Okay, lots going on here so we'll start at the beginning. For that example I was referring to using just the HU. The same scenario can come into play but that's if the amp you are using is only stable at a single load rating....say 4 ohms. Then if your 4 speakers were all 2 ohm you would want to wire them in series to make the load 4 ohms. Remember, wiring in series increases resistance and lowers volume because the signal can't flow as freely through the higher resistance. Parallel wiring does the opposite. It lowers resistance and increases volume but the amp is free flowing more power and needs to be designed to handle it and have the headroom so you don't fry it.

Now more specifically about your questions regarding the BT amp and speakers. First, since this equipment is designed by the same company it is meant to work together and compliment each other. That being said the 2180 is only a 2 channel amp. It is rated to be stable down to 2 ohms. The speakers are rated at 4 ohms. So you could wire the two 4 ohm speakers on each side in parallel. This would reduce the load to 2 ohms on each channel and the specs on BT's website for that amp show it will push 4 speakers when wired in parallel.

So, yes you could wire the four speakers to the BT2180. However I don't know if the HU's on the 2013's can be have the fade enabled. I would imagine it could be but if you're wired in parallel you won't have that option since both the front and rears on each side are connected to a single channel.

If you really wanted to be sure you were getting full performance out of all four speakers and the amp as you mentioned, I'd go with the 4180. One speaker per channel is always preferred and it gives you the opportunity to have the ability to fade if it's indeed an option available with a flash.

Think big picture, which it looks like for the most part you are. Based on the upgrades you've mentioned. If you're already planning on dropping the $$$ on 7.1's up front, 7.1's and the pods in the rear, and the amp. Now isn't the time to go all Scrooge on the purse strings for the sake of the $180 to go with the 4180 over the 2180..... unless you absolutely have to.

 

Thanks for the help little Mike, that clears it up, exactly what I was looking for.

 

No problem. Glad I was able to help.

 

I have committed to purchasing the Ultimate amp and speaker kit from biketronics w/pods.
My question is, can I use my Polk speakers (which I currently have mounted in the fairing) in my lowers and wire them parallel with the BT 7.1 speakers I will be installing?
if so, what mounting hardware do I need to buy to install those speakers into the lowers?
thank you guys so much for all the guidance and support and helping me lighten my wallet.

 

Which model Polks? The MM651's?

 

No. They are the db651 speakers. Specs are 4 ohms and 60 watts continuous handling. If they aren't sufficient I will just sell them to a buddy that has an electra glide with stock speakers.

 

The 4 ohm rating wouldn't be a problem. You could have just wired them in parallel. However, as usual, there is a but. I would be concerned with the RMS rating of 60 watts on those speakers. The BT amps are no joke and under rated in the power listing...meaning they often produce even more than what is listed. I'd be afraid of blowing those Polks especially considering that running in parallel lowers resistance which increases the output potential and thus the volume.

 

That's what I was concerned with. I will just sell them and stick with the BT setup. No sense in buying the mounting brackets just so I can blow my speakers. Eventually I may buy some better speakers and 6X9s.

 

If the reviews I've heard from people whose opinions I respect were even close to accurate, then with the sound improvement you'll get with the BT's you're not going to miss the Polks. You'll have some time to decide what other stuff you want to add before the itch sets back in to go after more sound, lol.

 

I'm positive i'll be more than happy with the setup i'm getting. Thank you very much for all the help.