The MTC single IS quite loud. When you rev it has that sharp sound that cuts right through. I lost my db-killer after a week or so after I got mine. I was *ashamed* while driving to work. Luckily MTC sent me a new one free of charge.

I still thought it was loud, though, so I ended up contacting them asking if they had a more quiet baffle I could buy. They did. Cost me 40� and I don't think it's that much quieter actually.

But if, like you say, bass travels further, then maybe it's just me sitting right on top of it that hears it the most. I've more or less gotten used to it by now, but I still drive veeeery carefully when passing police cars just in case