The goal of this will be a running thread to routinely add new information as I get it. There was a guy who posted on Facebook an installation of an Alpine amp in the fairing that I would like to get the pictures and include in this thread. It was a good example of a "correct" installation.
This is a post for what I did to my bike, what I have seen others do, and to help anyone else who is going to do the same.
Great news, technology has advanced to give us GOOD sounding class D amps in VERY small packages. The last year or two 2012-2014 a whole new group of amplifiers have been offered making bike audio easier and better than ever.
Your decision will be based on the "other" personalizations you will do to your bike. For ME the audio was on the top of the priority list so that meant I wanted a good quality system that was protected. That meant the amp would be under the seat instead of under the trunk or in a saddle bag. Some others decided that relays, air horn compressors and other gadgets had a higher priority and they put those under the seat. To each their own and only you can decide which way you car to proceed.
The factory radio on the Interstate plays to two front 3 Ohm speakers and if you have the rear speaker option it also plays to two 3 Ohm rear speakers.
If you change speakers they will most likely sound better but play lower since the new ones will most likely be 4 Ohms and less sensitive. That is why we usually add an amplifier. However if you remove the factory speakers and run the factory speaker wires into the amp inputs and the amp outputs to the new aftermarket speakers the radio doesn't "see a load" so the voltage needed to drive the amp inputs isn't developed until the radio volume is turned up to the higher side. That is why an amp with variable inputs is nice, so you can match the level of the amp inputs to the level of the factory radio outputs.
Next is an amp with built in cross over. Since we only have 4-5 inch speakers in the front and rear they don't really play any useful low bass so having a "high pass" crosser for the four channels will prevent the speaker from blowing trying to produce low frequency sounds that we really won't hear on the bike anyway. I would suggest to roll off the speakers around 80-100 Hz using a 12-24 db crossover. Anything shallower I would bump it up to 200-250 Hz.
I put in 6.5" speakers in my saddlebags so I can run the rears full range.
Below are the five amp choices that I came up with. There are more but these will preserve the radio fader functionality that was important to me.
The Kenwood would be perfect for my needs if it had the built in crossover to remove the low bass out of the front speakers and the variable input gain controls. But since it is lacking those looking back the Soundstream or Rockford Fosgate would be better choices.
If I were to do it again I would do the following:
Polk db501's in the front.
Polk db651's in the rear saddlebags.
Soundstream or Rockford Fosgate amp under the seat or in the saddlebag.
BIG change would be to have GOOD headsets in the helmet and the intercom fully functional. That is what has taken me the longest and is the least documented.
But I should finish that up in the next two weeks.
If your Interstate did not have the factory rear speaker option you can get the rear speaker harness here:
http://www.electricalconnection.com/wire-harnesses/hrns_speaker.htm1. Pyle Marine grade. Cheapest and disposable. Mount this under the trunk if you don't have the CB or in the saddle bags. You get what you pay for. I can’t see this being great but in reality on a motorcycle doing 60-80(100) MPH does it have to be?
http://www.parts-express.com/pyle-plmra400-marine-waterproof-4-channel-amplifier--267-70402. Clarion 4 channel micro. If you care to keep all the electronics by Clarion. The radio and CB are by them. I don't like the permanently attached wires.
http://www.crutchfield.com/p_020XC1410/Clarion-XC1410.html?tp=357823. Kenwood 4 channel micro. The one I got. works well but wish I would have gotten the Soundstream or Rockford.
http://www.crutchfield.com/p_113KAM1804/Kenwood-KAC-M1804.html?tp=357824. Alpine 4 channel micro. Good solid amp, others have used. They mounted it in the front fairing.
http://www.crutchfield.com/p_500KTP445U/Alpine-KTP-445U-Power-Pack.html?tp=357825. Sounstream 4 channel micro. Most powerful, great features, compact.
http://www.crutchfield.com/p_530ST410KD/Soundstream-Stealth-ST4-1000D.html?tp=357826. Rockford Fosgate 4 channel micro. Most expensive, reliable, great features.
http://www.crutchfield.com/p_575PBR3004/Rockford-Fosgate-PBR300X4.html?tp=35782Since it is documented several times already I will not cover the speaker portion but instead just include the link to the Polk speaker install.
Fronts:
http://s161.photobucket.com/user/wixthedog/library/Front%20Speaker%20Upgrade?sort=4&page=1Rears:
http://s161.photobucket.com/user/wixthedog/library/Rear%20Speaker%20Upgrade?sort=4&page=1SO I know this is from 2014, but I was hoping there are still some subscribers following.
I pulled the trigger on a pair of DB401's for the front speaker last year (I didn't bother upgrading the rears, as most of the time I ride with the trunk off as a Supervalk). Today, I found this post and ordered the Soundstream ST4.1000D amp.
Now as someone who isn't a pro, but have done my fair share of small jobs like this following Youtube/guides/etc. I'm just wondering the pathway to getting this installed properly.
It's my understanding that the factory amp under the seat runs to the harness inside the right cover, and from there goes to the speakers? I guess I'm wondering exactly what should be going into the input(s) and output(s) of the new amp. Does it amplify the factory amp or replace it?
