Making an exhaust quieter?

How, other than a baffle, do you make an exhaust quieter.
Story is I've got a micron system and it's 104db and it's got a cannon on it (big can) and don't really have a clue why a m4 exhaust is only 98db so I know it's possible. Any help would be good.

I would thing a larger silencer is better than a small one if the internals are the same..ie, the perforated tube and the sound deadening material. I cut open a cheep silencer and found the perforated tube surrounded by about 1/2inch of wire wool, outside that was the white sound deadening material. The silencer body was about 500mm long but was hopeless at reducing noise, yet a similar sized silencer I got from Motad (one of there experimental units) was almost as quiet as a stock system but was straight through unit. Both silencers were fitted to my to my mx5 that gets driven hard and revs to about 7500rpm and neither had a performance advantage.

It might need re-packing. Do you know how many miles it's done?

If it's done a lot of miles the wadding which is sandwiched between the inner perforated tubes and the outer casing of the can has probably gone dry / hard and is no longer having the silencing effect it should.

I've no experience in re-packing a silencer but it may be worth looking into as suggested by monkey

Will give the repackaging a wirl as the end opens with Allen keys easily and get back to you with the outcome.

Repacking !

Last time I was without a baffle the guy at soundtest just laughed at me, 107 db, strict fellas down at Pembrey, baffle in 101db, maybe a repack is in order for me to.