I don't know if anyone cares but here is the volume (noise) level measured by my iPhone:
OEM 80dB
Delkevic with Baffle 85dB
Delkevic w/o Baffle 90dB
The reason for quieter than say Muzzy are:
1. Exhaust opening (namely the diameter of perforated tube inside the muffler) is 1/2" smaller
2. Perforated tube is not straight design but has four protrusions inside where (I believe) the tip of the dB killer sits.
Pros on Delkevic:
1. Inexpensive
2. Very well made
3. Super fast shipping and good customer support
4. Excellent fit
5. Quieter than other slip-ons
6. Center stand stopper built into the mid-pipe
7. Their logo is engraved on the muffler with a very nice touch. In California, we don't want to get attention from LEO. SO Delkevic's logo handling is very good
Cons on Delkevic:
1. Installation manual not easy to read (OK, not that anyone needs it but just in case)
2. How about the power coating option? I wanted to get black muffler but not carbon fiber. Power coated black like Muzzy would have been nice even if at some extra cost
I will see how long the muffler/packing will last. So far with 100 miles on them, I am extremely happy with Delkevic.
1973 Suzuki GT250, 1976 Kawasaki KH500A8, 1979 Yamaha RD350, 1985 Yamaha Maxim700X, 1987 Kawasaki EX500, 1994 Honda CBR600F2, 2004 BMW R1100S, 2005 Kawasaki Z750S, 2003 Suzuki SV1000N