Aerials & Leads
Airbag Crash Data
Bass CD`s
Cass / Tuner
CD / Tuner
CD Changer
Double Din
Installation Bits
iPod & Aux Control
Mileage Calibration
Mobile Phones
Repair Service
Search By Vehicle
Service Manuals
Spare Parts


Other manufacturers...

DND Services Ltd :: Project: BMW 3 Series Cabriolet - Steve J.

Project: BMW 3 Series Cabriolet - Steve J.

Steve J came to us one day and said that he wanted some serious Bass in his BMW. Not a problem, we said, and then he told us that his BMW was in fact a Cabriolet, and he wanted some Bass that was going to sound equally good with the top up or down. Then, to complicate matters even further, he said that it was important that he retained some boot space in the car. An impossible job you may think? Well, with a bit of radical planning, and one of our box designs, we were able to install a lot of Bass exactly where he wanted it, inside and outside of his Car.

The Box

This Project highlights the importance of Bass Enclosure Design. We all know the problems of non existant Bass in Cabriolets, And I bet most of you would laugh at the thought of using only two 8" Subwoofers to achieve a stunning Bass in any boot, Let alone a Cabriolet !

Have a listen to our box design using Cerwin Vega`s

Still Laughing? . . . . Or would you now like us to design one for You?

Inside The Boot

The Port from the Subwoofer Box is extended outwards, and passes through the two rear bulkheads underneath the Roof Storage box. This panel is part of the structural strength of the vehicle, and great care had to be taken, to remove as little material as possible, between the cross bracing.

Behind You

With the rear seat removed,you can now see where the flexible Port comes out. All we have to do now, is join it up.

(If only it were that simple !!)

The theory is that the port will run externally to the box and we will route it through the back seats to place the actual vent opening inside the cabin, in order to give maximum bass right behind the driver and passenger.

The Battery

The BMW has a very nice shaped compartment on the right hand side of the boot, and seemed to lend itself almost perfectly, to one of our favourite upgrades, the obligatory Delco Freedom Battery and split charging system.

We have found that the Delco battery outperforms most of its more expensive counterparts, and is certainly our battery of choice when running this kind of audio system.

No Ski Hatch !!

Problem is though, that we have picked the only BMW that does NOT have a built in hole for an armrest or Ski hatch.

Alan and Iain are performing Surgery on the rear seats, to make a hole for the Port to pass through.

The Port

Although there was no Armrest hole initially, the small panel insert that retained the seat belt clips, was removed and hollowed out to the same diameter as our Port.


A long armrest would not have suited the car, so a short one was fabricated and then trimmed in leather. A grill will be put over the end to prevent unwanted items falling down the hole.

You can still use the boot !

The rest of the boot was panelled, a CD changer was sunk into the left hand side, a box constructed around the battery on the right and then trimmed in a carpet matching the original one.

A useable Boot, with very little space taken up.

Steve J.

A Photo? You must be Joking !!
I haven`t washed or shaved !!

Don`t worry Steve,
We will darken the Photo a little.
No one will ever know !!

Your cart
Cart is empty

View cart
Orders history



Log in 
Recover password

If Javascript is disabled in your browser click here

1st May 2019
Services Resumed

Following some essential communications work behind the scenes, we are now back up and running again. Apologies for any inconvenience.


Copyright © 1992-2019 DND Services Ltd