The Response D38 has successfully been in production for nearly 8 years, but with new cone technology now available to ProAc, the decision was made to upgrade this model and hence the new Response D40R was born. We now produce our own drive unit cones and, in particular, the carbon fibre cones utilised in the bass drivers of our Carbon Pro series of ultimate loudspeakers. These drivers produce the incredibly tuneful and powerful bass qualities associated with the CP6 and CP8 and the special carbon fibre technology has been further developed in order to produce a cone that will effectively cover both the bass and also the midrange frequencies of the D40.