[smojo]

I wanted the best possible audio, so of course I got the Harmon Kardon branded system in my '18 F34 340i.

Unfortunately, I'm pretty disappointed by it. My previous daily driver (E85) had the top DSP system with the amplifier in the trunk and subs behind the seats, all factory. I know it's not a fair comparison, but I was hoping HK would be better than it is.

Has anyone made any small improvements to speakers/amps/subs in the F34 that made a nice difference? I don't want to replace every speaker, but when a song with a little bass comes on, it sounds like I'm carrying aluminum cans in the car.

The speakers under the front seats seem like a good place to start. Any advice from someone who's done this before?

[Billfitz]

There's nothing wrong with the speakers. The amp is marginal where power is concerned, and the EQ isn't very good. A better DSP for the EQ would help, but at this point none exist other than in replacement amps, and those can't be adjusted in iDrive. There are quite a few threads about those in https://f30.bimmerpost.com/forums/fo...play.php?f=426
Even with a better amp and DSP there's only so much you can get out of the under seat woofers. Big bass needs big drivers and enclosures, which means trunk mounted.

[KRS_SN]

ive read on other threads that disabling the active sound design module by coding can free up the speakers clarity on the HK audio. I have a HK system and I am pleased with it though haven't gotten around to coding off the ASD yet .

[Billfitz]

Is ASD still a thing? I always thought it was silly.

[KRS_SN]

Originally Posted by Billfitz

Is ASD still a thing? I always thought it was silly.

sadly it is . when i switch from comfort to msport a god awful drone is played through the hk speakers. I thus avoid msport mode like the plague. I am aware I can code this off and but I am too much of a pussy to try this though I have bought the obd2 vgate adapter and bimmercode app I love my f34 and worry that my coding attempt will cause something horrific to happen.

[Billfitz]

You'd think there'd be a way to get rid of ASD in the settings menu. I don't have it, so I've never looked into it. I doubt you can hurt anything with bimmercode so long as you don't go into expert mode and mess around with stuff you don't understand. I did my coding with E-Sys, it's worth it learning how to code just to get rid of the stupid disclaimer display on the screen every time you start the car. That might be a US only thing, meant to head off frivolous product liability lawsuits that clog up our legal system.

[KRS_SN]

absolutely I don't know why asd on/ off isnt available on idrive. You are lucky you don't have it it is a grim drone that pollutes a quiet engine The discaimer does not appear in the UK cars though.

[smojo]

Originally Posted by Billfitz

There's nothing wrong with the speakers. The amp is marginal where power is concerned, and the EQ isn't very good. A better DSP for the EQ would help, but at this point none exist other than in replacement amps, and those can't be adjusted in iDrive. There are quite a few threads about those in https://f30.bimmerpost.com/forums/fo...play.php?f=426
Even with a better amp and DSP there's only so much you can get out of the under seat woofers. Big bass needs big drivers and enclosures, which means trunk mounted.

Thanks for the tip! I started with glennQNYC's EQ recommendation and it sounds a lot better already. I made a few tweaks to increase bass and it's closer to what I want.

I read more about coding HK systems to use the B&O DSP settings within iDrive.

Has anyone tried coding this in an F34?

[Vinnie Stix]

It works and sounds great...Just follow these instructions posted here...It's a little different but you'll get the drift!

[smojo]

Originally Posted by Vinnie Stix

It works and sounds great...Just follow these instructions posted here...It's a little different but you'll get the drift!

I did it earlier today, I agree it sounds even better.

While I was hunting for that coding option, I saw a similar one: High_End_Audio_B_Und_W

Any idea what that one is for? Bowers and Wilkins maybe? I left it on the HK setting of kein_menue but it has the similarly named B&O option of volle_insz in there too.

[rambleon84]

Originally Posted by smojo

I did it earlier today, I agree it sounds even better.

While I was hunting for that coding option, I saw a similar one: High_End_Audio_B_Und_W

Any idea what that one is for? Bowers and Wilkins maybe? I left it on the HK setting of kein_menue but it has the similarly named B&O option of volle_insz in there too.

sorry to bump an older thread but yes, that would be B&W but as far as i know, its never been on option on these cars. I saw the new 8 series have them as a $3,400 option but didnt take the time to sit and listen though:


Starting to see B&W in higher trim cars:
https://www.bowerswilkins.com/car-audio/bmw

Looks like they are options on 5 series up.


I dont have any experience with them but I saw these guys do under the seat sub replacements. As far as ease of installing (as opposed to doing a proper trunk setup) this might be a good place to start:
https://www.bavsound.com/BMW-Underse...oofer-Upgrades

They claim gains of 10dB and free 100 day trial/shipping returns. If the price isnt out of your range, might be worth it to try

[Ha11z]

Seen some posts on here that say coding to B&W improves the sound on HK but not fired up ESys for months to try it myself.

[Billfitz]

Originally Posted by rambleon84

They claim gains of 10dB

Impossible. That's the equivalent of a JB4 tune claiming to double your horsepower.

[vhs04]

Originally Posted by Billfitz

There's nothing wrong with the speakers. The amp is marginal where power is concerned, and the EQ isn't very good. A better DSP for the EQ would help, but at this point none exist other than in replacement amps, and those can't be adjusted in iDrive. There are quite a few threads about those in https://f30.bimmerpost.com/forums/fo...play.php?f=426
Even with a better amp and DSP there's only so much you can get out of the under seat woofers. Big bass needs big drivers and enclosures, which means trunk mounted.

Can we high pass underseat hk subwoofers (to have them play 80hz+, for example) in any way (active/passive), still preserving the oem hk amp?

Thanks,

[Billfitz]

There's no way to adjust the OEM amp DSP pre-shape, so level reduction only below 80Hz isn't possible. The 100Hz slider in the H-K EQ won't help. The best you can do is to lower the bass tone control.
A passive high pass filter would work. It would have to be second order to have any effect, which requires an 11mH inductor and 350uF capacitor. You'd need a pair of them. I'm assuming you have 4 ohm woofers, if not you'd have to calculate the component values here:
https://www.diyaudioandvideo.com/Cal...akerCrossover/

They don't have an actual high pass filter calculator, so what you'd do is calculate a 2-Way Butterworth crossover at 80Hz. What's shown as the circuit for the tweeter would be your woofer high pass.

[vhs04]

Originally Posted by Billfitz

There's no way to adjust the OEM amp DSP pre-shape, so level reduction only below 80Hz isn't possible. The 100Hz slider in the H-K EQ won't help. The best you can do is to lower the bass tone control.
A passive high pass filter would work. It would have to be second order to have any effect, which requires an 11mH inductor and 350uF capacitor. You'd need a pair of them. I'm assuming you have 4 ohm woofers, if not you'd have to calculate the component values here:
https://www.diyaudioandvideo.com/Cal...akerCrossover/

They don't have an actual high pass filter calculator, so what you'd do is calculate a 2-Way Butterworth crossover at 80Hz. What's shown as the circuit for the tweeter would be your woofer high pass.

Thanks for the speedy reply.

The woofers from the hk tophifi are 32V 125w @ 8 ohm.

May I ask what would be the consequences of using a passive hpf?

My main points of focus are sound quality and time alignment(the end goal would be to couple them with a trunk sub) and phase control

[Billfitz]

None of the concerns you have exist in the subwoofer frequencies unless you use a full 2nd order/2nd order passive crossover, which you are not. You do have to make sure your trunk sub is wired with the correct polarity, which you would test by running an 80Hz tone. Try the polarity both ways, the louder is the correct polarity. If there's no difference it's still correct.

[vhs04]

Gotcha, thanks for the details.

In my case it’ll be the 2nd order 23mH with 176mfd.

Kind regards

[Billfitz]

When you see the price of those inductors you'll understand why passives are seldom used at low frequencies. Make sure the DCR of the inductor is no more than 0.8 ohms, which will probably mean using a cored inductor. You might not even be able to find 23mH, but 20mH will do.

[vhs04]

Thanks for the help, highly appreciated

[vhs04]

Originally Posted by Billfitz

When you see the price of those inductors you'll understand why passives are seldom used at low frequencies. Make sure the DCR of the inductor is no more than 0.8 ohms, which will probably mean using a cored inductor. You might not even be able to find 23mH, but 20mH will do.

You were right, they are hard to find. Also a high chance of hit/miss.

Did some more digging and it seems that I can only go the dsp+separate amp for the underseats route.

After reading another thread (f30.bimmerpost.com/forums/showthread.php?t=1356617) it seems that even if I’d add a separate sub and do a highpass there will still be a gap in the 120-180hz area. From what I understand this can be adjusted with the help of a voltage converter which will ingest the door signals(16V) and the woofer signals(32V), level them to line level and feed them to a dsp for processing and then to one /two separate amps (one for a trunk sub, one for the underseats)

Is this assumption correct?

[Billfitz]

There are issues with respect to overall response. My system has dips at 180 and 400Hz. It has nothing to do with the subs. That range is all coming from the door speakers. When I measured them nearfield neither the fronts nor the rears have any dip there. When measured at the driver's seat with all four running the dips appear. To make sure it wasn't a polarity issue with respect to the subs I reversed the sub polarity and it made no difference. Dips of that sort are to be expected when you have four speakers separated by the distance that they are. Ideally those speakers would all be well over 1/2 wavelength apart within their pass band. Since 1/2 wavelength at 180Hz is about 1 meter you can see the problem. There's just so much you can do within the confines of a car.

With regards to inductors look for the Jantzen brand. They're made in Denmark, so someone over there must sell them.