For my last three cars , I have been using KEF B139's , which are widely held to be the finest Hi-Fi low frequency unit ever produced , being widely used by manufacturers such as Linn , Radford , Ferrograph and many others besides KEF themselves and , of course , IMF who are famous for their transmission line loudspeakers , like the TLS 80's I have in my living room .
It just so happens that , with W201 and W126 models , that if you pop out the plastic first aid kit carrier , the aperture left in the metal shelf underneath is a perfect fit for a B139 . In each of my cars I have fabricated an MDF shelf to mount the units in and then placed material over the top to obtain an 'invisible' installation . No damage is done to the car and the installation is completely reversible . In the case of the 190E 2.6 I trimmed the shelf in some black 'contract' carpet which matched the interior of the car and was transparent to the bass notes , the coaxial speakers at each side were fitted with the supplied covers .
With the W126 , an added bonus comes in the shelf accomodating 2x B139's , thanks to the twin apertures in the shelf , coaxial speakers being fitted in the existing 'pods' . On this car , I used a double layer of 2x 18mm MDF sandwiched together for rigidity .
Electronics in each case were mounted on an MDF sheet fitted in front of the petrol tank .
Here are a few pics
Firstly , a B139 lined up over the first aid kit lid in a 190E
Showing the bare MDF shelf before trim goes back
Electronics mounted in the boot of the 190E 2.6
Views from below the shelf in the W126
And the rest of the electronics in the boot of the W126
The Sony XRC900RDS head unit installed in the dash of the W126 , I have an identical unit in the W201 , these are both 'flagship' radio cassette units with no onboard amplification and , importantly , the display can be set to completely blank when driving so is not a distraction . I also have the CD version , the CDX910 but it lacks the diversity tuner and telephone mute facilities , so is currently in storage in the attic . These are still widely regarded , 20 years on as amongst the best head units ever made .
The sound from the B139's is very natural with extended bass and no hint of 'booming' . The other speakers are JBL units , but I am always looking out for some of the elusive KEF KAR units produced in the 1980's .