Frequently, bus drivers ask for a resonable HIFI upgrade. The advice of experts is usually unanimous:
Proper 165mm low-mid-range drivers in the doors in conjunction with 100mm co-axial speakers in the dashboard driven by an amplifier. Advice on the right components is available in better places. We can deliver items for the special installation in the T4 with our parts.


Loudspeaker installation in the front doors - Gerda




There are several problems in the front doors:
The original TMT is directed downwards.
The original mounting uses loudspeaker baskets for 165mm TMT, which are expensive or no longer available.
The TMT does not have a volume to breathe because the interior of the door is not used.
If the above mentioned loudspeaker basket is applied, upgrade loudspeakers with a flat design are necessary.





Here is how Gerda helps:


Gerda allows the speaker diaphragm to be connected directly to the door volume. The inner door panel is cut open without any loss of stability.
Gerda offers a vertical bolting surface.
Gerda is screwed / riveted to the door structure in a very stable way.
Gerda transforms the loudspeaker and the door into a stable unit. The door panel is merely placed over this unit, so that the standard interior apperance is maintained.
Gerda even allows the use of 180mm or 200mm woofers.

To play all these advantages, Gerda also demands something:
The inner door panel must be drilled and cut.
The door trim must be cut open inside the door pocket.
Ribs must be removed from the back of the door trim.
Depending on the loudspeaker, an adapter ring made of aluminum or MDF is required.
For installation plan approx. 3 hours per side.




Amplifier Support - Gretchen




If only one amplifier is to be installed, the passenger's foot space can ideally be used for this purpose. This keeps cable length at bay and the seat consoles can be used for other useful things.

Gretchen replaces the footwell cover of the '96 car models. But transporters can also be equipped with Gretchen. Various mounting heights are provided for this purpose.

Thus, the amplifier can be attached to Gretchen and disappears almost invisibly above the passenger's feet.
However, creative V-Dubbbers have also used Gretchen to mount a CB radio or a small active subwoofer.
In order to give even more space for creativity, two rectangular cut-outs for the VW light (3B0 947 415 B) have been added.