My understanding from the motorcycle sound guys is that the better Class D amps really do sound pretty good. As has already been mentioned, the bandwidth for listening to a motorcycle stereo system is not as critical as that of home audio. I'm pretty sure that 'in-helmet' systems could emulate those of a good home headphone system. BUT...... I'm not so sure that there might not be some kind of safety issue associated with that kind of thing. If you imagine sitting on a deck with a beer and watching the BarBaQue.....if you had some sound going in the background, even if pretty loud, you could still hear other things going on. If you were kicked back with the cans on, you might not hear your wife screaming that the burgers were burning!! I guess my point is that while the struggle for good sound can certainly be achieved in some more effective ways.....there should probably be a line drawn somewhere that includes keeping things like hearing a horn honking within audible limits. I've been riding for nearly 55 years, getting my first bike at age 12 and now being 67. Only last year did I actually get a motorcycle that had an audio system. I only owned that bike for about 5 weeks.....and for the first 3 I had to do a lot of mechanical repairs. I then took off on a 10 day / 3000 mile trip. For the first 1500 miles I still didn't listen to the sound system (this bike was an '07 Street Glide with the stock HD system). Somewhere around the top of Michigan I decided to put in a CD and do some listening, and I was kind of 'hooked' from that point. I acquired a few more CDs on my stops along the way.....but sold that bike literally 2 days after I got back from my trip. Over the winter I bought and sold a few more motorcycles, all with audio systems, and finally ended up with this 2019 Street Glide Special. No more CD player, but I've now learned how to rip a CD and transcribe it to a stick drive in MP3 format and the bike plays those very well. It's just that the HD system, as supplied by the Factory, has a rather 'tubby' sound to it. For those HiFi guys who know how it feels to hear Horn speakers that can rather scream at you...this HD system has this 'speakers in a 55 gallon drum' sound to it that I find equally bothersome. Virtually everything I've read has indicated that the 'fix' is to install some better speakers, and put in a supplemental amplifier. This also includes utilization of this Line Level Adapter that has some filtering and adjusting capability, and supposedly also helps the entire upgrade. So, I guess we'll see how this all pans out. I have the speakers on order, as well as the line level adapter (Biketronics BT355), a mounting plate made specifically for installing amps in this model motorcycle, and even wiring kit. All this stuff should arrive this coming week. The only thing left is to make a decision on 'what amp to buy?' The choices are stacking up, but the recommendations still remain relatively slim. Mmats, Stinger, Hertz, JL, NVX, and a few more have made the consideration list. But, there's a pretty broad price range within some of these amps. The HD guys all say: "you get what you pay for!". I say you pay for what you get......then decide if you like it or not!
