Technology helps to give QB heads-up

From the outside, Matt Hasselbeck's helmet looks like any other. Peek inside, though, to see where the NFL meets Radio Shack.

In Hasselbeck's helmet, his backup helmet and the helmets of his backups, there is a battery, an audio module, an RF module and red-and-blue wiring, all equipment from Control Dynamics Corporation. All set up so that Seahawks coach Mike Holmgren can radio plays and instructions to his quarterback.

It works like this: Holmgren has a belt pack around his waist during games. When he hits a button on that belt pack, his words travel to a box upstairs, which is set to a specific frequency that sends those words to a stadium antenna and down to Hasselbeck's headgear.

For years, the Seahawks had only one box, but after it failed in New Orleans last season, they bought a backup system at the cost of about $15,000. Each box works on a different frequency, so when someone is on one frequency — like someone was in San Francisco this year — the Seahawks can switch to Hasselbeck's backup helmet and the corresponding backup system.

His backups, Seneca Wallace and David Greene, have helmets set up to the main box and main frequency, but their modules can be switched in a matter of minutes if Hasselbeck's helmets are not working. Which can happen.

"It can get knocked loose," Seahawks equipment manager Erik Kennedy says. "The speakers can come out. Just like anything else that's electronic, it wears down. A wire could fall loose. Water is also bad."

The equipment adds about half a pound to the weight of the helmet, enough, Kennedy says, so that Hasselbeck can feel a difference. The whole system is relatively easy to put together, but it must constantly be tested. Three hours before each game, the equipment staff tests the system at different points on the field to make sure the frequency is good to go.

The equipment staff can also control the volume in the helmet. Until there is 15 seconds left on the play clock, at which time someone from the NFL uses the "cut-off device," per NFL rules, to discontinue communication between coach and quarterback.

"You can't solely rely on the system," Kennedy says. "It's electronic. It's not 100 percent effective. But it works and really helps the offense. People take it for granted."