installed jehnerts with otherwise stock logic 7

[Lincoln30]

Originally Posted by 808M3

There are many misconceptions here, but I don't want to "make any waves".
If you are just replacing speakers, it is highly recommended that you replace them with speakers of same impedance. This is because you don't know how they are connected to each other in the car. If you are wiring your own speakers, you need to know that it makes a big difference.
There are three ways to wire multiple speakers; parallel, series and parallel-series. Each will affect the load presented to an amplifier.

Example: Lets say you are wiring together two 8 ohm speakers.
Parallel wiring: 8 ohm+ 8 ohm = 4 ohms
Series wiring: 8 ohm + 8 ohm = 16 ohms
Parallel-Series: 8 ohm + 8 ohm = 8 ohms

If you are replacing two 8 ohm speakers with 4 ohm speakers and they are wired in parallel, your impedance is now 2 ohms. Most amps will not be "happy" with this, subwoofer amps are an exception. However, if you run two 4 ohm speakers in series, then the impedance will now be 8 ohms.

Hope this helps.

I don't plan to use the stock amp and just need to know where to buy a pair of these drivers.

That said, speaker impedance rating are nominal ratings not actual. Some speakers stay very close to their rated resistance over the frequency range and others will very widely. This is likely why the stock amps work fine with some 4 ohm rated drivers and not others.

Edit: I would like to add. Anytime you go beyond what the amp is rated you will make the amp work harder and produce more heat. If the heat is dissapated fast enough you probably won't shut down the amp. I don't know how well the stock amps can do this under load for long periods of time with the bass boosted on the tone controls? So you do any of this at your own risk but some have had no issues.

[808M3]

Originally Posted by Lincoln30

I don't plan to use the stock amp and just need to know where to buy a pair of these drivers.

That said, speaker impedance rating are nominal ratings not actual. Some speakers stay very close to their rated resistance over the frequency range and others will very widely. This is likely why the stock amps work fine with some 4 ohm rated drivers and not others.

Edit: I would like to add. Anytime you go beyond what the amp is rated you will make the amp work harder and produce more heat. If the heat is dissapated fast enough you probably won't shut down the amp. I don't know how well the stock amps can do this under load for long periods of time with the bass boosted on the tone controls? So you do any of this at your own risk but some have had no issues.

If you plan on using an aftermarket amp, check its specs or talk with dealer selling. Most will give you power specs at 8 ohms and 4 ohms. Unless its a dedicated amp, I have never heard of an amp that cannot run either 8 ohm or 4 ohm "rated" speakers. Yes, there is an "ideal" resistance, but its not an absolute one. (Ohms is resistance, how difficult it is for an electrical current to "flow". 4 Ohms offers less resistance than 8 ohms. You will find that many amps produce more power at 4 ohms than at 8 ohms).
Overheating amps is not as simple as you have stated, there are many reasons. Most home audio amps, have fans or heat sinks to cool it, most car amps do not. Therefore, car amps need to be located where cool air can circulate around it, not in an enclosed space. Compatibility. If your amp is underpowered, you have to run it close to its max rating, which may cause it to overheat. If your amp has safety "features", it will shut down. If your amp "clips" it may destroy your speakers (no matter what your speakers are rated at.) On the other side, if you overpower your speakers, you will destroy them. It is advisable to put a fuse on the speakers.
Talk to an expert as to what your needs are. What is important is how loud you like your music. They will match an amp specs with your speakers spec..

[8600RPM]

Pounding these jehnerts hard daiky at nearly max volume (80 percent of max), and no issue whatsover. It's been months of daiky hard use. With jehnerts I leave bass in center vs oem I had it plus,2 and still never got decent thump.

[Curamrda]

Hi,

I have Individual audio in my E92 from stock..

I had in my previous e92 upgraded the HIFI to JL Audio 600 + strong speaker set.... so now, I am not really happy with the Individual audio.
I can recognize, that mids and tweeters are fine..but the Individual subs suck...I was all the time thinking about the upgrade the SUBs..but was afraid of the Ohms. So you are telling me, its proven, that Jenherts will do fine with the OEM individual AMP ??

//edit: now I see why . In SPEC they are 6ohms, in reality ccas 6,5ohms that should be fine i guess
https://www.e90post.com/forums/showp...17&postcount=8
https://www.jehnert.de/en/shop/speak...t-housing-bmw/

I would like to try MB Quart subwoofers, but I am afraid, that I will damage the AMP, since they are 4ohms... :/
Can anybody confirm, that its safe to use 4ohms SUBs with OEM Individual AMP?