under powered sub

Well we decided on what kind of subs to get now. Going with the Polk db212 720 watts rms http://www.polkaudio.com/caraudio/specs/db212/

Now for the amp, in the discription for the subs it says

The soundstream pca1000d 800w rms at 2 ohms   http://www.audio-warehouse.com/web/mdl/PCA1000D/detail.asp

Seems like a good match to me what do yall think?

Sounds fine.. But....."Single Voice Coil 4 Ohm drivers wired in parallel for a net 2-Ohm load, optimum for today's Class D subwoofer amplifiers".

As long as the amp is 1 ohm stable and you are using 2 - 4 ohm drivers. I don't know what they mean by "todays Class D subwoofer amplfiers"..seems like an assumption that all class D amplifiers are 1 ohm stable....I don't know if that's 100% true...but many are and apparently this one must be if they reccomend those ohms values.

Now it seems you are still a bit confused....so this is what I want you to say to yourself over and over until it sinks in...OK there tough guy??

Whatever ohms value you bridge to a STEREO amplifier.....you MUST cut that value in half ....that is what the amp runs at.

Whatever ohms value you connect to one channel of a STEREO amp...is what that channel will run at..same holds true for the other channel of the stereo amp.

In the case of a 4 channel amp...you MUST think of it has TWO - 2 channel amps and apply the above rules.

Whatever ohms you connect to a MONO amp..that is what it wil run at.

I can't simplify it any more then that.

Cool beans???

I have something else to add..at the risk of confusing you even more...lol..but I have enjoyed our conversations so here goes...

I don't know when you are getting the new equipment..but if you plan on working with what you have now...here's my opinion on it.

I agree that the Alpine amp is better suited for running your mids/highs...not only is it a very good sounding clean amplifier (assuming it is in original operating condition)..but..it was most likely built before dedicated subwoofer amplifiers were commonplace like today.

Now this by no means implys that it can't run subs and sound great..it most definatly can..power is power. As stated make sure the inputs are summed..if uncorrelated it will cut power and add distortion, which is way I am fiercly against using the boss amp in tandom with the Alpine..however..and this has not been discussed yet...does that Alpine amp have a built in low pass crossover???

If it does...no problem..if it does not...it will not sound very good on the subs.

One option if this is the case is to buy a seperate electronic crossover...since this is a temporary setup..any will do. They make very inexpensive electronic low pass x-overs..PAC has one....you hook up power...ground and remote...plug in the RCA's..and instant adjustable low pass cross over.

The other option is to use a passive crossover...the drawbacks>>>>  they rob power and are not adjustable..you would need to determine the frequency you wish to start low passing at and the final ohms load to determine the value of the inductor in mfds..to change the frequency you need more inductors...you can get the electronic one for about 15-20 bucks and have some adjusment to boot.

If the deck you are connecting the amp to has preamp sub-outs...ignore this entire post.

Ok...confused even more now??  lol

CORRECTION....!!!

"you would need to determine the frequency you wish to start low passing at and the final ohms load to determine the value of the inductor in mfds.."

I did NOT mean mfds (microfarads..that's for capacitors)..

Inductors (coils) are rated in Henries.....the value needed for subs will be valued in millihenries (mh)...typed before I thunk..but at least I caught it before someone else did and made me look like more of an ass.