I only have experience with 2 channel.. But yes I kept the kappas and changed amps

 

Great suggestions thus far but before u start jamming the "buy now with one click" button you really need to identify what u r trying to accomplish. Your most recent comparison was a CVO. What did u like about the sound? Was is just loud? Was it clear? Warm sounding?
How many speaks are u eventually going to run? Are u willing to step up to the next tier of speakers at some point? Are u willing to change HUs?
Ultimately what is ur hard line budget?

So many awesome options bro, but before u start this race u are going to kind of have a ruff idea what the finish line looks like or u will wander around throwing good money at results you may not be interested in.

Cool the jets just a bit and do some research and price shopping. Develop a sled audio system (with options / flexibility) on paper that at least defines the sandbox u want to play in and slowly work towards that goal. Don't think u r going to find one magic pill here that blows away all your pals systems as it is the entire package coming together that will make that happen. Does not have to be expensive, just smart.

T.

 

I've heard and installed that set up on quite a few bikes and I have to respectfully disagree. That amp and those speakers hit hard! I'm not sure what your expectations were and it's no where near the best. but for the cost of the amp and the speakers. it's a great set up. The Cerwin Vega is not gonna sound much better with those speakers. Your head unit is the biggest part of the issue.

 

Close to replacing the head unit , but sometimes use the communication feature. I have been reading and here is my plan. Try setting the levels again using a suggestion I read go to half volume on the HK and find the max distortion free level, Maybe try installing a high to low line converter? I have $500 max I can spend now if I have to. I know most think Harley audio is fair at best, but that New CVO street glide I rode yesterday 25 miles at 85 mph sounds awesome compared to my system.

 

I didn't matter how I had mine set up even with an aftermarket head unit it still sounded the same.. I bet I have some of the emails from haze from back then describing the same thing.. It got loud but the quality wasn't there

 

Very true bro. But keep in mind we're talking $350 bucks max for that set up.

 

Have you tried the tweeter button on those speakers?????
Also how do you have the tweeter facing behind the grill? Up ? Down ?
These two items alone will have some effect
May not be to the degree you are describing, but it will make a difference

 

I have installed that amp with a stock head Unit using both high and low level inputs.
The stock head unit shows distortion at about half volume. It was loud but had no depth to it. I hooked up a Sony hu to the system and it was a night and day difference from the stock hu in clarity and quality.
The infinity kappas are a good speaker for the money but we're a little bright to me.
I would suggest switching out the stock head unit.
Forum member LL247 has good pricing for the head unit ,install kit and hand control adapter.
Good luck on your search for the perfect sound

 

Everyone is bringing up very good points on this. I have to most agree with what Tailwind said. You have to really take a step back and think about what exactly you liked about your friends bikes sound.. Everyone has the sound they like. Some like the highs some like the warmer sounding stuff. There is so many options out there to upgrade your system. In my opinion I don't think there is a single person on this page that is wrong for those reasons. I have the infinity kappas in my big and they do sound good in my opinion. But.. I'm upgrading my system now as we speak because I would like to get some more sound out of it.

 

so basically the stock head unit is sending a distorted signal to amp which simply makes that signal louder?