It is the biggest and the most robust sound system on planet earth. Nothing comes close to it at all. The other being that of Masjid Nabvi.
So what does the Mecca / Haram system look like ... ? In brief ...
It has its own power plant and a backup power plant and a backup battery power to run the system. Every mic stand has 9 microphones, 3 for Qiyaam, 3 for Ruku and 3 for Sujood (the mics appear to be Sennheiser M408). If one of the three fail the other two will capture imams voice. If all the 9 mics on the stand fail, the policeman will grab another stand from nearby. There are 7 such stands with 9 microphones on them in the lower white marble area.
All these microphones feed into the best imaginable Midas consoles. More than 350 amplifiers drive thousands of speakers from Phillips, AXYS Intellivox, Dynacord, Community, Bose etc. Every piece of gear is computer controlled and has a backup to fail over to. A giant 3-D computer model is used to make adjustments on screen.
The mauzzan delivers azaan from a glass enclosure into several microphones. Shure sm58's, beta 58's, sm86, sennheisers, audio technicas etc. microphones pickup the mauzzan's azaan.
The system throws sound for miles in all directions all the time. Massive minaret speakers can be heard all around the city. There is a team of engineers managing the system all the time. This system never stops.
The Haram sound systems are huge in terms of their size but they fail in terms of clarity and fidelity especially the one in Mecca. Sound quality is acceptable only in the white marble region on which the KABA stands. We wish acoustics were given more priority over aesthetics.
The system in Medina is comparable to the one in Mecca and in fact overall sounds little better. The sound quality is even all over the masjid unlike Mecca. Here are some pictures about it.
Medina Sound System Pictures ...