Yes, this is true, it is a selling point of DRM to operators, saying that you can run less power with the same listener impact (in theory) and I understand the technical reasons (interference etc).
In reality it does not translate to that unless good receivers/antennas are used with an excellent signal to noise ratio but this unfortunately is only afforded by enthusiasts...like us...consumers struggle to receive low power DRM transmissions which has been proved on a number of occasions (by me and others). When I had the DR111 (and currently test using the MR 27024) I can/could only receive AIR, REE and RRI consistently using the whip under stable propagation conditions, all these stations use power >50kW.
Sure, run lower power but not so low that the signal can't be received by the listener. DRM is either there or it isn't, people are not going to sit and listen for 10% audio (where 90% is silent).
Originally Posted by DRM-OM
Note that total DRM power is limited to max. 40% if analog CARRIER only power for technical reasons. So don't expect more power.
This is a feature.
DRM is "sold" to transmitter operators with the arguement to save energy = money!