[devil84]

What amp is it? A 2 channel amp just to power the underseat subs?

Did you find that the HK amp was freed up to power the remaining speakers. I am thinking of going down the same route.

I will be using the technic pnp.

I am looking at the sr4.500 and bridging two channels to power a sub and thr remaining 2 to power the HK woofers

[t5pilot]

Originally Posted by devil84

What amp is it? A 2 channel amp just to power the underseat subs?

Did you find that the HK amp was freed up to power the remaining speakers. I am thinking of going down the same route.

I will be using the technic pnp.

I am looking at the sr4.500 and bridging two channels to power a sub and thr remaining 2 to power the HK woofers

Have a read of this mate. You may find it useful.
If you don't want to, my additional amp is a Hertz HCP-2X

https://forums.m3cutters.co.uk/threa...ptions.228786/

[Ian_Mac]

HK certainly seems to kick out plenty of bass in my F30

[cramsnik]

This is probably a daft question to those in the know but I assume I should be able to feel some vibration from the under-seat subs? I've stuck my head under the seat and cannot hear anything bar the music from the door speakers.

Compared to the Bose setup I had in my Audi the BMW HK setup has always been a bit of a letdown. In the Audi I could really crank the music up, it never seemed to distort and sounded really crisp. The BMW system seems pretty lifeless and muddy in comparison.

[t5pilot]

Turn the bass up then the volume up. If they're working you will hear them & your outer door sills will probably rattle.
Otherwise, there's a problem...

[Techno 9000]

Originally Posted by cramsnik

...I assume I should be able to feel some vibration from the under-seat subs? I've stuck my head under the seat and cannot hear anything bar the music from the door speakers.
... The BMW system seems pretty lifeless and muddy in comparison.

Given the under seat speakers are fixed securely to the metal of the floor I would be surprised if much vibration could be felt, I cant say I have tried though.

The HK system in my 2015 435 was poor, you could call it muddy, until I adjusted the equalisation appropriately.

The fact that you feel that the sound is muddy suggests to me that the bass, from the under seat speakers, is present. Otherwise the door speakers at 100mm (4") don't have the size to sound muddy (bassy) in themselves (assuming the treble hasn't been turned right down).

Try the equalisation, fader and balance from this post and see if it improves things for you. It's not meant to be for your vehicle, as its based on a 4GC but, given that some people with HK systems are unhappy with the sound, it seems that the default EQ is far from perfect. You'll see one member with an F31 found it helped.

[330Stevie]

My 10 year old loves Ariana grande….her stuff is on quite a bit! Her track “7 rings” will show you if the subs are working! If you play it and don’t know what I mean then there is a problem with the subs….

[cramsnik]

Cheers for this, I've now tried out these settings and it does sound better. Compared to the Bose system it seems you really have to push the volume to make the HK setup stand up and be noticed. maybe it's just on my car but you don't feel a kick until I'm at some ridiculous volume.

Originally Posted by Techno 9000

Given the under seat speakers are fixed securely to the metal of the floor I would be surprised if much vibration could be felt, I cant say I have tried though.

The HK system in my 2015 435 was poor, you could call it muddy, until I adjusted the equalisation appropriately.

The fact that you feel that the sound is muddy suggests to me that the bass, from the under seat speakers, is present. Otherwise the door speakers at 100mm (4") don't have the size to sound muddy (bassy) in themselves (assuming the treble hasn't been turned right down).

Try the equalisation, fader and balance from this post and see if it improves things for you. It's not meant to be for your vehicle, as its based on a 4GC but, given that some people with HK systems are unhappy with the sound, it seems that the default EQ is far from perfect. You'll see one member with an F31 found it helped.

[johnung]

Originally Posted by cramsnik

This is probably a daft question to those in the know but I assume I should be able to feel some vibration from the under-seat subs? I've stuck my head under the seat and cannot hear anything bar the music from the door speakers.

Compared to the Bose setup I had in my Audi the BMW HK setup has always been a bit of a letdown. In the Audi I could really crank the music up, it never seemed to distort and sounded really crisp. The BMW system seems pretty lifeless and muddy in comparison.

Just put your hand under the seat on the subwoofer grille to feel if it is working. See photo for location of the subwoofer and appearance of the grille