Since my amp mount still hasn't arrived, and I continue to worry whether my HK eBay head unit will turn out to be a scammer, I went through and traced the pinout of the RadioSound head unit 23-pin connector. Pins 10 and 20 go to the battery through the RADIO MEMORY fuse, and pin 12 is a switched power lead through the RADIO POWER fuse. Along with pins 11 and 19 going to ground, how many of these wires do I need to connect to a bench power supply to properly power the head unit for testing out of the bike: all three B+ and both grounds, or some subset of them?

The reason I'm pulling the old radio in favor of the HK unit is because I am led to believe I've overdriven the internal amp and damaged it- turns out stock speakers were in fact 8Ω, not 4Ω like what's installed, so after about 11 years of too low impedance, the head unit amp is clipping pretty badly now. My goal is to experiment with adding pre-amp outputs to this unit a la ICA's upgrade for HK units. Has anyone ever tried this on the old RadioSound units?

Thirdly, my goal is to upgrade from the current MB Quart speakers in the faring to the Polks, and add rear speakers with the Hogtunes pods. With my using the Soundstream PN4.520D, can I use the 4Ω MBQ's in the rears, or will mixing 2Ω and 4Ω on this amp not work/be bad? And if/when I upgrade the rears too to Polks, do the Hogtunes pods work with 6.5" speakers? They speak of being directly compatible with the stock 5.25", but I want to be able to drop in larger speakers that match the faring pair in the future.

 

for ease of testing leave 11 and 19 alone and simply ground the case of the radio instead. 10, 20, and 12 must be connected for power.

Iron Cross Audio doesn't fool with RadioSound head units. The internal wiring on these units is more than likely different than that of the HK units. My .02 on this is simply the fact that the head unit has obviously been driven beyond it's capabilities for some time with 4 ohm vs 8 ohm speakers and damaged the audio output ICs. With that being said, it would not be beyond comprehension that the preamp stage is also an issue. So my .02 is use it for target practice. Would sure hate to see you add preamps and then either stick it back in your bike or sell it off to someone else and issues are still present. Wasted time and wasted effort. Time much better spent polishing chrome or running wires for your new setup.

2 ohm vs 4 ohm is not a concern when you have the power to deal with it. In your case (PN4.520D) you do have the necessary power to drive either effectively. You'll simply be turning your gains up on the rear a tad bit more than the front.

Polk MM and DB series speakers drop right into a 5.25" cutout without modification and only needing to drill new screw mounting holes for the polks.

 

Yeah, the RS pre-amp project is more just to prove that I can. I don't intend to sell the unit, just maybe keep it as a backup for when I need to have work done on the HK (if and when I ever get the thing).

 

ICA is very good at providing information, regardless of what kind of information it is as long as it helps the users/owners.

RS, not so much. So with that said, be sure to take pics and post a write up as I'm sure it will be used by many wanting to know how to add preouts to a RS unit.