The OHM D can be upgraded to the sound quality of an OHM C2 with the addition of a dome tweeter and crossover harness. The upper treble response is extended to add sheen to cymbals and metallic quality to horns. To install this kit you must first cut a hole in the front panel (a template is provided) and then put in the crossover harness.

Both the C2 and the D2 can have tighter and deeper bass with the addition of a SubBass Activator (SBA) and our upgraded 10" woofer. The SBA eliminates the drive below the speaker's natural response to reduce distortion and clean up the deep bass. This allows for lower distortion, higher output and deeper bass, plus uses a self-resetting protection circuit. The upgraded woofers have a new cone/surround that is projected to last up to 30 years, while the FerroFluid cooling handles the thermo transients from CD's.

Another option available is the vent which allows for 1/3 octave deeper bass and also doubles the maximum sound pressure level in the bass. For installation you must cut a 2" circular hole (a template is provided) and then glue the new vent in.

Note: Most Ohm upgrades require no specialized knowledge and are easily completed completed by any person. It takes less time to install your own upgrade than it does to package and return ship your speakers to the factory, therefore, we recommend you save time and money by doing this yourself. We ship the upgrade to your door with clear, easy instructions. If for any reason you prefer to have the factory complete your upgrade installation, we will be happy to do this for free, however, you will be responsible for shipping and handling costs each way.

Ohm allows up to $400 for the return of a complete pair of undamaged Ohm D's toward the purchase price of new Ohm speakers.