The noise is at 115.6 decibels. Louder than the mosh pit at a metal concert.
Istora is at least that loud. It could probably go louder, but the needle on the free apps you can download on your phone only goes so far. This in the nosebleed section. On the four courts, players are probably targetted by a tsunami of noise. Rock concerts are hosted here too, and you can see why.
Certain venues are iconic for sports. Lord's for cricket. Wimbledon for tennis. Istora is iconic too but closer to Arthur Ashe at the US Open or the Maracana for football sort of way. The Istora Gelora Bung Karno is the loud, beating heart of Indonesian badminton, a place of history and heritage and noise. Its strawberries and cream is spicy Kerak Telor. However, in a concession to modernity, you aren't allowed to smoke cigarettes in here anymore.
Playing in Istora is an experience by itself. For players used to polite claps and sometimes sparse crowds, the heaving 7000-strong crowd egged on by an energised hypemaster draped in red and white flags and wearing a military style cap, is something else.
"It's crazy. It's like you are playing in a football stadium. It's how cricket or football matches are played," says Saina Nehwal, who competed against Indonesia's Fitriani Fitriani.
She has a point. "Today we believe we will win," goes a football style chant across the stadium.
Badminton is an inseparable part of Indonesian sporting culture. Ever since Tan Joe Hok, a member of the often discriminated Chinese-Indonesian minority, won the 1957 All England title, earning national glory for the still nascent nation, the sport has served as the unifying glue for the often fractious people of this diverse country. And there's no place where the faithful seem as one as they do at the Istora.
It is only appropriate. It is right here that the country hosted the badminton events at the 1962 Games, winning five gold medals out of six. It is where Rudy Hartono won the World Championships in 1980 and the national team won the Thomas Cup in 1996.
"Istora is home to some of the greatest stories of Indonesian badminton. It is Indonesian badminton's home," says veteran journalist Nurul Hamami, who has covered matches here for the past three decades.
Here is home advantage if there ever was any.
If you can't take the pressure, just pray you don't draw an Indonesian. This is pro-sport viewed like sport entertainment. Any team on the other side of the net is a pantomime villain.
"If you are playing against them (an Indonesian), then you've had it. I still think they managed to pull Rudy Hartono (who was close to the end of his career at that point) through to the World Championship gold on their willpower alone," says Vimal Kumar, who played here in the 1980s.
"It is noisy, there would be people smoking cigarettes and flicking ashes and they will let you know they want you to lose. Indonesian people keep coming and going. Noisy. You really have to focus."
Istora has always been this way, says Hamami. In fact, you could even say it has mellowed. For one, matches aren't called off anymore due to crowd trouble.
"Back in the 1967 Thomas Cup, the spectators booed the Malaysian players so much that they eventually decided they didn't want to continue the match. Of course the referee had to award the Cup to Malaysia," he says.
Saina knows what it's like. "When you are playing against Indonesia. It's as if you are playing the entire crowd."
Indeed, the crowd consistently lift their own players. India would know, having lost their team match to the hosts, despite fielding higher ranked players in the singles categories. "Every Indonesian player will say this. That they possibly get maybe 50 percent more energy when they play here," says Hamami.
But not always.
Saina and later PV Sindhu, who is playing Gregoria Mariska Tunjung, don't let a repeat of the men's result happen. There are moments of inspiration, though brief. After losing the first game 21-6, Fitriani found a second wind to lead 9-5 at one stage before the Indian eventually came through 21-6, 21-14. Sindhu, too, won 21-12, 21-15.
But when the Indonesian contest ends, the crowd is still known to be fair. They seem to have a soft corner for the Indians and in particular Saina, who has won three Indonesian Open titles at this very venue.
"They will support Indonesians but when I won for the first time, I had to beat three Chinese players back to back. And at that time the crowd was with me," she remembers.
While the Indonesian women's campaign might have come to a close at the hands of the Indians, Istora will not be silenced anytime soon. Jonatan Christie has already been willed to a victory over Shi Yuqi, China's gold medallist in the team event. And on Saturday, in the upset of the tournament, Anthony Ginting, who had been stretchered off the court during Indonesia's loss to China in the men's team finals, miraculously recovered to beat world champion Kento Momota. No Indonesian has ever won gold since Taufik Hidayat in 2006 and all of Jakarta is hoping their favourite son will help them find their voice once again.
Istora will continue to turn up the volume over the next couple of days.