[zamo_core18]

Hi everyone, first of all sorry for my english, i'm from Spain and don't speak it perfectly

So, my E90 came with Base Stereo and iDrive CCC. I went to a car audio workshop to install the MB Quart QM200.3 BMW Kit as well as a 4-channel classD analog amp (150W Max, 75W RMS at 4 ohm). The thing is that instead of using two channels for the tweeters and midrange, and the other two for the underseat subwoofers (as MB Quart states), they used only two channels (they installed a second crossover for the subwoofer i guess) and used the other two for the rear speakers (which are the OEM ones, and i deactivated through the fader setting recently because they sound horrible).

I'm going back to have the speakers wired as the guide says, but also i'm thinking of making some tweaks.

So my questions are:

• I want a bit more bass. Replace the underseat subs with Earthquakes SXS-8X or install a trunk sub (using the output for the rear speakers and a separate amp)? I've read that the trunk is well isolated, and i wouldn't like to lose too much trunk space
• In case of installing the trunk sub, would it be worth it to invest in a 4-channel amp and upgrade the rear speakers? Or how could I maintain them? Because they are used by the PDC. I don't care if they aren't amplified, maybe just leaving them connected directly to the HU and tapping the sub amp from them?
• Upgrade from CCC to CIC in terms of output quality?

Thanks for the help!

[ctuna]

1)Programming to Hi Fi outputs will do more for the sound quality
and or a dsp.
2)All the base speakers are crap.

http://www.e90post.com/forums/showth...ighlight=graph

Rear speakers are a waste of money.

https://www.e90post.com/forums/showt...highlight=base

many more like this just search do a search here with base in it.

[zamo_core18]

Originally Posted by ctuna

1)Programming to Hi Fi outputs will do more for the sound quality
and or a dsp.
2)All the base speakers are crap.

http://www.e90post.com/forums/showth...ighlight=graph

Rear speakers are a waste of money.

https://www.e90post.com/forums/showt...highlight=base

many more like this just search do a search here with base in it.

Oh yeah I previously coded my unit to HiFi ($676) and added an amp as well as the MB Quart speakers

Also I noticed that the AUX quality is way worse than CD (in comparison using the same MP3 file). I bought a Bluetooth LDAC amp/receiver like this to try:



I don't know if it's caused by a poor output by my phone/receiver or if it's a common thing (maybe CIC solves this?)

[ctuna]

Yes BMW aux is a crap input.
Extensively discussed in the following thread.
http://www.e90post.com/forums/showthread.php?t=1002984

The following is one of the cheapest solutions.
https://www.e90post.com/forums/showthread.php?t=1499808

Works well I have one only downside it the interface control is kind
of wonky.(to switch between sources you have to use the Rad off on switch
at least on the pro radio)

If the aux is the bottleneck it's the bottleneck.

[kaigoss69]

2 channels for the doors, 2 for the underseats, that will sound much better, and you will be able to control the levels separately, as well as the low-pass for the woofers. As far as trunk sub, infinite baffle sounds best, followed by corner loaded custom enclosure. Both don't take away much trunk space, which is what you want.