FiestaJase

Hi Guys,

I've recently bought the following for my Ford Fiesta Mk4:-

Head Unit = Alpine CDA-9847R
http://caraudiosecurity.com/shop/pro...s_id/3224.html

Sub = In Phase XT 12
http://inphaseaudio.co.uk/products_xt12.asp

Amp = Legacy LA470
http://legacycaraudio.com/itempage.asp?model=LA470

6x9s = Song XSF692N (Well I bought these a while ago but I'm going to make use of them until I can upgrade them)
http://www.lowcostcaraudio.co.uk/sho...ZZproductJJ642

I'm planning to run the 6x9s off the head unit and the sub off the amp, however with the sub being rated at 700W RMS and a Peak of 1400W I'm wondering whether the amp will be powerful enough to run the sub? As the amp can be bridged into 1 x 600W Peak I believe, not RMS.. which means the Peak of the Amp won't even reach the RMS of the Sub!!!??? Does anyone have any ideas on whether the amp will be ok at running the Sub??

Also I am planning to Invert my Sub into a sealed box. Does anyone know if this is ok? I believe it is and have heard there are 2 main reasons for doing this. 1) To show off the magnet and motor of the sub. 2) To get more space inside the box. Therefore with the magnet not being inside the box, there will be more space. Also I guess with the motor and magnet outside the box it will help to keep it cooler. I've heard you have to Reverse the Polarity of the sub though If you wish to invert the sub. Is this correct and recommened??

Any comments or ideas will be greatly appreciated.

Many Thanks, Jase

SafeChav

Figures are very easy to get lost in. Ur sub is rated at 600w RMS Thats gotta be an expensive ass sub, 600w RMS would kill you!!!!

The amp will run it, most combinations work. The figures you have will also be at different impedences, at different frequencies so the figures will vary from one brand to another.

The best way perfromance wise to run a set up is to have an amp that is much more powerful than your speaker, as all amps etc have a THD% (Total Harmonic Distortion %), and when at full volume they do distort, so by having a bigger amp you dont need to crank it all the way to maximum therefore majorly reducing distortion, but on the other hand you can very easily blow your sub if your not careful.

Another thing not a lot of people know is you can kill a speaker by overpowering ASWELL AS UNDERPOWERING. This is known as "clipping", and basically the wave as you would look at it on the graph, gets its ends at highest amplitude clipped off.

Find a book on building enclosures, you use the Q factor of the speaker in a formula to calculate the capacity of the box needed, aswell as being able to pick your frequency cut off level and resonant frequency.