover protection, those spots are used up with the rollover modules... I don't have a pic of what it looks like with the rollover, I guess I never took one when my M3 was getting audio love...

[jamrobin]

Thanks! That ^ is very informative! I do have the rollover protection so I'll assume less space but seeing what's behind the seat area is great. I took the rear seats out to install the wire harness for my hard top but had never seen from the trunk side.

[trayson]

Thanks! That ^ is very informative! I do have the rollover protection so I'll assume less space but seeing what's behind the seat area is great. I took the rear seats out to install the wire harness for my hard top but had never seen from the trunk side.

More pics I found online:

[PrimeGuey]

Is each voice coil 4 ohm and them the amp just wires them to 2 ohm , or are the voice coils 1 ohm each and react as a 2ohm lead?

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could just test them with an ohm meter I suppose.