[Arjun9999]

Hey guys,

Recently picked up my dream car, a white F10 M sport, absolutely love it. Hate the audio. Cannot stand the lack of bass at all. Was tempted to put a sub in the boot but been told that its too isolated to produce good enough sound.

I was wondering what budget options would be suitable? I'm just hoping to fit an amp and replace the subs. Would a Vibe Powerbox provide enough to the underseat subs?

[SnowdenR]

Hi, first post on here and wanted to jump in on this topic as I've had the nightmare of trying to deal with this myself over the last year or so...

I'll start by sharing my story and where I'm at, how I got there etc..

F11 2014 535d Msport fitted with "base audio" ....😞
First thing I did was buy some HK speakers from eBay for about 100 a pair. Take note, fronts are larger than rears. Assuming the fronts must be 4.5" but don't know this for sure. So make sure to select a pair of rear and a pair of fronts.
These came with tweeters and tweeter housing but couldn't fit the rear tweeters as they didn't seem to fit anywhere. Think I need an adaptor here of some kind..
Other than that everything was a straight unplug/plugin job.
This definitely improved things very slightly but nowhere near enough.

So the next stage was to fit the mb quartz underseat subwoofers which I got from Amazon for around 150-200 I think.
Hate to say it but I really didn't notice much difference in bass. At best a very mild improvement if anything.

I then fitted an mmi android interface box which basically hooks up to the existing idrive screen and system etc to give me carplay etc. (This became the route cause of issues later on)

This gave me a better option for equalising the sound better but still... Not happy with performance yet.

After spending ages reading up online about possible setups that wouldn't cost me a bomb I found some positive reviews about this vibe powerbox 65.4 that hooks up the head unit plug and play and boosts your speakers to 65w per channel X4.
This definitely improved the volume and bass but the bass was poor quality and the speakers would clip at what I'd consider quite low volumes (60% roughly)
After adjusting the gains I managed to get a sound that was acceptable but still really lacking in punch.
What confused me most was that the underseat subs seemed to be playing only when I had the fader set to 0. If I went to rears only the subwoofer was only very faintly detectable, same if full front.
So I couldn't work out if the subs were feeding off the front channels or the rears, and tbh I still don't know.

Heard about maybe coding it to hifi, which having Carly and the dongle for some reason it could never access my idrive to code. Sometimes it would detect it but never successfully read from it.
Searched high and low for this problem with no real answer.
Then tried bimmercode.
Same thing, wouldn't read from head unit ECU..
So I remember reading somewhere about not being able to code your ECU if you have retro fitted android carplay etc, bla bla.. thought this didn't apply to me as I was still using original idrive setup just with an optional carplay box added.. however it clearly did as I'll get to in a minute.
With this new addition of the vibe powerbox I noticed it had RCA outputs that could feed to another amplifier.. 👀
So I thought ok, wiring a sub in the boot has now suddenly been made a lot easier. Even comes with the remote wire (orange one)
So that's what I did, and went and bought another mini vibe amp called a 400.1 I think. A mini mono block amp from Halfords for 70 quid.
Rated at 700 watts, which was perfect for my caliber 700w subwoofer I had sitting in my garage.
At same time I decided to try and remove my mmi box from behind my head unit and see if I could code in this hifi thing.
Success, I could now access my head unit ECU!
Carly didn't seem to have the option for hifi but did see bang and Olufsen setting which I tried out and at first I thought wow, it's worked,
It didn't...
So removed that and tried using bimmercode instead.
Found the setting for hifi in there and noticed how the volume had dropped significantly when I changed it.
So I turned up my gains on the powerbox 65.4 to max, things became a lot clearer suddenly, the clarity was better and the bass a lot punchier.
So this hifi setting basically hands over responsibility to the vibe amp and gives it a lower powered signal but the equalising is much better. Base audio compensates for lack of tweeters in its setup by over equalising the output. Hifi setting changes this to a much cleaner output.
Now I fitted my sub into the vibe 400.1 and adjusted the crossover on the amp things suddenly fell into place.
My bass was finally where it should be, my tweeters sounding clean, mids sounding punchy.

Question I have now is do I re add my mmi box for carplay now I've pretty much coded all the items I wanted. Removing it is a massive pain so ideally when it's in I don't want to remove it again so that I can code it.

Hope some of that helps, I'm not the best at explaining things but happy to answer any questions