Pitfalls of DRM in real life:
1. Technically provides low audio quality. In the UK, 98% of DAB stations (which are similar to DRM stations) were reported to be using a bit rate of 128 kbit/s with the MP2 audio codec, which provided much poorer sound quality than FM radio, with identical signal strength of both DAB and FM. Also, a large and growing number of DAB music stations were transmitting in mono, compared to the 20Hz-17KHz stereo transmission of the analog FM stations.
2. Faraday cage effect inside R.C.C. buildings wherein DAB signals can get blocked out.
3. The sound quality from the trials conducted by the BBC with DRM technology was better than AM quality, but not better than even the average DAB quality, i.e., DRM is inferior to DAB.
4. High establishment cost of the radio station. Higher cost of the receivers than the analog ones (unless Chinavasion rescues the average Indian by pumping in large number of "Made in China" DRM receivers across the borders). This, in a scenario, where most commercial analog FM stations have still not started making profit (and forget about the fate of rural / community radio stations).
Unfortunately, our honourable policy makers do not seem to read through the scam behind DRM radio. Not withstanding the experiences of countries like the UK, whose legacy we seem to be keen to import, our policy makers still talk about replacing the analog FM with DRM+. It will be a sad chapter in the history of Indian radio broadcasting if this happens.
It is important to note, that with decent FM signal, properly installed antenna and a good FM tuner, when the source is uncompressed digital stereo, what you get to listen to is nothing but uncompressed digital sound. It is a mistake to think that DAB+ / DRM+ will have better sound quality just because the transmission is digital.