I'm guessing the only real place is glove box , unless you make a box to sit above the Air vent
I want to keep it classy glovebox is the best location by far it isn't accessible whilst driving the biggest down side. A box on the air vent is too revealing lol my aim is for some kind of sleeper sound system
It is going to be difficult to get the bass sound you want - its probably going to take a lot of work/ money to achieve
One suggestion is fitting "infrasonic" filters (high pass filters) to the existing door speakers, - this basically stops the bass getting to the door speakers, so the door speakers can handle more power/ volume - and the sub handles all the bass - the active x-over frequency in the sub would be adjusted to compliment the roll- of frequency of the door speakers (with the "infrasonic" filters installed)
This would just be an interim solution because ultimately you will really need to replace all the speakers/ amps etc and "beef up" the electrics (audio battery/ capacitor etc) to cope with the bootful of amps you would need
At the momment the head unit is limiting the bass/ volume with a built-in compressor -(and/ or the autovolume is adjusting the volume) it may be possible to disable these features - but watch you dont blow your speakers/ amp by overdriving them
You would have to use cd-s as a source because mp-3s remove some of the bass
Exactly the real issue is the built in compressor, i never thought about researching how to disable it as i thought it wasn't possible, i wont look into it anyways because the travelpilot system does not have any outputs for a sub.
I already have the main parts to build it all, a 1000 watt RMS sub 2x500 watt in one enclosure with a 1500 watt rms amp, a big wiring kit and a very old kenwood head unit beaten up but still working, taken from my first car. The head unit will be upgraded in the future because it doesn't even support aux input.
The glovebox idea is best so far and would be great if i could find a head unit with remote (wired remote)
Now leaves me with no place to put 4 additional speakers