I'm assuming that static decibels are the same as stock for the Akra slip-on with the blocking plate. However, if you get the wireless kit then it replaces the blocking plate with a valve that you can open at the press of a button and increase the noise level (I assume to louder than stock).
Originally Posted by Akra's website:
However, the muffler system is built in such a way that by replacing a blocking plate with our Wireless Kit valve system the driver is able to noticeably increase the volume of the exhaust at the press of a button. Once activated, the majority of the exhaust gases route through the muffler bypass outlets
Alternatively, I believe you can buy the Akra slip-on without the wireless kit and then manually remove the blocking plate so that you permanently get the increased noise level all the time.