[M2withACC]

Hi guys!

I have a 2017 M2 with HK. Currently the stock amp is pushing the mids and the tweeters. Focal amp to push the woofers. ASD is coded to mute. Am I doing this correctly? Should I get an aftermarket amp to push mids and tweeters to achieve better sound quality?! M2 is so confusing to install, F80 M3 HK is way easier. I should have bought Technic's harness to save all the troubles.

Focal 100KRS 4
Focal IFBMW-SUB 8
Focal Impluse 4.320

https://www.focal.com/en/car-audio/c...s/impulse-4320

Thanks for any inputs!

[Viffermike]

Originally Posted by europeankar

Hi guys!

I have a 2017 M2 with HK. Currently the stock amp is pushing the mids and the tweeters. Focal amp to push the woofers. ASD is coded to mute. Am I doing this correctly? Should I get an aftermarket amp to push mids and tweeters to achieve better sound quality?! M2 is so confusing to install, F80 M3 HK is way easier. I should have bought Technic's harness to save all the troubles.

Focal 100KRS 4
Focal IFBMW-SUB 8
Focal Impluse 4.320

https://www.focal.com/en/car-audio/c...s/impulse-4320

Thanks for any inputs!

First, a few questions:
- Where is the Focal amp in the signal chain if it is only driving the subs? I ask because the HU does not output bass-only frequencies; only 2.0 stereo front L/R and rear L/R channels. If you're driving an already amplified speaker-level signal, that's far from ideal and can potentially damage those underseat drivers.
- I assume your 100 KRS set is in the front. What are you running in the rear? Another 100 KRS set?

Your easiest path is going to be to add a four-channel amp to drive the KRS set(s), or -- and this is what I would do -- remove and sell the Impulse and replace it with a six-channel amp such as a Focal 6.900.

[M2withACC]

Hi,
My installer couldn’t find a better way to install the amp so He spliced the HK amp wires and I am using the front L/R channels. Yes, 100 KRS on the doors, HK center and rear. Now, if I adjust the sound to the rear I get no bass! My installer said the factory systems are the same?!

The gain on the amp is very minimal. There is like no way He could get any signals so He tried the rear L/R signal first and it sounded weird and the front L/F sounds the way it should. I hope I won’t fry anything.

[BEM-S4]

See now you should have done some research first. The add a sub harness is an easy option for what you're looking at. Read up a little before going further with current path.

[Viffermike]

Originally Posted by europeankar

Hi,
My installer couldn’t find a better way to install the amp so He spliced the HK amp wires and I am using the front L/R channels. Yes, 100 KRS on the doors, HK center and rear. Now, if I adjust the sound to the rear I get no bass! My installer said the factory systems are the same?!

The gain on the amp is very minimal. There is like no way He could get any signals so He tried the rear L/R signal first and it sounded weird and the front L/F sounds the way it should. I hope I won’t fry anything.

Yes: As BEM-S4 says, read some of the other megathreads in this subforum.

Before you do anything, consider:
- Disconnecting the center channel speaker entirely (It does NOT function as a true surround center channel; it merely sums the front stereo signal and muddies up the soundstage)
- Upgrading the rear speakers to Focal coaxials (at a minimum) or another set of KRS 100s

The problem with how your installer dealt with the underseat subs is that he spliced into the front-channel line-level output wiring to get them a signal. The reason you have no bass when you fade to the rears is because the subs no longer receive a rear-channel signal from the HK amp. The subs run off of a summed signal from all four output channels, so that they operate in stereo yet also automatically fade (but don't disappear) in output as you adjust the fader from center. The fix for this? A proper six-channel amp (or a stereo amp with four inputs, which is rare) or that sub harness BEM-S4 mentions.

[M2withACC]

Originally Posted by BEM-S4

See now you should have done some research first. The add a sub harness is an easy option for what you're looking at. Read up a little before going further with current path.

Yeah I really want to buy the harness but I can’t reach Technic during holidays.

[M2withACC]

Originally Posted by Viffermike

Yes: As BEM-S4 says, read some of the is rare) or that sub harness BEM-S4 mentions.

Thanks for the awesome reply! I am thinking to get a better set of focals front mids and tweeters and I will move 100KRS to the rear. Will this be okay for the amp?! 4 channels but 2 speakers got lower wattage. I want to buy the Technic’s harness very badly. When I open my door now. I can hear this pop from my mid/high. Extremely annoying. Installer said when he removed x-overs then it is okay. I think this is all messed up.

I need to get Technic’s harness asap then I will let the installer restore back to stock then I guess it’s simply plug and play. What’s causing the poping noise? Thanks a lot!! Merry Xmas!!

focal es100k ( front ) thinking to buy this
focal 100krs 4 ( rear )
focal ifbmw-sub 8 ( under )
6 channel amp? ( trunk )
What should I do with my current amp? ( trunk )

[M2withACC]

Originally Posted by Viffermike

Y A proper six-channel amp (or a stereo amp with four inputs, which is rare) or th.

I just sat in my car and without the ignition, I can hear the static/noise from the 4" and 1". This is definitely abnormal. I have an Alpine PDX F4 sitting around which has four inputs. Should I just get the harness either replace the whole amp or add a sub harness? I want a clean setup. Thank you Mike!!

[Viffermike]

Originally Posted by europeankar

I just sat in my car and without the ignition, I can hear the static/noise from the 4" and 1". This is definitely abnormal. I have an Alpine PDX F4 sitting around which has four inputs. Should I just get the harness either replace the whole amp or add a sub harness? I want a clean setup. Thank you Mike!!

I would use the PDX F4 to drive the Focals front and rear, and get a second PDX F4 and bridge it to run in 2-channel mode to drive the underseat subs.

The great things about those PDX amps is that they're differential-balanced and should be able to handle the BMW's attenuated output voltage, and they're stackable.

If you run two amps, you will not be able to use Technics' Add-an-Amp harness for both. You can use it on one amp, but the other will need to be spliced into the output wires of the head unit -- probably in a similar manner that you're installer did with the OEM unit, but from all four output channels, not just two.

OP, please read some of the threads that talk about amplifier installation. You'll gain a much better understanding of the OEM system, which you can then relay to whoever does your system install.

[M2withACC]

Originally Posted by Viffermike

I of the OEM system, which you can then relay to whoever does your system install.

Thank you Mike for the reply. I am getting a Match PP82 DSP installed tomorrow. I was going to get Helix P SIX / V EIGHT. M2 is quite noisy, I think Match is good enough for me. I am running 100KRS, IFBMW woofers, stock at rear. I kinda wanna go for Helix and use my focal/alpine amp to push the woofers. I plan to get Utopia soon!