I had the short shots on before the Radii and the short shots were louder. But it was a very harsh, raspy sound that I didnt like. They also were hard to tune and the bike lost some of its low end torque. The Radii's baffles are like the old style Screamin Eagles and retain good low end TQ. Plus give nice volume but not raspy.

 

I also have the Radii (or Wyatt Gatling, depending on what you want to call them, who you bought them from, etc.) and they give you the "Harley" sound. I had SEII's on my 883 (similar to the Radii, just the Harley version back when they still made them) and while it had a similar tone, the volume wasn't there, but on the 1200 it's a different story. Sounds great, and IMO, better than most bigger bikes I've come across.

 

Sound is a personal preference.

A Sportster with V&H slip-on's sounds better than my Wide Glide with V&H Big Radius.

One thing to note about Big Twins in that a lot of them have cats in the header or collector before the mufflers. So, putting slips-on's on a BT may not change the sound as much as you expect. As far as I know, Sportsters do not have cats in the header pipe.

It sounds as if the sportsters have a different cadence to the firing. WHY Sportsters sound different than BT - I don't know.

 

Sporty's can sound just as good, and I prefer the slightly more offbeat cadence wideglideguy mentioned. Not quite as deep as the big twin, but very close and just more interesting sounding to me...

Otherwise idle is just as fast as EFI big twins.

 

My Sportster 1200 with Cycle Shack pipes sounds like a beast.

 

It's the single-pin crank, not the angle of the cylinders, that give a Harley its sound.
Valve-train noise, may have an influence, too. Push-rods vs. over-head cams in some UJMs or European bikes. Sportsters sound more hot rod than big twins, to me. An Evo motor, Block-head, sounds better than a Twinkie, Fat-head (particularly, a FI twin-cam). A Shovel sounds better than a Evo. A pan, sounds better than a Shovel, but you don't get to hear a Pan, very often. Unfortunately, I'm not too familiar with Knuckles or Flat-Heads. That "lope" sound comes from the timing, idle, cam and single-pin crank, more than the number of cylinders or angle. They all sound better than an in-line four, unless you're riding an in-line ***** out, or a two-stroke (whole nuther level). Parallel twins, sound good, too, if you're in the saddle - quick and a blast to ride. Truimph 3-cylinders sound funny, but they're all better than a V-6 cager. Hard to beat the low-end torque of a V-twin, or V-four, though.

 

Really cool.

 

Big twins don't sound like a racy Sportster but thats ok. Nothing sounds badder than a carbed Sporty on drag pipes. To loud of for my liking but it is what it is.

 

My 2008 1200 105 anniversary issue has Screami'n Eagle mufflers which are 21/2 inch pipes with baffles. When you get on it it sounds good, at idle, most of the time the idle is not quite potato-potato but it definitely has the cool, Harley sound everyone wants.
The standard pipes don't cut it, the slasher short-shots etc may be cool and loud but may also be illegal, not that I mind that but off the production line my 1200 needs no modifications to be cool.

cheers to all,

.

 

The best sounding 'Harley' I've ever heard was a Buell- which is just a Sportster engine with a better crank, heads, and exhaust than what was put on the factory sportsters at the time.
IMO, my sportster sounds a lot better than my Dyna, though the sound gets a little too loud and harsh at freeway speeds.